- TF-A - lists.trustedfirmware.org

by Soby Mathew

Hi Varun, AIU, Usually 2 keys are used to protect 2 different software contexts for enforcing the security boundary between them. This is the case for kernel and userspace. In TF-A, every BL image is allowed to choose the IA key to use, hence every BL image can have a separate IA key. Each BL image is executing within a single security domain and hence there is less use create a boundary within the BL image by using the 2nd key registers. The Compiler by default selects either IA or IB instruction key register to use by default. It cannot automatically make use of both key registers and it doesn't support the use of DA or DB yet I think. There are some function attributes which allow to use a different key at a function level, but the functions need to be marked out manually. But the requirement for creating the sub-domain within a BL image by specifying a different key for certain functions has not yet been seen AFAIK. Best Regards Soby Mathew From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A Sent: 13 July 2020 22:20 To: tf-a(a)lists.trustedfirmware.org Cc: Kalyani Chidambaram Vaidyanathan <kalyanic(a)nvidia.com> Subject: [TF-A] Pointer Authentication keys Hi, >From the initial read of the Arm ARM, there are multiple keys (instruction, data) provided for authenticating pointers. But the current implementation only writes IA key [1]. I would like to understand the thought process behind programming only one key here. AFAIU, we should enable all keys - IA, IB, DA, DB. -Varun [1] https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…

5 years, 3 months

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Re: [TF-A] Announcing some changes around the code review label in Gerrit

by Joanna Farley

Hi Julius, Sandrine is away on vacation so I thought I would follow up as we had a chat in one of our team meetings about the point below. > On 07/07/2020, 23:05, "TF-A on behalf of Julius Werner via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: >> IOW, you're fine with both options but you'd prefer to have different >> people setting MR+1 and COR+1 (or CR+1 in the special cases mentioned >> above), right? Just want to double-check I understood your position. >Right. So when we had +1/+2 CR before these changes we endeavoured to ensure that these were done by different people and if a maintainer gave a +1 they resisted also giving a +2 as we recognise having multiple eyes is always advantageous. So the general feeling was that this should be the recommended best practice. However, the feeling was also that this specific recommendation should not be strictly enforced by gerrit checking as on occasions it is possible to give both on simple patches and maintainers and code owners in this case can be trusted to make the correct choice. The enforcing of them in Gerrit should be viewed as an aid to try and avoid mistakes rather than strict control for as you say we don't expect people to intentionally break the rules. Perhaps a warning in this case can be made to remind folks what's best practice here. For now though as mentioned as we practice the new rules and recommendations we will use an honour system rather than strict enforcement along with updating the documented rules and recomendations. Thanks Joanna

5 years, 3 months

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Re: [TF-A] Deadlock in SGI RAS handling

by Soby Mathew

Hi Raghu, The Exception Handling framework (EHF) was designed to provide prioritization between the EL3 interrupts and EA although EA will always have highest priority since it cannot be blocked. In the case you describe, the driver in EL3 which is handling the RAS errors would need to ensure serialization of the events delivered to the S-EL0 payload somehow. This could be either via holding the event in a queue in EL3 till EL0 is done with processing the first event or the EL0 payload is capable of re-entry and can manage a queue internally. In case of MM, I suppose re-entry is not an option and hence a holding queue in EL3 driver needs to be implemented. The current implementation in sgi_ras.c doesn't do this currently as this was a PoC to showcase the RAS flow. Best Regards Soby Mathew > -----Original Message----- > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghu K > via TF-A > Sent: 13 July 2020 22:28 > To: tf-a(a)lists.trustedfirmware.org > Subject: [TF-A] Deadlock in SGI RAS handling > > Hi All, > > I was going through some code in sgi_ras.c and was wondering if the > situation mentioned below could cause a deadlock or if i'm missing > something. It seems like it is possible to deadlock if we enter MM in S- > EL0(say through an MM_COMMUNICATE SMC or perhaps an initial RAS > interrupt) followed by a SYNC EA or ASYNC EA on the same core. sgi_ras.c > seems like it registers the same handler for both interrupts and aborts. > While interrupts can be blocked/masked, SYNC EA's cannot be blocked(not > that i know of), and i don't see SErrors being blocked on the path to the EA > handler and entry to MM. If this situation does occur, it seems like we could > deadlock when the EA attempts to enter MM again in the interrupt handler. > Is there something that would prevent this situation from happening? > > > Thanks > Raghu > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 3 months

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Deadlock in SGI RAS handling

by Raghu K

Hi All, I was going through some code in sgi_ras.c and was wondering if the situation mentioned below could cause a deadlock or if i'm missing something. It seems like it is possible to deadlock if we enter MM in S-EL0(say through an MM_COMMUNICATE SMC or perhaps an initial RAS interrupt) followed by a SYNC EA or ASYNC EA on the same core. sgi_ras.c seems like it registers the same handler for both interrupts and aborts. While interrupts can be blocked/masked, SYNC EA's cannot be blocked(not that i know of), and i don't see SErrors being blocked on the path to the EA handler and entry to MM. If this situation does occur, it seems like we could deadlock when the EA attempts to enter MM again in the interrupt handler. Is there something that would prevent this situation from happening? Thanks Raghu

5 years, 3 months

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Pointer Authentication keys

by Varun Wadekar

Hi, >From the initial read of the Arm ARM, there are multiple keys (instruction, data) provided for authenticating pointers. But the current implementation only writes IA key [1]. I would like to understand the thought process behind programming only one key here. AFAIU, we should enable all keys - IA, IB, DA, DB. -Varun [1] https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…

5 years, 3 months

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TF-A Tech Forum Agenda @ Thr 16th July 2020 16:00-1700 BST

by Joanna Farley

Hi All, The next TF-A Tech Forum is scheduled for Thu 16th July 2020 16:00 – 17:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know. Agenda: * Secure EL2 SPM (Secure Partition Manager) Hafnium-based * In this TF-A Tech Forum session we present the status and open roadmap for the Secure Partition Manager firmware development. The TF-A SPM is the reference open source implementation for the PSA FF-A (Platform Security Architecture Firmware Framework for A-class) specification in the Secure world. It leverages the Armv8.4-Secure EL2 extension bringing virtualization technology in the Secure world (S-EL2 exception level). The development derives originally from the Google Hafnium project, which has been recently transitioned to https://www.trustedfirmware.org/ under the BSD 3-Clause license. * Optional TF-A Mailing List Topic Discussions If TF-A contributors have anything they wish to present at any future TF-A tech forum please contact me to have that scheduled. Previous sessions, both recording and presentation material can be found on the trustedfirmware.org TF-A Technical meeting webpage: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/ A scheduling tracking page is also available to help track sessions suggested and being prepared: https://developer.trustedfirmware.org/w/tf_a/tf-a-tech-forum-scheduling/ Final decisions on what will be presented will be shared a few days before the next meeting and shared on the TF-A mailing list. Thanks Joanna

5 years, 3 months

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New Defects reported by Coverity Scan for ARM-software/arm-trusted-firmware

by scan-admin＠coverity.com

Hi, Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. 4 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. New defect(s) Reported-by: Coverity Scan Showing 4 of 4 defect(s) ** CID 360537: Insecure data handling (TAINTED_SCALAR) ________________________________________________________________________________________________________ *** CID 360537: Insecure data handling (TAINTED_SCALAR) /plat/qemu/common/qemu_bl2_setup.c: 72 in update_dt() 66 67 if (dt_add_psci_cpu_enable_methods(fdt)) { 68 ERROR("Failed to add PSCI cpu enable methods in Device Tree\n"); 69 return; 70 } 71 >>> CID 360537: Insecure data handling (TAINTED_SCALAR) >>> Passing tainted variable "fdt->size_dt_struct" to a tainted sink. 72 ret = fdt_pack(fdt); 73 if (ret < 0) 74 ERROR("Failed to pack Device Tree at %p: error %d\n", fdt, ret); 75 } 76 77 void bl2_platform_setup(void) ** CID 360536: (TAINTED_SCALAR) ________________________________________________________________________________________________________ *** CID 360536: (TAINTED_SCALAR) /plat/rpi/rpi4/rpi4_bl31_setup.c: 249 in rpi4_prepare_dtb() 243 gic_int_prop[2] = cpu_to_fdt32(0x0f04); // all cores, level high 244 fdt_setprop(dtb, offs, "interrupts", gic_int_prop, 12); 245 246 offs = fdt_path_offset(dtb, "/chosen"); 247 fdt_setprop_string(dtb, offs, "stdout-path", "serial0"); 248 >>> CID 360536: (TAINTED_SCALAR) >>> Passing tainted variable "dtb->size_dt_struct" to a tainted sink. 249 ret = fdt_pack(dtb); 250 if (ret < 0) 251 ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret); 252 253 clean_dcache_range((uintptr_t)dtb, dtb_size(dtb)); 254 INFO("Changed device tree to advertise PSCI.\n"); /plat/rpi/rpi4/rpi4_bl31_setup.c: 220 in rpi4_prepare_dtb() 214 int ret, offs; 215 216 /* Return if no device tree is detected */ 217 if (fdt_check_header(dtb) != 0) 218 return; 219 >>> CID 360536: (TAINTED_SCALAR) >>> Passing tainted variable "dtb->totalsize" to a tainted sink. 220 ret = fdt_open_into(dtb, dtb, 0x100000); 221 if (ret < 0) { 222 ERROR("Invalid Device Tree at %p: error %d\n", dtb, ret); 223 return; 224 } 225 /plat/rpi/rpi4/rpi4_bl31_setup.c: 249 in rpi4_prepare_dtb() 243 gic_int_prop[2] = cpu_to_fdt32(0x0f04); // all cores, level high 244 fdt_setprop(dtb, offs, "interrupts", gic_int_prop, 12); 245 246 offs = fdt_path_offset(dtb, "/chosen"); 247 fdt_setprop_string(dtb, offs, "stdout-path", "serial0"); 248 >>> CID 360536: (TAINTED_SCALAR) >>> Passing tainted variable "dtb->size_dt_struct" to a tainted sink. 249 ret = fdt_pack(dtb); 250 if (ret < 0) 251 ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret); 252 253 clean_dcache_range((uintptr_t)dtb, dtb_size(dtb)); 254 INFO("Changed device tree to advertise PSCI.\n"); /plat/rpi/rpi4/rpi4_bl31_setup.c: 249 in rpi4_prepare_dtb() 243 gic_int_prop[2] = cpu_to_fdt32(0x0f04); // all cores, level high 244 fdt_setprop(dtb, offs, "interrupts", gic_int_prop, 12); 245 246 offs = fdt_path_offset(dtb, "/chosen"); 247 fdt_setprop_string(dtb, offs, "stdout-path", "serial0"); 248 >>> CID 360536: (TAINTED_SCALAR) >>> Passing tainted variable "dtb->size_dt_struct" to a tainted sink. 249 ret = fdt_pack(dtb); 250 if (ret < 0) 251 ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret); 252 253 clean_dcache_range((uintptr_t)dtb, dtb_size(dtb)); 254 INFO("Changed device tree to advertise PSCI.\n"); /plat/rpi/rpi4/rpi4_bl31_setup.c: 249 in rpi4_prepare_dtb() 243 gic_int_prop[2] = cpu_to_fdt32(0x0f04); // all cores, level high 244 fdt_setprop(dtb, offs, "interrupts", gic_int_prop, 12); 245 246 offs = fdt_path_offset(dtb, "/chosen"); 247 fdt_setprop_string(dtb, offs, "stdout-path", "serial0"); 248 >>> CID 360536: (TAINTED_SCALAR) >>> Passing tainted variable "dtb->size_dt_struct" to a tainted sink. 249 ret = fdt_pack(dtb); 250 if (ret < 0) 251 ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret); 252 253 clean_dcache_range((uintptr_t)dtb, dtb_size(dtb)); 254 INFO("Changed device tree to advertise PSCI.\n"); /plat/rpi/rpi4/rpi4_bl31_setup.c: 220 in rpi4_prepare_dtb() 214 int ret, offs; 215 216 /* Return if no device tree is detected */ 217 if (fdt_check_header(dtb) != 0) 218 return; 219 >>> CID 360536: (TAINTED_SCALAR) >>> Passing tainted variable "dtb->size_dt_strings" to a tainted sink. 220 ret = fdt_open_into(dtb, dtb, 0x100000); 221 if (ret < 0) { 222 ERROR("Invalid Device Tree at %p: error %d\n", dtb, ret); 223 return; 224 } 225 ** CID 360535: Insecure data handling (TAINTED_SCALAR) ________________________________________________________________________________________________________ *** CID 360535: Insecure data handling (TAINTED_SCALAR) /plat/renesas/rcar/bl2_plat_setup.c: 1005 in bl2_el3_early_platform_setup() 999 bl2_lossy_setting(1, LOSSY_ST_ADDR1, LOSSY_END_ADDR1, 1000 LOSSY_FMT1, LOSSY_ENA_DIS1, fcnlnode); 1001 bl2_lossy_setting(2, LOSSY_ST_ADDR2, LOSSY_END_ADDR2, 1002 LOSSY_FMT2, LOSSY_ENA_DIS2, fcnlnode); 1003 #endif 1004 >>> CID 360535: Insecure data handling (TAINTED_SCALAR) >>> Passing tainted variable "fdt->size_dt_struct" to a tainted sink. 1005 fdt_pack(fdt); 1006 NOTICE("BL2: FDT at %p\n", fdt); 1007 1008 if (boot_dev == MODEMR_BOOT_DEV_EMMC_25X1 || 1009 boot_dev == MODEMR_BOOT_DEV_EMMC_50X8) 1010 rcar_io_emmc_setup(); ** CID 346762: (TAINTED_SCALAR) ________________________________________________________________________________________________________ *** CID 346762: (TAINTED_SCALAR) /lib/libfdt/fdt_empty_tree.c: 37 in fdt_create_empty_tree() 31 return err; 32 33 err = fdt_finish(buf); 34 if (err) 35 return err; 36 >>> CID 346762: (TAINTED_SCALAR) >>> Passing tainted variable "buf->size_dt_struct" to a tainted sink. 37 return fdt_open_into(buf, buf, bufsize); /lib/libfdt/fdt_empty_tree.c: 33 in fdt_create_empty_tree() 27 return err; 28 29 err = fdt_end_node(buf); 30 if (err) 31 return err; 32 >>> CID 346762: (TAINTED_SCALAR) >>> Passing tainted variable "buf->size_dt_strings" to a tainted sink. 33 err = fdt_finish(buf); 34 if (err) 35 return err; 36 37 return fdt_open_into(buf, buf, bufsize); /lib/libfdt/fdt_empty_tree.c: 37 in fdt_create_empty_tree() 31 return err; 32 33 err = fdt_finish(buf); 34 if (err) 35 return err; 36 >>> CID 346762: (TAINTED_SCALAR) >>> Passing tainted variable "buf->totalsize" to a tainted sink. 37 return fdt_open_into(buf, buf, bufsize); /lib/libfdt/fdt_empty_tree.c: 37 in fdt_create_empty_tree() 31 return err; 32 33 err = fdt_finish(buf); 34 if (err) 35 return err; 36 >>> CID 346762: (TAINTED_SCALAR) >>> Passing tainted variable "buf->size_dt_strings" to a tainted sink. 37 return fdt_open_into(buf, buf, bufsize); ________________________________________________________________________________________________________ To view the defects in Coverity Scan visit, https://u2389337.ct.sendgrid.net/ls/click?upn=nJaKvJSIH-2FPAfmty-2BK5tYpPkl…

5 years, 3 months

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Re: [TF-A] Announcing some changes around the code review label in Gerrit

by Joanna Farley

+1 for re-introduction of 'Code-Review' label in addition to 'Code-Owner-Review' label. I would like to see the enforcement of authors of patches not being allowed to self review eventually for all labels. Hopefully we can enable maintainers who are not the author of deadlocked patches to allow the setting of all required +1's to labels is situations where this is necessary for admin purposes after due consideration. I agree though while this process is settling down an honour system is appropriate. Cheers Joanna On 01/07/2020, 08:56, "TF-A on behalf of Sandrine Bailleux via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Hi Julius, On 7/1/20 2:13 AM, Julius Werner wrote: > Hi Sandrine, > > Sounds like good changes in general! I'm curious what the ACLs are for > Code-Owner-Review? Is it tied to docs/about/maintainers.rst or just > based on the honor system? (I notice that I seem to be able to give a > +1 for code I'm not owning, but maybe that's because I am a > maintainer?) Right now, the ACLs are not tied to docs/about/maintainers.rst (any registered user could vote on this label) and it is just based on the honor system. However, I'd like this to be enforced in the future, we just haven't had the time to put the right tooling in place for that. Also we did not want to spend time on developing such scripts before we tried out these process changes in practice. If they proved too heavy or inconvenient, part of this work would have gone to waste. BTW, any help for the tooling is welcome! If you've got plugin configuration files or scripts we could reuse (with an appropriate license) or even tips on how to best set this up, please feel free to share these. > Also, are code owners allowed to +1 themselves (I think > we said we didn't want maintainers to do that, but for code owners I > could see how we might want to allow it since there are usually not > that many)? What do we do when someone uploads the first patch for a > new platform, do they just COR+1 themselves (since there is no code > owner yet)? That is indeed a grey area. As you say, many modules have a single code owner and we need to agree on how we would like such code reviews to be conducted. Thanks for starting this discussion! One option as you say would be to allow code owners to self-review their patches but I am not convinced we would gain anything out of this. It sounds like a tick-box exercise to me, an admin overhead just to get the patch through the system and I would like to avoid that as much as possible. It is likely that a patch submitter has already self-reviewed his code before posting a patch anyway. The alternative we've been discussing in the team is to call out another reviewer in these situations. I think that there is still value in having a second fresh pair of eyes on a patch. Even if the reviewer has no particular expertise on this specific module, they can still catch potential logic problems or structural issues in the code. The latter would be my preference. What do others think? > I think it might still be useful to retain the existing Code-Review as > a +1/-1 label next to the two new ones, just to allow other interested > parties to record their opinion (without it having any enforcing > effect on the merge). In other Gerrit instances I have used people > often like to give CR+1 as a "I'm not the one who needs to approve > this but I have looked at it and think it's fine" or a CR-1 as a "I > can't stop you from doing this but I still want to be clear that I > don't think it's a good idea". It allows people outside the official > approval process a clearer way to participate and can aid the official > approvers in their decisions (e.g. when I am reviewing a patch as a > maintainer that already has a CR-1 from someone else I know to pay > extra attention to their concerns, and it's more visible than just > some random comment further up in the list). What do you think? That's a very good idea, thanks! It also aligns with Javier's concerns, which sound perfectly valid to me. I think your proposal of having 3 distinct labels is better than having code owners and non-code owners voting on the same generic 'Code-Review' label, which is what Javier was suggesting. It clarifies further the intent of each label and as you say allows us to configure different rules for each (i.e. make the generic 'Code-Review' label informative/optional, while making the 'Code-Owner-Review' label mandatory for patch submission). I am gonna wait for others' opinions on this before changing the configuration in Gerrit again. I see Raghu agrees with this approach. If nobody disagrees by the end of the week, I'll do these changes on Monday. In the meantime, as discussed above, any registered user can vote on the new 'Code-Owner-Review' label so let's continue to use that for the rest of this week. Regards, Sandrine -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 3 months

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Re: [TF-A] Announcing some changes around the code review label in Gerrit

by Varun Wadekar

Hello Sandrine, IMO, the code review process has now evolved from the previous version. I am not too clear on the final outcome. Does it make sense to add a "lifecycle of a review" section to the initial proposal? -Varun -----Original Message----- From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandrine Bailleux via TF-A Sent: Monday, July 6, 2020 1:53 AM To: Julius Werner <jwerner(a)chromium.org> Cc: tf-a <tf-a(a)lists.trustedfirmware.org> Subject: Re: [TF-A] Announcing some changes around the code review label in Gerrit External email: Use caution opening links or attachments Hi Julius and all, As agreed and announced last week, I've now reintroduced the Code-Review label in addition to the Code-Owner-Review and Maintainer-Review ones. The Code-Review label is purely informational and won't influence whether a patch is submittable in Gerrit. Anyone should be able to vote on this label, if you face any issue please let me know. On 7/1/20 11:12 PM, Julius Werner wrote: >> BTW, any help for the tooling is welcome! If you've got plugin >> configuration files or scripts we could reuse (with an appropriate >> license) or even tips on how to best set this up, please feel free to >> share these. > > The Chromium Gerrit has an owners-enforcement system but I'm not > familiar with how exactly they set it up. I think they're using this > plugin > https://gerrit.googlesource.com/plugins/find-owners/+/refs/heads/maste > r and this is where it's integrated into Gerrit submission rules: > https://chromium.googlesource.com/chromiumos/+/refs/meta/config/rules. > pl . It works by having a file called OWNERS in certain directories > which sets the owners for the subtree below it, so we would have to > rewrite the current code owner list in that format if we wanted to use > it. This "find-owners" plugin sounds promising! Thanks for the pointers. I notice the "reviewers" plugin [1] is installed on review.tf.org but it does not sound as configurable as "find-owners". Rewriting the current code owners list to use the OWNERS format does not sound like a big task to me (just a dull one... could be scripted, though) so this approach definitely sounds worth investigating to me. [1] https://review.trustedfirmware.org/plugins/reviewers/Documentation/index.ht… > There also seems to be this completely separate plugin that claims to > do roughly the same thing, I have no idea where the difference is > between the two: > https://gerrit.googlesource.com/plugins/owners/+/refs/heads/master I notice the "find-owners" plugin documentation mentions that "this plugin works with Gerrit projects that use Android or Chromium compatible OWNERS files" so maybe they started off from the generic "owners" plugin and customized it for Android/Chromium's needs? Just a guess. Anyway, worth a look as well, thanks! [2] https://gerrit.googlesource.com/plugins/find-owners/+/refs/heads/master/src… >> One option as you say would be to allow code owners to self-review their >> patches but I am not convinced we would gain anything out of this. It >> sounds like a tick-box exercise to me, an admin overhead just to get the >> patch through the system and I would like to avoid that as much as >> possible. It is likely that a patch submitter has already self-reviewed >> his code before posting a patch anyway. >> >> The alternative we've been discussing in the team is to call out another >> reviewer in these situations. I think that there is still value in >> having a second fresh pair of eyes on a patch. Even if the reviewer has >> no particular expertise on this specific module, they can still catch >> potential logic problems or structural issues in the code. > > I definitely did not mean to suggest that these patches should not be > reviewed at all -- I was just talking about the Code-Owner-Review > label. There would still be a maintainer review, of course, and it > seems like a good idea to get additional reviews from other people > too. They just couldn't set the COR+1 bit once we start ACLing it. Right, I see (and agree with you). > Basically, each of these bits have their own purpose, and I would see > the purpose of the COR+1 bit to be that the person most familiar with > that particular piece of code has made sure that it fits in and > doesn't cause unexpected problems with certain quirky configurations > or something like that. That's important when, say, I make a generic > refactoring that touches a platform I'm unfamiliar with, but if the > code owner adds to their own platform that's probably already a given > and they are likely still the best person to judge that, even for > their own code. Yes, that makes sense to me. > That all code gets reviewed by people other than the author I would > see as a somewhat orthogonal concern that should be checked > independently. So maybe the rule could be that if the code owner sets > COR+1 for themselves, there needs to be at least one Code-Review+1 (if > we reintroduce that label) from another person (who is also not the > one setting Maintainer-Review+1) to make sure the minimum amount of > reviews stays the same. Or maybe these should all be completely > independent checks so every patch needs a Code-Owner-Review+1 (can be > from the author), a Maintainer-Review+1 (not from the author) and at > least two Code-Review+1 from people other than the author -- with the > normal expectation that when a maintainer or code owner reviews a > patch, they would also set Code-Review+1 (as a general sign that they > reviewed the patch) in addition to their special meaning flag. I still don't see the benefit of code owners setting COR+1 for themselves. I would think that a patch owner already reviews his own patch before posting it for review so a self COR+1 is just reinstating the obvious in my eyes. Your first suggestion (i.e. having at least one CR+1 from another person when a patch author cannot find another code owner to review their patches) sounds aligned with what I proposed earlier. Your second suggestion sounds a bit too heavy to me. The fact that people would have to replay their vote on several labels sounds like an admin overhead to me. I guess this would simplify the ACL configuration but I would prefer to avoid this if we can. So I suggest the following. We could have 2 ways to get a patch approved. 1) For patches that have multiple code owners: * COR+1 (not from patch owner) * MR+1 (not from patch owner, not from the person setting COR+1) 2) For patches that a have single code owner: * CR+1 (not from patch owner) * MR+1 (not from patch owner, not from the person setting CR+1) In 2), I like your suggestion of mandating 2 CR+1 but I fear this might be difficult to achieve in practice (simply because we might not have enough reviewers for this). Note that in some cases, we would need to mix both policies. If a patch modifies several modules, some of them having multiple code owners and others having a single code owner, we would apply one or the other policy for each module. How does that sound? Also, 1) assumes we always want different individuals doing the code-owner review and the maintainer review. I personally don't feel strongly about this split and I would be fine with the same person doing both types of review, as they are typically looking at different criteria. What do others think? Regards, Sandrine -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 3 months

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Re: [TF-A] Erroneous speculative AT workaround

by Soby Mathew

Thanks Andrew for raising the issue and Marc and Raghu for your inputs. The effect of stage 2 when Stage 1 is disabled is something that was overlooked in the workaround implementation. After some discussions this is what we currently understand regarding the problem. 1. EL3 does not modify the EL2 stage 1 translations and hence any speculative execution of AT execution in EL3 and resulting PTW and TLB caching should not be a problem as we always return to the same context in EL2. TF-A in EL3 need not worry about this. Also, we expect that future CPUs having v8.4 extensions for S-EL2 will have already corrected this errata. 2. Whenever the EL1/0 Stage 1 translations are switched in EL3 as part of switching the worlds, it should take Stage 2 into account. Hence disabling the Stage 1 MMU is not effective, as Marc pointed out, because speculative PTW can still take place using Stage 2 identity mapping. After discussion with James, we also realized that flipping the SCR_EL3.NS bit could take Stage 2 out of context (Stage 2 is not valid in secure world) leaving Stage 1 pointing to invalid translations. As discussed in previous emails, on Entry to EL3, if TCR_EL1.EPDx = 1 and SCTLR_EL3.M = 1, any speculative AT PTWs for EL1 context can be prevented (including Stage 2). So the fix as we currently understand would involve the following sequence : a. On Entry to EL3, save the incoming SCTLR_EL1.M and TCR_EL1.EPDx bits and set them (ensure TCR_EL1.EPDx =1 prior to SCTLR_EL1.M =1 using isb()) b. Prior to Exit from EL3, after the target context is restored, restore the SCTLR_EL1.M and TCR_EL1.EPDx bits. The above sequence now means that any use of AT instruction targeted at lower EL from EL3 that require PTW will fault. So prior to use of AT, ensure the PTW are re-enabled and disabled back again after the AT instructions. If the above sequence is agreed upon to resolve the errata, then we can work on a patch for the same. I suspect current el1 register save and restore sequence in TF-A is a bit unwieldy and we may need to analyze all the entry points to EL3 to ensure we cover everything. Best Regards Soby Mathew > -----Original Message----- > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Andrew > Scull via TF-A > Sent: 02 July 2020 09:20 > To: Raghu K <raghu.ncstate(a)icloud.com> > Cc: android-kvm(a)google.com; willdeacon(a)google.com; Marc Zyngier > <mzyngier(a)google.com>; tf-a(a)lists.trustedfirmware.org > Subject: Re: [TF-A] Erroneous speculative AT workaround > > On Wed, Jul 01, 2020 at 05:47:00PM -0700, Raghu K wrote: > > This is interesting. It appears that there is no way on entry to EL3 > > to guarantee that the out-of-context(el2 and el1) translation regimes > > are in a consistent state and on every entry into EL3, we have to > > conservatively assume that it is in an inconsistent state. This is > > because of the situation Andrew mentioned(interrupts to EL3 can occur at any > time). > > > > If this is the case, on EL3 entry: > > 1) For EL1, we will need to save SCTLR_EL1, set SCTLR_EL1.M = 1,.EPDx > > = 0 > > This would still be racing against any potential speculative execution of an AT > instruction upon the switch to EL3, IIUC. The window would be much smaller > but not entirely eliminated. > > For KVM, this would be enough as KVM will have already applied this > workaround (with Marc's corrections) whenever it is going to enter an > inconsistent state. However, other EL2 software may choose to handle the > errata differently, possibly going to the lengths of ensuring that no AT > instruction is ever mapped executable. > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a

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Re: [TF-A] Erroneous speculative AT workaround

by Raghu K

5 years, 4 months

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Re: [TF-A] Erroneous speculative AT workaround

by Raghu K

5 years, 4 months

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Re: [TF-A] Erroneous speculative AT workaround

by Raghu K

This is interesting. It appears that there is no way on entry to EL3 to guarantee that the out-of-context(el2 and el1) translation regimes are in a consistent state and on every entry into EL3, we have to conservatively assume that it is in an inconsistent state. This is because of the situation Andrew mentioned(interrupts to EL3 can occur at any time). If this is the case, on EL3 entry: 1) For EL1, we will need to save SCTLR_EL1, set SCTLR_EL1.M = 1,.EPDx = 0 2) Set whatever bits we need to for EL2 and S2 translations to not succeed(What are these?) 3) DSB, to ensure no speculative AT can be issued until completion of DSB, so any AT that occurs will not fill the TLB with bad translations. On exit(right before ERET), we need to restore the registers saved on entry, and have the ERET followed by a DSB so that there can be no speculative execution of AT instructions. Thanks Raghu On 7/1/20 5:54 AM, Marc Zyngier via TF-A wrote: > Hi Manish, > > On Wed, 1 Jul 2020 at 13:14, Manish Badarkhe <Manish.Badarkhe(a)arm.com> wrote: >> Hi Andrew, >> >> As per current implementation, in “el1_sysregs_context_restore” routine do below things: >> >> 1. TCR_EL1.EPD0 = 1 >> 2. TCR_EL1.EPD1 = 1 >> 3. SCTR_EL1.M = 0 >> 4. Isb >> Code snippet: >> mrs x9, tcr_el1 >> orr x9, x9, #TCR_EPD0_BIT >> orr x9, x9, #TCR_EPD1_BIT >> msr tcr_el1, x9 >> mrs x9, sctlr_el1 >> bic x9, x9, #SCTLR_M_BIT >> msr sctlr_el1, x9 >> isb >> This is to avoid PTW through while updating system registers at step 5 > Unfortunately, this doesn't prevent anything. > > If SCTLR_EL1.M is clear, TCR_EL1.EPDx don't mean much (S1 MMU is > disabled, no S1 page table walk), and you can still have S2 PTWs > (using an idmap for S1) and creating TLB corruption if these entry > alias with any S1 mapping that exists at EL1. > > Which is why KVM does *set* SCTLR_EL1.M, which prevents the use of a > 1:1 mapping at S1, and at which point the TCR_EL1.EPDx bits are > actually useful in preventing a PTW. > >> 5. Restore all system registers for El1 except SCTLR_EL1 and TCR_EL1 >> 6. isb() >> 7. restore SCTLR_EL1 and TCR_EL1 >> Code Snippet: >> ldr x9, [x0, #CTX_SCTLR_EL1] -> saved value from "el2_sysregs_context_save" >> msr sctlr_el1, x9 >> ldr x9, [x0, #CTX_TCR_EL1] >> msr tcr_el1, x9 >> >> As per above steps. SCTLR_EL1 get restored back with actual settings at step 7. >> Similar flow is present for “el2_sysregs_context_restore” to restore SCTLR_EL1 register. >> >> In conclusion, this routine temporarily clear M bit of SCTLR_EL1 to avoid speculation but restored it back >> to its original setting while leaving back to its caller. Please let us know whether this align with KVM >> workaround for speculative AT erratum. > It doesn't, unfortunately. I believe this code actively creates > problems on a system that is affected by speculative AT execution. > > I don't understand your rationale for touching SCTLR_EL2.M either if > you are not context-switching the EL2 S1 state: as far as I understand > no affected cores have S-EL2, so no switch should happen at this > stage. > > Thanks, > > M.

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Re: [TF-A] Erroneous speculative AT workaround

by Manish Badarkhe

Hi Andrew, As per current implementation, in “el1_sysregs_context_restore” routine do below things: 1. TCR_EL1.EPD0 = 1 2. TCR_EL1.EPD1 = 1 3. SCTR_EL1.M = 0 4. Isb Code snippet: mrs x9, tcr_el1 orr x9, x9, #TCR_EPD0_BIT orr x9, x9, #TCR_EPD1_BIT msr tcr_el1, x9 mrs x9, sctlr_el1 bic x9, x9, #SCTLR_M_BIT msr sctlr_el1, x9 isb This is to avoid PTW through while updating system registers at step 5 5. Restore all system registers for El1 except SCTLR_EL1 and TCR_EL1 6. isb() 7. restore SCTLR_EL1 and TCR_EL1 Code Snippet: ldr x9, [x0, #CTX_SCTLR_EL1] -> saved value from "el2_sysregs_context_save" msr sctlr_el1, x9 ldr x9, [x0, #CTX_TCR_EL1] msr tcr_el1, x9 As per above steps. SCTLR_EL1 get restored back with actual settings at step 7. Similar flow is present for “el2_sysregs_context_restore” to restore SCTLR_EL1 register. In conclusion, this routine temporarily clear M bit of SCTLR_EL1 to avoid speculation but restored it back to its original setting while leaving back to its caller. Please let us know whether this align with KVM workaround for speculative AT erratum. Thanks Manish Badarkhe On 01/07/2020, 17:02, "TF-A on behalf of Joanna Farley via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Thanks Andrew for the notification. We will look into it and get back to this thread. Thanks Joanna On 01/07/2020, 10:16, "TF-A on behalf of Andrew Scull via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Whilst looking at the speculative AT workaround in KVM, I compared it against the workaround in TF-A and noticed an inconsistency whereby TF-A **breaks** KVM's workaround. In `el1_sysregs_context_restore`, the M bit of SCTRL_EL1 is cleared however Linux requires this to be set for its workaround to be correct. If an exception is taken to EL3 partway through a VM context switch, e.g. a secure interrupt, causing a switch to the secure world, TF-A will reintroduce the possibility of TLB corruption. The above explains how it is broken for Linux's chosen workaround however TF-A will also have to be compatible with whatever workaround the EL2 software is using. Starting this thread with the issue identified and we can add more details as needed. Thanks Andrew -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

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Re: [TF-A] Erroneous speculative AT workaround

by Manish Badarkhe

+Updated comment for SCTLR_EL2 register restoration. On 01/07/2020, 17:45, "TF-A on behalf of Manish Badarkhe via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Hi Andrew, As per current implementation, in “el1_sysregs_context_restore” routine do below things: 1. TCR_EL1.EPD0 = 1 2. TCR_EL1.EPD1 = 1 3. SCTR_EL1.M = 0 4. Isb Code snippet: mrs x9, tcr_el1 orr x9, x9, #TCR_EPD0_BIT orr x9, x9, #TCR_EPD1_BIT msr tcr_el1, x9 mrs x9, sctlr_el1 bic x9, x9, #SCTLR_M_BIT msr sctlr_el1, x9 isb This is to avoid PTW through while updating system registers at step 5 5. Restore all system registers for El1 except SCTLR_EL1 and TCR_EL1 6. isb() 7. restore SCTLR_EL1 and TCR_EL1 Code Snippet: ldr x9, [x0, #CTX_SCTLR_EL1] -> saved value from "el2_sysregs_context_save" msr sctlr_el1, x9 ldr x9, [x0, #CTX_TCR_EL1] msr tcr_el1, x9 As per above steps. SCTLR_EL1 get restored back with actual settings at step 7. Similar flow is present for “el2_sysregs_context_restore” to restore SCTLR_EL2 register. In conclusion, this routine temporarily clear M bit of SCTLR_EL1 to avoid speculation but restored it back to its original setting while leaving back to its caller. Please let us know whether this align with KVM workaround for speculative AT erratum. Thanks Manish Badarkhe On 01/07/2020, 17:02, "TF-A on behalf of Joanna Farley via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Thanks Andrew for the notification. We will look into it and get back to this thread. Thanks Joanna On 01/07/2020, 10:16, "TF-A on behalf of Andrew Scull via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Whilst looking at the speculative AT workaround in KVM, I compared it against the workaround in TF-A and noticed an inconsistency whereby TF-A **breaks** KVM's workaround. In `el1_sysregs_context_restore`, the M bit of SCTRL_EL1 is cleared however Linux requires this to be set for its workaround to be correct. If an exception is taken to EL3 partway through a VM context switch, e.g. a secure interrupt, causing a switch to the secure world, TF-A will reintroduce the possibility of TLB corruption. The above explains how it is broken for Linux's chosen workaround however TF-A will also have to be compatible with whatever workaround the EL2 software is using. Starting this thread with the issue identified and we can add more details as needed. Thanks Andrew -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

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Re: [TF-A] Erroneous speculative AT workaround

by Joanna Farley

Thanks Andrew for the notification. We will look into it and get back to this thread. Thanks Joanna On 01/07/2020, 10:16, "TF-A on behalf of Andrew Scull via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Whilst looking at the speculative AT workaround in KVM, I compared it against the workaround in TF-A and noticed an inconsistency whereby TF-A **breaks** KVM's workaround. In `el1_sysregs_context_restore`, the M bit of SCTRL_EL1 is cleared however Linux requires this to be set for its workaround to be correct. If an exception is taken to EL3 partway through a VM context switch, e.g. a secure interrupt, causing a switch to the secure world, TF-A will reintroduce the possibility of TLB corruption. The above explains how it is broken for Linux's chosen workaround however TF-A will also have to be compatible with whatever workaround the EL2 software is using. Starting this thread with the issue identified and we can add more details as needed. Thanks Andrew -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

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Erroneous speculative AT workaround

by Andrew Scull

Whilst looking at the speculative AT workaround in KVM, I compared it against the workaround in TF-A and noticed an inconsistency whereby TF-A **breaks** KVM's workaround. In `el1_sysregs_context_restore`, the M bit of SCTRL_EL1 is cleared however Linux requires this to be set for its workaround to be correct. If an exception is taken to EL3 partway through a VM context switch, e.g. a secure interrupt, causing a switch to the secure world, TF-A will reintroduce the possibility of TLB corruption. The above explains how it is broken for Linux's chosen workaround however TF-A will also have to be compatible with whatever workaround the EL2 software is using. Starting this thread with the issue identified and we can add more details as needed. Thanks Andrew

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Re: [TF-A] Announcing some changes around the code review label in Gerrit

by Julius Werner

Hi Sandrine, Sounds like good changes in general! I'm curious what the ACLs are for Code-Owner-Review? Is it tied to docs/about/maintainers.rst or just based on the honor system? (I notice that I seem to be able to give a +1 for code I'm not owning, but maybe that's because I am a maintainer?) Also, are code owners allowed to +1 themselves (I think we said we didn't want maintainers to do that, but for code owners I could see how we might want to allow it since there are usually not that many)? What do we do when someone uploads the first patch for a new platform, do they just COR+1 themselves (since there is no code owner yet)? I think it might still be useful to retain the existing Code-Review as a +1/-1 label next to the two new ones, just to allow other interested parties to record their opinion (without it having any enforcing effect on the merge). In other Gerrit instances I have used people often like to give CR+1 as a "I'm not the one who needs to approve this but I have looked at it and think it's fine" or a CR-1 as a "I can't stop you from doing this but I still want to be clear that I don't think it's a good idea". It allows people outside the official approval process a clearer way to participate and can aid the official approvers in their decisions (e.g. when I am reviewing a patch as a maintainer that already has a CR-1 from someone else I know to pay extra attention to their concerns, and it's more visible than just some random comment further up in the list). What do you think? Best regards, Julius

5 years, 4 months

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Re: [TF-A] Announcing some changes around the code review label in Gerrit

by Javier Almansa Sobrino

Hi Sandrine, If my understanding is right, Code-Owner-Review is the equivalent to the old Code-Review+1 and therefore anyone can add a vote there, owner or not. If that is so, I think the current name might be misleading. Wouldn't it be better just "Code-Review", for instance? As an example, I am not code owner for Measure Boot, but sometimes I am requested to review the patches for it, so in that case it might lead to confusion if I give Code-Owner-Review score. What do you think? Best regards, Javier -----Original Message----- From: Sandrine Bailleux via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:Sandrine%20Bailleux%20via%20TF-A%20%3ctf-a@lists.trustedfirmware.org%3e>> Reply-To: Sandrine Bailleux <sandrine.bailleux(a)arm.com<mailto:Sandrine%20Bailleux%20%3csandrine.bailleux@arm.com%3e>> To: tf-a <tf-a(a)lists.trustedfirmware.org<mailto:tf-a%20%3ctf-a@lists.trustedfirmware.org%3e>> Subject: [TF-A] Announcing some changes around the code review label in Gerrit Date: Tue, 30 Jun 2020 13:29:00 +0000 Hello all, If you recall, the tf.org Project Maintenance Process [1] advocates a code review model where both code owners and maintainers need to review and approve a patch before it gets merged. Until now, the way we would record this in Gerrit was a bit cumbersome and ambiguous. * Code-Review+1 was for code owners to approve a patch. * Code-Review+2 was for maintainers to approve a patch. The submission rules in Gerrit were such that a patch needed a Code-Review+2 to be merged. This meant that if a maintainer was first to take a look at a patch and approved it (Code-Review+2), Gerrit would allow the patch to be merged without any code owners review. To align better with the Project Maintenance Process, I've done some changes in our Gerrit configuration. You will notice that the Code-Review label is gone and has been replaced by 2 new labels: * Code-Owner-Review * Maintainer-Review Stating the obvious but code owners are expected to vote on the Code-Owner-Review label and maintainers on the Maintainer-Review. Note that maintainers might also be code owners for some modules. If they are doing a "code owner" type of review on a patch, they would vote on the Code-Owner-Review label in this case. Any doubt, please ask. I hope I didn't break anything but if you notice any permissions problems (things you used to be able to do and cannot do anymore, or vice versa!) please let me know. One annoying consequence of this change is that if you've got some patches in review right now and got some votes on the former 'Code-Review' label, these have been partially lost. The history of review comments in Gerrit will still show that somebody had voted Code-Review -1/+1 on your patch but this will no longer appear in the labels summary frame and won't count towards the approvals required to get the patch merged. I could not think of a way to avoid this issue... This should only be temporary, while we transition all in-flight patches to the new code review model. Roughly: * Existing "Code-Review -1/+1" votes will have to be replayed as "Code-Owner-Review -1/+1". * Existing "Code-Review -2/+2" votes will have to be replayed as "Maintainer-Review -1/+1". Sorry for the inconvenience. I hope, once we've gone through the transition period, these changes will make the code review process clearer to everybody. I will update the TF-A documentation to explain all of this in the coming future. Best regards, Sandrine [1] https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…

5 years, 4 months

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New TrustedFirmware.org security incident process is now live

by Dan Handley

Hi all The new TrustedFirmware.org security incident process is now live. This process is described here: https://developer.trustedfirmware.org/w/collaboration/security_center/repor… Initially the process will be used for the following projects: TF-A, TF-M, OP-TEE and Mbed TLS. The security documentation for each project will be updated soon to reflect this change. If you are part of an organization that believes it should receive security vulnerability information before it is made public then please ask your relevant colleagues to register as Trusted Stakeholders as described here: https://developer.trustedfirmware.org/w/collaboration/security_center/trust… Note we prefer individuals in each organization to coordinate their registration requests with each other and to provide us with an email alias managed by your organization instead of us managing a long list of individual addresses. Best regards Dan. (on behalf of the TrustedFirmware.org security team)

5 years, 4 months

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Announcing some changes around the code review label in Gerrit

by Sandrine Bailleux

Hello all, If you recall, the tf.org Project Maintenance Process [1] advocates a code review model where both code owners and maintainers need to review and approve a patch before it gets merged. Until now, the way we would record this in Gerrit was a bit cumbersome and ambiguous. * Code-Review+1 was for code owners to approve a patch. * Code-Review+2 was for maintainers to approve a patch. The submission rules in Gerrit were such that a patch needed a Code-Review+2 to be merged. This meant that if a maintainer was first to take a look at a patch and approved it (Code-Review+2), Gerrit would allow the patch to be merged without any code owners review. To align better with the Project Maintenance Process, I've done some changes in our Gerrit configuration. You will notice that the Code-Review label is gone and has been replaced by 2 new labels: * Code-Owner-Review * Maintainer-Review Stating the obvious but code owners are expected to vote on the Code-Owner-Review label and maintainers on the Maintainer-Review. Note that maintainers might also be code owners for some modules. If they are doing a "code owner" type of review on a patch, they would vote on the Code-Owner-Review label in this case. Any doubt, please ask. I hope I didn't break anything but if you notice any permissions problems (things you used to be able to do and cannot do anymore, or vice versa!) please let me know. One annoying consequence of this change is that if you've got some patches in review right now and got some votes on the former 'Code-Review' label, these have been partially lost. The history of review comments in Gerrit will still show that somebody had voted Code-Review -1/+1 on your patch but this will no longer appear in the labels summary frame and won't count towards the approvals required to get the patch merged. I could not think of a way to avoid this issue... This should only be temporary, while we transition all in-flight patches to the new code review model. Roughly: * Existing "Code-Review -1/+1" votes will have to be replayed as "Code-Owner-Review -1/+1". * Existing "Code-Review -2/+2" votes will have to be replayed as "Maintainer-Review -1/+1". Sorry for the inconvenience. I hope, once we've gone through the transition period, these changes will make the code review process clearer to everybody. I will update the TF-A documentation to explain all of this in the coming future. Best regards, Sandrine [1] https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…

5 years, 4 months

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New Defects reported by Coverity Scan for ARM-software/arm-trusted-firmware

by scan-admin＠coverity.com

Hi, Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. 1 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. New defect(s) Reported-by: Coverity Scan Showing 1 of 1 defect(s) ** CID 360213: Null pointer dereferences (NULL_RETURNS) /plat/arm/common/arm_dyn_cfg.c: 96 in arm_bl1_set_mbedtls_heap() ________________________________________________________________________________________________________ *** CID 360213: Null pointer dereferences (NULL_RETURNS) /plat/arm/common/arm_dyn_cfg.c: 96 in arm_bl1_set_mbedtls_heap() 90 * In the latter case, if we still wanted to write in the DTB the heap 91 * information, we would need to call plat_get_mbedtls_heap to retrieve 92 * the default heap's address and size. 93 */ 94 95 tb_fw_config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, TB_FW_CONFIG_ID); >>> CID 360213: Null pointer dereferences (NULL_RETURNS) >>> Dereferencing "tb_fw_config_info", which is known to be "NULL". 96 tb_fw_cfg_dtb = tb_fw_config_info->config_addr; 97 98 if ((tb_fw_cfg_dtb != 0UL) && (mbedtls_heap_addr != NULL)) { 99 /* As libfdt use void *, we can't avoid this cast */ 100 void *dtb = (void *)tb_fw_cfg_dtb; 101 ________________________________________________________________________________________________________ To view the defects in Coverity Scan visit, https://u2389337.ct.sendgrid.net/ls/click?upn=nJaKvJSIH-2FPAfmty-2BK5tYpPkl…

5 years, 4 months

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TF-A Tech Forum Agenda @ Thr 2nd July 2020 16:00-1700 BST

by Joanna Farley

Hi All, The next TF-A Tech Forum is scheduled for Thu 2nd July 2020 16:00 – 17:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know. Agenda: * PSA Fuzz Testing - Presented by Gary Morrison * Originally developed for TF-M PSA API’s this is a different approach to Fuzz testing to that was previously presented in the TF-A SMC Fuzz testing session a few weeks back and provides a testing approach for a the different level of PSA API testing coming to TF-A. * Optional TF-A Mailing List Topic Discussions If TF-A contributors have anything they wish to present at any future TF-A tech forum please contact me to have that scheduled. Previous sessions, both recording and presentation material can be found on the trustedfirmware.org TF-A Technical meeting webpage: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/ A scheduling tracking page is also available to help track sessions suggested and being prepared: https://developer.trustedfirmware.org/w/tf_a/tf-a-tech-forum-scheduling/ Final decisions on what will be presented will be shared a few days before the next meeting and shared on the TF-A mailing list. Thanks Joanna

5 years, 4 months

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Re: [TF-A] How should we manage patches affecting multiple users?

by Joanna Farley

My take on this is perhaps not unexpectantly fairly aligned with Sandrine's. We as a project have over 30 platforms now up-streamed and the expectations is these are managed by the identified platform owners. We look to them to decide on which of any new capabilities offered are supported in their platforms. We have a strategy not to break up-streamed platforms except where we have clearly announced deprecation and this is all documented here https://trustedfirmware-a.readthedocs.io/en/latest/process/platform-compati… and where interfaces have changed and the work is trivial the submitter is expected to attempt to make a good effort to migrate platforms. To support this the current CI system hosted by Arm can only verify the builds of most platforms which is one of the gerrit approvals needed to merge a patch. Of course that does not mean the executables produced will necessarily run correctly which is where platform owners would need to assist with their own approvals and own testing if possible. With the Arm Juno platform and various Arm FVP models we do have the capability to test but that misses out all the other platforms up-streamed. With the OpenCI coming, which we owe a Tech-Forum session on BTW, the Juno and Arm FVP models will also be made available and if platform owners want they will be able to add their platforms to be tested if they want to invest the effort. Sadly migrating to the OpenCI will take time and will have to be delivered in phases but the hope is this will be useful to platform owners as well as for core changes with the visibility of the CI results. The various Arm platforms are generally owned and managed by different teams and go through the same processes as other non Arm platforms on getting patched up-streamed. So when new core features are added for new Arm hardware IP support or new software features that change behaviour as previously we still look to the platform owners to decide if they want support for these in their platforms. For some trivial changes that may be in the form of reviewing changes prepared but for others that may be deciding if they want to invest the effort to implement themselves. For core changes as well as making patches available via Gerrit for review we have been making more use of the TF-A mailing list to announce the patches are available. Indeed we are trying to make use of the mailing list while work is still in design to discuss openly decisions that need to be made which may or may not effect platforms. The Tech-Forum is also being used to present and discuss ideas and ongoing work. This is all being done to be more open about upcoming changes. We would welcome discussions on the mailing list and tech-forum sessions from platform owners about any subjects. This could be around coordinated support across platforms of new capabilities vs each platform following its own path. That of course holds challenges in coordination of effort and who's effort. Hopefully the direction of travel here for the project helps with some of the suggestions but happy to discuss more here on the mailing list of in a tech-forum meeting. Thanks Joanna On 25/06/2020, 03:16, "TF-A on behalf of Varun Wadekar via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Hi, >> As you said, even a small change might break a platform and unfortunately we're not in a position to detect that with the CI yet. I agree that this is a limitation today. If you remember, I have been advocating for announcing on the email alias when in doubt. That way we minimize surprises for the platform owners. >> IMO we cannot reasonably announce all such changes and I would think that contributors are responsible for keeping an eye on patches and testing them if they think they might be affected. I understand. We should announce on the mailing list, when in doubt. I strongly disagree with the second part of the statement though. Asking platform owners to keep an eye on every change defeats the purpose of upstreaming. The burden must lie on the implementer of a change to try and upgrade consumers. >> But I think that the same change might be considered as an improvement by some, and a useless/undesirable change by others. Possible. And then we take call as a community. If it makes sense for some platforms to move ahead, then that should be OK too. >> We might be able to reduce the number of build options in some cases but there will always be a need to retain most of them IMO Thinking out loud - maybe moving to runtime checks makes sense in some cases instead of makefile variables e.g. CPU erratas. We should look at each case individually. I guess, the main problem seems to be low level of testing. So any implementer wont be confident making a change that affects other platforms. That's when sending an email to the community makes sense. We tackle the situation as a team, instead of one person doing all the work. -Varun -----Original Message----- From: Sandrine Bailleux <sandrine.bailleux(a)arm.com> Sent: Wednesday, June 24, 2020 4:54 AM To: Varun Wadekar <vwadekar(a)nvidia.com> Cc: tf-a(a)lists.trustedfirmware.org Subject: Re: [TF-A] How should we manage patches affecting multiple users? External email: Use caution opening links or attachments Hi Varun, Thanks for sharing your opinion. On 6/20/20 1:55 AM, Varun Wadekar wrote: > Hello @Sandrine Bailleux, > > Thanks for starting the email chain. My response to the issues you flagged in the email below. > > 1. This seems to be a bit tricky. As a consumer of an API, one would expect that it works as advertised. If the behavior changes, thus affecting the expectations or assumptions surrounding the API, then they should be announced. With so many platforms in the tree, we should always assume that even a small change will break a platform. I agree. Whenever there is clear intention to change the expectations or assumptions of an API, this should be announced and discussed. However, there are cases where we might want to rework the implementation of an API (to clean the code for example), make some improvements or extend its functionality. All of that might be done with no intent to step outside of the API original scope but still subtly break some code. As you said, even a small change might break a platform and unfortunately we're not in a position to detect that with the CI yet. IMO we cannot reasonably announce all such changes and I would think that contributors are responsible for keeping an eye on patches and testing them if they think they might be affected. > 2. For improvements, we should strive to upgrade all consumers of the API/makefile/features. This will ensure that all platforms remain current and we reduce maintenance cost in the long run. I assume, that such improvements will give birth to additional configs/makefile settings/platform variables etc. We would be signing up for a lot of maintenance by allowing some platforms to lag. > > For straight forward changes (e.g. the change under discussion) I assume that the platforms will respond and we would get the changes merged relatively fast. For controversial features, this will spark a healthy discussion in the community. I agree with you in principle. But I think that the same change might be considered as an improvement by some, and a useless/undesirable change by others. For example, the change under discussion is an improvement from our point of view. It will lower the maintenance cost, as any new file added in the GIC driver in the future will be automatically pulled in by platforms that use the newly introduced GIC makefile, without the need to update all platforms makefiles. But this might not be what everyone wants, some platform owners might prefer continue cherry-picking specific GIC source files to retain control over what they include in their firmware. In this case, is it the right thing to do to "upgrade" them? I think this is debatable. Maybe a better alternative is to simply make people aware of the change, provide a link to how the migration was done for Arm platforms in this case, so that they've got an example to guide them if they wish to embrace the change for their own platform ports. > 3. For a case where the change breaks platforms, it makes sense to just upgrade all of them. > >>> Now the question we were pondering in Gerrit is, where does the responsibility of migrating all platforms/users lie for all these types of changes? Is the patch author responsible to do all the work? > > [VW] IMO, the author of such a patch is the best person to upgrade all affected platforms/users. The main reason being that he/she is already an expert for the patch. Agree that the patch author is an expert for his own patch but that does not mean he's also an expert on how his patch should be applied for another platform port he's not familiar with. > But, this might not be true in some cases where the author will need help from the community. For such cases, we should ask for help on the mailing list. Yes, I think such cases require collaboration indeed. > I also want to highlight the dangers of introducing make variables as a solution. The current situation is already unmanageable with so many build variables and weak handlers. We should try and avoid adding more. Not sure how this ties with the original discussions but I agree with you, we've got far too many build options in this project. This makes testing a lot harder, as it means we have hundreds of valid combinations of build options to verify. It also makes the code harder to read and understand because it is sprinkled with #ifdefs. Hopefully, switching to a KConfig-like configuration system in the future will help alleviate this issue, as at least it will allow us to express the valid combinations of build options in a more robust manner (today the build system tries to forbid invalid combinations but I am sure it's far from exhaustive in these types of checks) and also visualize what's been enabled/disabled more easily for a specific build. Even though I acknowledge this problem, I am not sure we can completely solve it. Firmware is not general-purpose software and it requires a lot more control over the features you include or not because of stricter memory and CPU constraints. I think people need a way to turn on/off features at a fine granularity. We might be able to reduce the number of build options in some cases but there will always be a need to retain most of them IMO. > Finally, I agree that there's no silver bullet and we have to deal with each situation differently. Communication is key, as you rightly said. As long we involve the community, we should be OK. > > -Varun > > -----Original Message----- > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of > Sandrine Bailleux via TF-A > Sent: Friday, June 19, 2020 2:57 AM > To: tf-a <tf-a(a)lists.trustedfirmware.org> > Subject: [TF-A] How should we manage patches affecting multiple users? > > External email: Use caution opening links or attachments > > > Hello everyone, > > I would like to start a discussion around the way we want to handle changes that affect all platforms/users. This subject came up in this code review [1]. > > I'll present my views on the subject and would like to know what others think. > > First of all, what do we mean by "changes that affect all platforms"? It would be any change that is not self-contained within a platform port. > IOW, a change in some file outside of the plat/ directory. It could be in a driver, in a library, in the build system, in the platform interfaces called by the generic code... the list goes on. > > 1. Some are just implementation changes, they leave the interfaces unchanged. These do not break other platforms builds since the call sites don't need to be updated. However, they potentially change the responsibilities of the interface, in which case this might introduce behavioral changes that all users of the interface need to be aware of and adapt their code to. > > 2. Some other changes might introduce optional improvements. They introduce a new way of doing things, perhaps a cleaner or more efficient one. Users can safely stay with the old way of doing things without fear of breakage but they would benefit from migrating. > > This is the case of Alexei's patch [1], which introduces an > intermediate > GICv2 makefile, that Arm platforms now include instead of pulling each individual file by themselves. At this point, it is just an improvement that introduces an indirection level in the build system. This is an improvement in terms of maintainability because if we add a new essential file to this driver in the future, we'll just need to add it in this new GICv2 makefile without having to update all platforms makefiles. However, platform makefiles can continue to pull in individual files if they wish to. > > 3. Some other changes might break backwards compatibility. This is something we should avoid as much as possible and we should always strive to provide a migration path. But there are cases where there might be no other way than to break things. In this case, all users have to be migrated. > > > Now the question we were pondering in Gerrit is, where does the responsibility of migrating all platforms/users lie for all these types of changes? Is the patch author responsible to do all the work? > > I think it's hard to come up with a one-size-fits-all answer. It really depends on the nature of changes, their consequences, the amount of work needed to do the migration, the ability for the patch author to test these changes, to name a few. > > I believe the patch author should migrate all users on a best-effort basis. If it's manageable then they should do the work and propose a patch to all affected users for them to review and test on their platforms. > > On the other hand, if it's too much work or impractical, then I think the best approach would be for the patch author to announce and discuss the changes on this mailing list. In some scenarios, the changes might be controversial and not all platform owners might agree that the patch brings enough benefit compared to the migration effort, in which case the changes might have to be withdrawn or re-thought. In any case, I believe communication is key here and no one should take any unilateral decision on their own if it affects other users. > > I realize this is a vast subject and that we probably won't come up with an answer/reach an agreement on all the aspects of the question. But I'd be interested in hearing other contributors' view and if they've got any experience managing these kinds of issues, perhaps in other open source project. > > Best regards, > Sandrine > > [1] > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4538 > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a > -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] Question on authenticating FIP images

by Sandrine Bailleux

Hi, On 6/25/20 3:24 AM, Raghu K via TF-A wrote: > One option you can look at is in bl1_fwu.c if you already haven't, in > bl1_fwu_image_auth() function, that uses the auth_mod_verify_img, which > is provided an image id, address and size. You can repeatedly call this > function on the different image ID's that you have in your FIP. You will > likely need to calculate the address to pass to this function based on > reading the FIP header(maybe you can use the IO framework for this by > opening different image ID's). > Don't think there is a straight forward way but what you are trying to > do should be achievable using existing code, rearranged to fit your needs. Yes, Raghu's approach sounds right to me. As he pointed out, this is not something that's supported out of the box because the firmware update feature is normally invoked through an SMC into BL1 as part of the firmware update flow early during the boot. Things are different in your case as you're looking to provide this feature much later as a runtime service so this will surely require some amount of tweaking but sounds feasible to me. Best regards, Sandrine > > Thanks > Raghu > > On 6/24/20 12:42 PM, arm in-cloud via TF-A wrote: >> Hi Sandrine, >> >> Waiting for your suggestions on this query. >> >> Thanks >> >> On Mon, Jun 22, 2020 at 3:40 PM arm in-cloud via TF-A >> <tf-a(a)lists.trustedfirmware.org >> <mailto:tf-a@lists.trustedfirmware.org>> wrote: >> >> <Posting the question to tf-a mailing list from Maniphest and >> copied all previous conversation> >> >> Hi, >> >> On our boards I have an external security chip which communicates >> with AP (application processor) over a encrypted communication >> channel. I have a communication driver/PTA running in a Secure >> Playload (OPTEE) running in S-EL1. My firmware update workflow >> (FIP.BIN) is as below. >> >> In our design, we have QSPI from where AP boots up (regular TF-A >> workflow) this QSPI is also accessible from external Security chip >> (which is responsible for AP/SOC's firmware update) >> On software side, I have a Non-Secure application which receives >> the prebuilt binary (FIP.BIN) it chopps the binary in fixed sized >> buffers and send to OPTEE-PTA which internally sends the binary to >> Security chip (which then validates and writes to QSPI). >> >> Now in this firmware update flow, I want to do following things. >> >> 1. I want to validate/authenticate the FIP image before sending >> to security chip. If it authentication is successful only then >> send the image to security chip. >> >> This is what I am planning:- >> >> 1. Receive the whole FIP.BIN from NS-APP and store it in RAM (in >> OPTEE's RAM) >> 2. I am planning to implement a SIP service in TF-A which will >> receive the address and size of FIP.BIN in RAM. >> 3. Calls in to auth_mod driver for authentication of the image. >> >> I don't want to update the images immediately I just needs to >> authenticate the images within FIP.BIN >> >> To design this feature, I started looking in to BL1 & BL2 code but >> not sure how much piece if code I can reuse or use. >> Also I looked in to fwu test apps if I can mimic something but >> looks the fwu implementation is absolutely different. >> >> My question is how do I just use the authentication functionality >> available in TF-A for my purpose. >> >> Appreciate your help! >> >> >> >> >> sandrine-bailleux-arm >> <https://developer.trustedfirmware.org/p/sandrine-bailleux-arm/> added >> a subscriber: sandrine-bailleux-arm >> <https://developer.trustedfirmware.org/p/sandrine-bailleux-arm/>.Tue, >> Jun 16, 6:50 AM <https://developer.trustedfirmware.org/T763#9015> >> >> <https://developer.trustedfirmware.org/T763#> >> >> Hi, >> >> Apologies for the delay, I had missed this ticket... Generally >> speaking, it's better to post questions on the TF-A mailing list >> [1], it's got far better visibility than Maniphest (which few >> people monitor I believe) and you are more likely to get a quick >> answer there. >> >> First of all, I've got a few questions that would help me >> understand your design. >> >> 1. You say that OPTEE-PTA would store the FIP image in its RAM. I >> am assuming this is secure RAM, that only secure software can >> access, right? If not, this would not seem very secure to me, >> as the normal world software could easily change the FIP image >> after it has been authenticated and replace it with some >> malicious firmware. >> >> 2. You'd like to implement a SiP service in TF-A to authenticate >> the FIP image, given its base address and size. Now I am >> guessing this would be an address in OPTEE's RAM, right? >> >> 3. What cryptographic key would sign the FIP image? Would TF-A >> have access to this key to authenticate it? >> >> 4. What would need authentication? The FIP image as a monolithic >> blob, or each individual image within this FIP? And in the >> latter case, would all images be authenticated using the same >> key or would different images be signed with different keys? >> >> Now, coming back to where to look into TF-A source code. You're >> looking in the right place, all Trusted Boot code is indeed built >> into BL1 and BL2 in TF-A. The following two documents detail how >> the authentication framework and firmware update flow work in TF-A >> and are worth reading if you haven't done so already: >> >> https://trustedfirmware-a.readthedocs.io/en/latest/design/auth-framework.ht… >> https://trustedfirmware-a.readthedocs.io/en/latest/components/firmware-upda… >> >> I reckon you'd want to reuse the cryptographic module in your >> case. It provides a callback to verify the signature of some >> payload, see [2] and include/drivers/auth/crypto_mod.h. However, I >> expect it won't be straight forward to reuse this code outside of >> its context, as it expects DER-encoded data structures following a >> specific ASN.1 format. Typically when used in the TF-A trusted >> boot flow, these are coming from X.509 certificates, which already >> provide the data structures in the right format. >> >> Best regards, >> Sandrine Bailleux >> >> [1] https://lists.trustedfirmware.org/mailman/listinfo/tf-a >> [2] https://trustedfirmware-a.readthedocs.io/en/latest/design/auth-framework.ht… >> >> >> arm-in-cloud >> <https://developer.trustedfirmware.org/p/arm-in-cloud/> added a >> comment.Edited · Wed, Jun 17, 11:42 AM >> <https://developer.trustedfirmware.org/T763#9018> >> >> <https://developer.trustedfirmware.org/T763#> >> >> Thank you Sandrine for your feedback. >> >> Following are the answers to your questions: >> >> 1. Yes, the image will be stored in to OPTEEs secured memory. I >> am guessing TF-A gets access to this memory. >> 2. Yes, the OPTEE's secure memory address and Size will be passed >> to the SiP service running in TF-A. >> 3. These are RSA keys, in my case only TF-A has access to these >> keys. On a regular boot these are the same keys used to >> authenticate the images (BL31, BL32 & BL33) in the FIP stored >> in the QSPI. >> 4. Yes all images will be authenticated using same key. >> >> Thanks for the documentation links, from the firmware-update doc. >> I am mainly trying to use IMAGE_AUTH part. In my case COPY is >> already done just needs AUTH part and once AUTH is successful, >> optee will pass that payload the security chip for update. And >> after rebooting my device will boot with new firmware. (In my case >> we always reboot after firmware updates). >> >> Do you want me to post this query again on the TF-A mailing list? >> >> Thank you! >> >> >> >> sandrine-bailleux-arm >> <https://developer.trustedfirmware.org/p/sandrine-bailleux-arm/> added >> a comment.Fri, Jun 19, 3:09 AM >> <https://developer.trustedfirmware.org/T763#9032> >> >> <https://developer.trustedfirmware.org/T763#> >> >> Hi, >> >> OK I understand a bit better, thanks for the details. >> >> Do you want me to post this query again on the TF-A mailing list? >> >> If it's not too much hassle for you then yes, I think it'd be >> preferable to continue the discussion on the TF-A mailing list. I >> will withhold my comments until then. >> >> >> >> -- >> TF-A mailing list >> TF-A(a)lists.trustedfirmware.org <mailto:TF-A@lists.trustedfirmware.org> >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a >> >> > >

5 years, 4 months

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Re: [TF-A] Unit Test tech forum follow-up

by Varun Wadekar

Hello Lauren, Thanks for answering the open items from the tech forum. Just curious, do you know if CppUTest can also consider a set of C files as a unit instead of a single function? This is the policy we have adopted internally, but with an automated tool to generate the unit tests. Cheers, Varun From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Lauren Wehrmeister via TF-A Sent: Thursday, June 25, 2020 10:52 AM To: tf-a(a)lists.trustedfirmware.org Subject: [TF-A] Unit Test tech forum follow-up External email: Use caution opening links or attachments Following up about some questions from my presentation at the tech forum on the TF-A unit testing framework. In regards to the other tool that was investigated alongside CppUTest, it was Google Test<https://github.com/google/googletest>. The main reason for choosing CppUTest was that it is easily portable to new platforms and has a small footprint despite its feature set. This could be very useful if we want to use it on hardware (not on the host machine) in the future, even if it only has a small amount of memory. Google test is very good for testing user space applications, but most of its features require pthread, file system, and other services of the operating system which we usually don't have in an embedded environment. So we chose CppUTest because it fits for both host and target based testing so we won't end up using different frameworks in the same project. Something to note is that CppUTest has an option<https://cpputest.github.io/manual.html#gtest> for running Google Test based test cases too, but the intention is to keep the framework clean by using only CppUTest. Also c-picker can support parsing large data structures since the tool uses PyYAML for parsing the config files and clang for processing the source files. Thanks, Lauren

5 years, 4 months

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1
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Unit Test tech forum follow-up

by Lauren Wehrmeister

Following up about some questions from my presentation at the tech forum on the TF-A unit testing framework. In regards to the other tool that was investigated alongside CppUTest, it was Google Test<https://github.com/google/googletest>. The main reason for choosing CppUTest was that it is easily portable to new platforms and has a small footprint despite its feature set. This could be very useful if we want to use it on hardware (not on the host machine) in the future, even if it only has a small amount of memory. Google test is very good for testing user space applications, but most of its features require pthread, file system, and other services of the operating system which we usually don't have in an embedded environment. So we chose CppUTest because it fits for both host and target based testing so we won't end up using different frameworks in the same project. Something to note is that CppUTest has an option<https://cpputest.github.io/manual.html#gtest> for running Google Test based test cases too, but the intention is to keep the framework clean by using only CppUTest. Also c-picker can support parsing large data structures since the tool uses PyYAML for parsing the config files and clang for processing the source files. Thanks, Lauren

5 years, 4 months

1
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Re: [TF-A] How should we manage patches affecting multiple users?

by Varun Wadekar

Hello @Sandrine Bailleux, Thanks for starting the email chain. My response to the issues you flagged in the email below. 1. This seems to be a bit tricky. As a consumer of an API, one would expect that it works as advertised. If the behavior changes, thus affecting the expectations or assumptions surrounding the API, then they should be announced. With so many platforms in the tree, we should always assume that even a small change will break a platform. 2. For improvements, we should strive to upgrade all consumers of the API/makefile/features. This will ensure that all platforms remain current and we reduce maintenance cost in the long run. I assume, that such improvements will give birth to additional configs/makefile settings/platform variables etc. We would be signing up for a lot of maintenance by allowing some platforms to lag. For straight forward changes (e.g. the change under discussion) I assume that the platforms will respond and we would get the changes merged relatively fast. For controversial features, this will spark a healthy discussion in the community. 3. For a case where the change breaks platforms, it makes sense to just upgrade all of them. >> Now the question we were pondering in Gerrit is, where does the responsibility of migrating all platforms/users lie for all these types of changes? Is the patch author responsible to do all the work? [VW] IMO, the author of such a patch is the best person to upgrade all affected platforms/users. The main reason being that he/she is already an expert for the patch. But, this might not be true in some cases where the author will need help from the community. For such cases, we should ask for help on the mailing list. I also want to highlight the dangers of introducing make variables as a solution. The current situation is already unmanageable with so many build variables and weak handlers. We should try and avoid adding more. Finally, I agree that there's no silver bullet and we have to deal with each situation differently. Communication is key, as you rightly said. As long we involve the community, we should be OK. -Varun -----Original Message----- From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandrine Bailleux via TF-A Sent: Friday, June 19, 2020 2:57 AM To: tf-a <tf-a(a)lists.trustedfirmware.org> Subject: [TF-A] How should we manage patches affecting multiple users? External email: Use caution opening links or attachments Hello everyone, I would like to start a discussion around the way we want to handle changes that affect all platforms/users. This subject came up in this code review [1]. I'll present my views on the subject and would like to know what others think. First of all, what do we mean by "changes that affect all platforms"? It would be any change that is not self-contained within a platform port. IOW, a change in some file outside of the plat/ directory. It could be in a driver, in a library, in the build system, in the platform interfaces called by the generic code... the list goes on. 1. Some are just implementation changes, they leave the interfaces unchanged. These do not break other platforms builds since the call sites don't need to be updated. However, they potentially change the responsibilities of the interface, in which case this might introduce behavioral changes that all users of the interface need to be aware of and adapt their code to. 2. Some other changes might introduce optional improvements. They introduce a new way of doing things, perhaps a cleaner or more efficient one. Users can safely stay with the old way of doing things without fear of breakage but they would benefit from migrating. This is the case of Alexei's patch [1], which introduces an intermediate GICv2 makefile, that Arm platforms now include instead of pulling each individual file by themselves. At this point, it is just an improvement that introduces an indirection level in the build system. This is an improvement in terms of maintainability because if we add a new essential file to this driver in the future, we'll just need to add it in this new GICv2 makefile without having to update all platforms makefiles. However, platform makefiles can continue to pull in individual files if they wish to. 3. Some other changes might break backwards compatibility. This is something we should avoid as much as possible and we should always strive to provide a migration path. But there are cases where there might be no other way than to break things. In this case, all users have to be migrated. Now the question we were pondering in Gerrit is, where does the responsibility of migrating all platforms/users lie for all these types of changes? Is the patch author responsible to do all the work? I think it's hard to come up with a one-size-fits-all answer. It really depends on the nature of changes, their consequences, the amount of work needed to do the migration, the ability for the patch author to test these changes, to name a few. I believe the patch author should migrate all users on a best-effort basis. If it's manageable then they should do the work and propose a patch to all affected users for them to review and test on their platforms. On the other hand, if it's too much work or impractical, then I think the best approach would be for the patch author to announce and discuss the changes on this mailing list. In some scenarios, the changes might be controversial and not all platform owners might agree that the patch brings enough benefit compared to the migration effort, in which case the changes might have to be withdrawn or re-thought. In any case, I believe communication is key here and no one should take any unilateral decision on their own if it affects other users. I realize this is a vast subject and that we probably won't come up with an answer/reach an agreement on all the aspects of the question. But I'd be interested in hearing other contributors' view and if they've got any experience managing these kinds of issues, perhaps in other open source project. Best regards, Sandrine [1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4538 -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] Question on authenticating FIP images

by Raghu K

5 years, 4 months

1
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Re: [TF-A] Question on authenticating FIP images

by arm in-cloud

Hi Sandrine, Waiting for your suggestions on this query. Thanks On Mon, Jun 22, 2020 at 3:40 PM arm in-cloud via TF-A < tf-a(a)lists.trustedfirmware.org> wrote: > <Posting the question to tf-a mailing list from Maniphest and copied all > previous conversation> > > Hi, > > On our boards I have an external security chip which communicates with AP > (application processor) over a encrypted communication channel. I have a > communication driver/PTA running in a Secure Playload (OPTEE) running in > S-EL1. My firmware update workflow (FIP.BIN) is as below. > > In our design, we have QSPI from where AP boots up (regular TF-A workflow) > this QSPI is also accessible from external Security chip (which is > responsible for AP/SOC's firmware update) > On software side, I have a Non-Secure application which receives the > prebuilt binary (FIP.BIN) it chopps the binary in fixed sized buffers and > send to OPTEE-PTA which internally sends the binary to Security chip (which > then validates and writes to QSPI). > > Now in this firmware update flow, I want to do following things. > > 1. I want to validate/authenticate the FIP image before sending to > security chip. If it authentication is successful only then send the image > to security chip. > > This is what I am planning:- > > 1. Receive the whole FIP.BIN from NS-APP and store it in RAM (in > OPTEE's RAM) > 2. I am planning to implement a SIP service in TF-A which will receive > the address and size of FIP.BIN in RAM. > 3. Calls in to auth_mod driver for authentication of the image. > > I don't want to update the images immediately I just needs to authenticate > the images within FIP.BIN > > To design this feature, I started looking in to BL1 & BL2 code but not > sure how much piece if code I can reuse or use. > Also I looked in to fwu test apps if I can mimic something but looks the > fwu implementation is absolutely different. > > My question is how do I just use the authentication functionality > available in TF-A for my purpose. > > Appreciate your help! > > > > > sandrine-bailleux-arm > <https://developer.trustedfirmware.org/p/sandrine-bailleux-arm/> added a > subscriber: sandrine-bailleux-arm > <https://developer.trustedfirmware.org/p/sandrine-bailleux-arm/>.Tue, Jun > 16, 6:50 AM <https://developer.trustedfirmware.org/T763#9015> > > <https://developer.trustedfirmware.org/T763#> > > Hi, > > Apologies for the delay, I had missed this ticket... Generally speaking, > it's better to post questions on the TF-A mailing list [1], it's got far > better visibility than Maniphest (which few people monitor I believe) and > you are more likely to get a quick answer there. > > First of all, I've got a few questions that would help me understand your > design. > > 1. You say that OPTEE-PTA would store the FIP image in its RAM. I am > assuming this is secure RAM, that only secure software can access, right? > If not, this would not seem very secure to me, as the normal world software > could easily change the FIP image after it has been authenticated and > replace it with some malicious firmware. > > > 1. You'd like to implement a SiP service in TF-A to authenticate the > FIP image, given its base address and size. Now I am guessing this would be > an address in OPTEE's RAM, right? > > > 1. What cryptographic key would sign the FIP image? Would TF-A have > access to this key to authenticate it? > > > 1. What would need authentication? The FIP image as a monolithic blob, > or each individual image within this FIP? And in the latter case, would all > images be authenticated using the same key or would different images be > signed with different keys? > > Now, coming back to where to look into TF-A source code. You're looking in > the right place, all Trusted Boot code is indeed built into BL1 and BL2 in > TF-A. The following two documents detail how the authentication framework > and firmware update flow work in TF-A and are worth reading if you haven't > done so already: > > > https://trustedfirmware-a.readthedocs.io/en/latest/design/auth-framework.ht… > > https://trustedfirmware-a.readthedocs.io/en/latest/components/firmware-upda… > > I reckon you'd want to reuse the cryptographic module in your case. It > provides a callback to verify the signature of some payload, see [2] and > include/drivers/auth/crypto_mod.h. However, I expect it won't be straight > forward to reuse this code outside of its context, as it expects > DER-encoded data structures following a specific ASN.1 format. Typically > when used in the TF-A trusted boot flow, these are coming from X.509 > certificates, which already provide the data structures in the right format. > > Best regards, > Sandrine Bailleux > > [1] https://lists.trustedfirmware.org/mailman/listinfo/tf-a > [2] > https://trustedfirmware-a.readthedocs.io/en/latest/design/auth-framework.ht… > > > arm-in-cloud <https://developer.trustedfirmware.org/p/arm-in-cloud/> added > a comment.Edited · Wed, Jun 17, 11:42 AM > <https://developer.trustedfirmware.org/T763#9018> > > <https://developer.trustedfirmware.org/T763#> > > Thank you Sandrine for your feedback. > > Following are the answers to your questions: > > 1. Yes, the image will be stored in to OPTEEs secured memory. I am > guessing TF-A gets access to this memory. > 2. Yes, the OPTEE's secure memory address and Size will be passed to > the SiP service running in TF-A. > 3. These are RSA keys, in my case only TF-A has access to these keys. > On a regular boot these are the same keys used to authenticate the images > (BL31, BL32 & BL33) in the FIP stored in the QSPI. > 4. Yes all images will be authenticated using same key. > > Thanks for the documentation links, from the firmware-update doc. I am > mainly trying to use IMAGE_AUTH part. In my case COPY is already done just > needs AUTH part and once AUTH is successful, optee will pass that payload > the security chip for update. And after rebooting my device will boot with > new firmware. (In my case we always reboot after firmware updates). > > Do you want me to post this query again on the TF-A mailing list? > > Thank you! > > > > sandrine-bailleux-arm > <https://developer.trustedfirmware.org/p/sandrine-bailleux-arm/> added a > comment.Fri, Jun 19, 3:09 AM > <https://developer.trustedfirmware.org/T763#9032> > > <https://developer.trustedfirmware.org/T763#> > > Hi, > > OK I understand a bit better, thanks for the details. > > Do you want me to post this query again on the TF-A mailing list? > > If it's not too much hassle for you then yes, I think it'd be preferable > to continue the discussion on the TF-A mailing list. I will withhold my > comments until then. > > > > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a >

5 years, 4 months

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Re: [TF-A] Unhandled Exception at EL3 in BL31 for Neoverse N1 with direct connect of DSU

by Witkowski, Andrzej

Sorry for a delay. I didn't have a bandwidth for doing it. I asked my teammate Marcin Salnik for testing the fix https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3493 on our Veloce emulator. Now, I can confirm that this fix works. ACC BL31 booted. From: Varun Wadekar <vwadekar(a)nvidia.com> Sent: Monday, June 01, 2020 8:57 PM To: Witkowski, Andrzej <andrzej.witkowski(a)intel.com> Cc: Lessnau, Adam <adam.lessnau(a)intel.com>; tf-a(a)lists.trustedfirmware.org Subject: RE: Unhandled Exception at EL3 in BL31 for Neoverse N1 with direct connect of DSU Hi, I believe the fix for this issue is part of https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3493. Can you please try that change? -Varun From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>> On Behalf Of Witkowski, Andrzej via TF-A Sent: Monday, June 1, 2020 7:08 AM To: tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org> Cc: Witkowski, Andrzej <andrzej.witkowski(a)intel.com<mailto:andrzej.witkowski@intel.com>>; Lessnau, Adam <adam.lessnau(a)intel.com<mailto:adam.lessnau@intel.com>> Subject: [TF-A] Unhandled Exception at EL3 in BL31 for Neoverse N1 with direct connect of DSU External email: Use caution opening links or attachments Hi, I work on project which uses ARM CPU Neoverse N1 with direct connect of DSU. I noticed the following error "Unhandled Exception at EL3" in BL31 bootloader after switching from ATF 2.1 to 2.2. The root cause is that after invoking neoverse_n1_errata-report function in lib/cpus/aarch64/neoverse_n1.S file and reaching the line 525, the function check_errata_dsu_934 in lib/cpus/aarch64/dsu_helpers.S file is always invoked regardless of whether ERRATA_DSU_936184 is set to 0 or to 1. In our case, ERRATA_DSU_936184 := 0. [cid:image001.png@01D64A40.BBEF1AA0] [cid:image002.png@01D64A40.BBEF1AA0] Neoverse N1 with direct connect version of DSU doesn't contain SCU/L3 cache and CLUSTERCFR_EL1 register. The error "Unhandled Exception at EL3" appears in BL31 bootloader during attempt to read the CLUSTERCFR_EL1 register which doesn't exist in our RTL HW. Andrzej Witkowskie Intel Technology Poland --------------------------------------------------------------------- Intel Technology Poland sp. z o.o. ul. Słowackiego 173 | 80-298 Gdańsk | Sąd Rejonowy Gdańsk Północ | VII Wydział Gospodarczy Krajowego Rejestru Sądowego - KRS 101882 | NIP 957-07-52-316 | Kapitał zakładowy 200.000 PLN. Ta wiadomość wraz z załącznikami jest przeznaczona dla określonego adresata i może zawierać informacje poufne. W razie przypadkowego otrzymania tej wiadomości, prosimy o powiadomienie nadawcy oraz trwałe jej usunięcie; jakiekolwiek przeglądanie lub rozpowszechnianie jest zabronione. This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by others is strictly prohibited. --------------------------------------------------------------------- Intel Technology Poland sp. z o.o. ul. Sowackiego 173 | 80-298 Gdask | Sd Rejonowy Gdask Pnoc | VII Wydzia Gospodarczy Krajowego Rejestru Sdowego - KRS 101882 | NIP 957-07-52-316 | Kapita zakadowy 200.000 PLN. Ta wiadomo wraz z zacznikami jest przeznaczona dla okrelonego adresata i moe zawiera informacje poufne. W razie przypadkowego otrzymania tej wiadomoci, prosimy o powiadomienie nadawcy oraz trwae jej usunicie; jakiekolwiek przegldanie lub rozpowszechnianie jest zabronione. This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by others is strictly prohibited.

5 years, 4 months

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Question on authenticating FIP images

by arm in-cloud

<Posting the question to tf-a mailing list from Maniphest and copied all previous conversation> Hi, On our boards I have an external security chip which communicates with AP (application processor) over a encrypted communication channel. I have a communication driver/PTA running in a Secure Playload (OPTEE) running in S-EL1. My firmware update workflow (FIP.BIN) is as below. In our design, we have QSPI from where AP boots up (regular TF-A workflow) this QSPI is also accessible from external Security chip (which is responsible for AP/SOC's firmware update) On software side, I have a Non-Secure application which receives the prebuilt binary (FIP.BIN) it chopps the binary in fixed sized buffers and send to OPTEE-PTA which internally sends the binary to Security chip (which then validates and writes to QSPI). Now in this firmware update flow, I want to do following things. 1. I want to validate/authenticate the FIP image before sending to security chip. If it authentication is successful only then send the image to security chip. This is what I am planning:- 1. Receive the whole FIP.BIN from NS-APP and store it in RAM (in OPTEE's RAM) 2. I am planning to implement a SIP service in TF-A which will receive the address and size of FIP.BIN in RAM. 3. Calls in to auth_mod driver for authentication of the image. I don't want to update the images immediately I just needs to authenticate the images within FIP.BIN To design this feature, I started looking in to BL1 & BL2 code but not sure how much piece if code I can reuse or use. Also I looked in to fwu test apps if I can mimic something but looks the fwu implementation is absolutely different. My question is how do I just use the authentication functionality available in TF-A for my purpose. Appreciate your help! sandrine-bailleux-arm <https://developer.trustedfirmware.org/p/sandrine-bailleux-arm/> added a subscriber: sandrine-bailleux-arm <https://developer.trustedfirmware.org/p/sandrine-bailleux-arm/>.Tue, Jun 16, 6:50 AM <https://developer.trustedfirmware.org/T763#9015> <https://developer.trustedfirmware.org/T763#> Hi, Apologies for the delay, I had missed this ticket... Generally speaking, it's better to post questions on the TF-A mailing list [1], it's got far better visibility than Maniphest (which few people monitor I believe) and you are more likely to get a quick answer there. First of all, I've got a few questions that would help me understand your design. 1. You say that OPTEE-PTA would store the FIP image in its RAM. I am assuming this is secure RAM, that only secure software can access, right? If not, this would not seem very secure to me, as the normal world software could easily change the FIP image after it has been authenticated and replace it with some malicious firmware. 1. You'd like to implement a SiP service in TF-A to authenticate the FIP image, given its base address and size. Now I am guessing this would be an address in OPTEE's RAM, right? 1. What cryptographic key would sign the FIP image? Would TF-A have access to this key to authenticate it? 1. What would need authentication? The FIP image as a monolithic blob, or each individual image within this FIP? And in the latter case, would all images be authenticated using the same key or would different images be signed with different keys? Now, coming back to where to look into TF-A source code. You're looking in the right place, all Trusted Boot code is indeed built into BL1 and BL2 in TF-A. The following two documents detail how the authentication framework and firmware update flow work in TF-A and are worth reading if you haven't done so already: https://trustedfirmware-a.readthedocs.io/en/latest/design/auth-framework.ht… https://trustedfirmware-a.readthedocs.io/en/latest/components/firmware-upda… I reckon you'd want to reuse the cryptographic module in your case. It provides a callback to verify the signature of some payload, see [2] and include/drivers/auth/crypto_mod.h. However, I expect it won't be straight forward to reuse this code outside of its context, as it expects DER-encoded data structures following a specific ASN.1 format. Typically when used in the TF-A trusted boot flow, these are coming from X.509 certificates, which already provide the data structures in the right format. Best regards, Sandrine Bailleux [1] https://lists.trustedfirmware.org/mailman/listinfo/tf-a [2] https://trustedfirmware-a.readthedocs.io/en/latest/design/auth-framework.ht… arm-in-cloud <https://developer.trustedfirmware.org/p/arm-in-cloud/> added a comment.Edited · Wed, Jun 17, 11:42 AM <https://developer.trustedfirmware.org/T763#9018> <https://developer.trustedfirmware.org/T763#> Thank you Sandrine for your feedback. Following are the answers to your questions: 1. Yes, the image will be stored in to OPTEEs secured memory. I am guessing TF-A gets access to this memory. 2. Yes, the OPTEE's secure memory address and Size will be passed to the SiP service running in TF-A. 3. These are RSA keys, in my case only TF-A has access to these keys. On a regular boot these are the same keys used to authenticate the images (BL31, BL32 & BL33) in the FIP stored in the QSPI. 4. Yes all images will be authenticated using same key. Thanks for the documentation links, from the firmware-update doc. I am mainly trying to use IMAGE_AUTH part. In my case COPY is already done just needs AUTH part and once AUTH is successful, optee will pass that payload the security chip for update. And after rebooting my device will boot with new firmware. (In my case we always reboot after firmware updates). Do you want me to post this query again on the TF-A mailing list? Thank you! sandrine-bailleux-arm <https://developer.trustedfirmware.org/p/sandrine-bailleux-arm/> added a comment.Fri, Jun 19, 3:09 AM <https://developer.trustedfirmware.org/T763#9032> <https://developer.trustedfirmware.org/T763#> Hi, OK I understand a bit better, thanks for the details. Do you want me to post this query again on the TF-A mailing list? If it's not too much hassle for you then yes, I think it'd be preferable to continue the discussion on the TF-A mailing list. I will withhold my comments until then.

5 years, 4 months

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Re: [TF-A] GICV3: system interface EOI ordering RFC

by Sandeep Tripathy

Hi Raghu, > -----Original Message----- > From: TF-A [mailto:tf-a-bounces@lists.trustedfirmware.org] On Behalf Of > Raghu Krishnamurthy via TF-A > Sent: Monday, June 08, 2020 7:09 PM > To: tf-a(a)lists.trustedfirmware.org > Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC > > Hello, > > Sorry for chiming in late. Are we sure that the msr/mrs to the GICv3 EOI > register is not a context synchronizing event or ensures ordering itself > ? Also did the addition of DSB() fix the issue ? If yes, can you try > adding a delay or a few NOP's/dummy instructions or an ISB to see if the > issue goes away? Yes these experiments were done to observe the behavior which led to this change. A definitive confirmation of how core treats these accesses can be only be from arm core team or by actually probing the transfers. I had a response from arm support on the very same question which reads as follows: "In theory, the memory barrier should be placed between the clearing of the peripheral and the access to the EOI register". In a slightly unrelated case I had observed this with NVIC on axi probe and there is no feasibility to repeat this with GICv3 at the moment. > > We need to know the right thing to do architecturally and confirm that > the issue is really due to reordering at the core before adding the DSB. > Adding a DSB might be masking a timing issue. Is the above response and what Soby had confirmed sufficient ? or could someone from arm get this reconfirmed from core design unless it is obvious to them ? And this is equally applicable to linux as well. > > -Raghu > Thanks Sandeep > > > On 6/8/20 4:47 AM, Sandeep Tripathy via TF-A wrote: > >> -----Original Message----- > >> From: Soby Mathew [mailto:Soby.Mathew@arm.com] > >> Sent: Monday, June 08, 2020 3:36 PM > >> To: Sandeep Tripathy; Olivier Deprez; tf-a(a)lists.trustedfirmware.org > >> Cc: nd > >> Subject: RE: [TF-A] GICV3: system interface EOI ordering RFC > >> > >> Just some inputs from my side: > >> I agree we need at least a dsb() after the write to MMIO region to > >> silence > >> the > >> peripheral and before the EOI at GIC sysreg interface. Adding it to the > >> GIC EOI > > > > Thanks for the confirmation. Now it’s about choosing the right place. > > > >> API seems the logical thing to do but as Olivier mentions, there are > >> interrupt > >> handler which do not deal with MMIO (eg: the Systimer interrupt) so > >> adding > >> it > >> to GICv3 API might be arduous for such handlers. > >> > >> So there is a choice here to let the interrupt handlers to deal with > >> ensuring > >> completeness before EOI at sysreg interface or adding it to GICv3 EOI > >> API > >> and > >> take the overhead for interrupt handlers which do not have to deal with > >> MMIO. > >> > > > > Yes I feel either of these is a must to guarantee functionality > > architecturally though > > both approach end up with some unnecessary overhead. > > > > If GICv3 api takes care then it is an overhead for some ISRs dealing > > with > > non-MMIO. > > At present I do not see an active use case in reference implementation > > where > > sys timer > > ISR is in a performance intensive path where one additional DSB will be > > perceivable. > > But there may be some I could be totally wrong in this assumption > (pmu/debug > > or.. not sure). > > Whereas I can certainly imagine some MMIO ISRs in performance critical > > path > > where unnecessary > > DSB is not acceptable at all. > > > > If the interrupt handler needs to ensure then it will generically add > > 'DSB' > > as I think > > the driver cannot and should not make assumptions about how EOI is done > > afterwards. > > That will be overhead for the ISRs dealing with MMIO peripherals and non > > GIC-v3. > > If we consider only GICv3+ then good. Otherwise I would prefer the > > 'plat_ic_end_of_interrupt' > > like Olivier mentioned with a #if GICv3 instead of each ISRs dealing > > with > > it. > > > >> The GICv3 legacy MMIO CPU interface is deprecated for TF-A and the sys > >> interface is the only one GICv3 driver in TF-A supports. > > > > Right we can ignore the GICv3 legacy mode but GICv2 will still remain ? > > > >> > >> Best Regards > >> Soby Mathew > >> > > > > Thanks > > Sandeep > > > >>> -----Original Message----- > >>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of > Sandeep > >>> Tripathy via TF-A > >>> Sent: 08 June 2020 10:34 > >>> To: Olivier Deprez <Olivier.Deprez(a)arm.com>; tf- > >> a(a)lists.trustedfirmware.org > >>> Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC > >>> > >>> Hi Olivier, > >>>> -----Original Message----- > >>>> From: Olivier Deprez [mailto:Olivier.Deprez@arm.com] > >>>> Sent: Monday, June 08, 2020 1:14 PM > >>>> To: tf-a(a)lists.trustedfirmware.org; Sandeep Tripathy > >>>> Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC > >>>> > >>>> Hi Sandeep, > >>>> > >>>> gicv3_end_of_interrupt_sel1 is a static access helper macro. Its > >>>> naming precisely tells what it does at gicv3 module level. It is > >>>> called from > >>> the weak > >>>> plat_ic_end_of_interrupt function for BL32 image. > >>>> > >>>> I tend to think it is the driver responsibility to ensure the module > >>> interrupt > >>>> acknowledge register write is reaching HW in order (or "be visible to > >>> all > >>>> observers"). > >>> > >>> The driver should be agnostic of what interrupt controller is used and > >>> its > >>> behavior. > >>> And since 'all' writes were to mmio ranges mapped Device(nGnRE) > >>> /strongly-ordered(nGnRnE) > >>> there was no such need. This is a special case for GICv3 system > >>> interface only. > >>> Adding at driver level a DSB is unnecessary for other interrupt > >>> controllers. > >>> > >>>> Also I suspect adding a dsb might not be required generically for all > >>> kind of IP. > >>> > >>> Here are you referring to the peripheral IP or interrupt controller IP > >>> ? > >>> The issue is reordering at arm core itself (STR to device address Vs > >>> msr(sysreg > >>> write)). > >>> So I think Its applicable for all IP. > >>> > >>>> Adding a barrier in generic code might incur an unnecessary > >>>> bottleneck. > >>> > >>> But if there is a need to *ensure* presence of at least one DSB > >>> between > >>> the > >>> write transfer from core to device clear and gicv3 eoi icc register > >>> write in a > >>> generic way then what other option we have. > >>>> > >>>> Thus wouldn't it be better to add the barrier to the overridden > >>>> platform function rather than in generic gicv3 code? > >>> > >>> That can be done but I feel this is more to do with gicv3 system > >>> interface only. > >>> Inside plat_xxx one has to check #if GICV3 ...and system interface. > >>>> > >>>> I have a put a comment in the review, we can continue the discussion > >>> there. > >>>> > >>>> Regards, > >>>> Olivier. > >>>> > >>> Thanks > >>> Sandeep > >>>> ________________________________________ > >>>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of > >>>> Sandeep Tripathy via TF-A <tf-a(a)lists.trustedfirmware.org> > >>>> Sent: 05 June 2020 19:43 > >>>> To: tf-a(a)lists.trustedfirmware.org > >>>> Subject: [TF-A] GICV3: system interface EOI ordering RFC > >>>> > >>>> Hi, > >>>> In a typical interrupt handling sequence we do 1-Read IAR > >>>> 2-Do interrupt handling > >>>> 3-Clear the interrupt at source , so that the device de-asserts > >>>> IRQ > >>> request to > >>>> GIC > >>>> >> I am suggesting a need of DSB here in case of GICv3 +. > >>>> 4-Write to GIC cpu interface to do EOI. > >>>> > >>>> Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write > >>>> over > >>> AMBA > >>>> interface. The > >>>> Addresses are mapped with (nR) attribute. Hence the write transfers > >>> from the > >>>> core will be > >>>> generated at step 3 and 4 in order. Please ignore the additional > >>> buffers/bridges > >>>> in path from > >>>> core till peripheral which has to be dealt separately as per SOC. > >>>> > >>>> Query: I understand GICv3 system interface accesses are not over > >>>> this > >>> protocol > >>>> and core will not > >>>> follow the ordering rule ? > >>>> > >>>> I have observed spurious interrupt issue/manifestation ( I don't have > >>> the > >>>> transfers probed) in > >>>> RTOS environment where I have a primitive GICv3 driver but I wonder > >>>> why things does not fail in Linux or tf-a. If it is working because > >>>> from step(3) to > >>> step(4) we have > >>>> barriers by chace > >>>> due to other device register writes then I would suggest to have one > >>>> in > >>> the EOI > >>>> clearing API itself. > >>>> > >>>> RFC: > >>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454 > >>>> > >>>> Thanks > >>>> Sandeep > >>> -- > >>> TF-A mailing list > >>> TF-A(a)lists.trustedfirmware.org > >>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] Upgrading libfdt library

by Joanna Farley

I think it is clear Madhu has been applying due diligence here both in his own testing and notification to the project through the ML so that consumers can respond and also perform any testing they feel is necessary. In think its appropriate for us to pause while we wait for such feedback but it would be good to have some indication on who feels there might be an issue here and wants to provide feedback. I appreciate you are Varun and we need to analyse the risks and what mitigations need to be in place. As you may have picked up on from the various tech forums we take testing seriously and are looking to augment with different test strategies and tools however these will take time to deploy and spread their coverage through the project codebase. Until then we will have to analyse the level of risk and apply the appropriate level of mitigations which I think Madhu has but lets see if we have some specific issues needing further mitigations to give more confidence. Thanks Joanna On 19/06/2020, 23:35, "TF-A on behalf of Varun Wadekar via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Hi, Thanks for the information. Adding libfdt to the unit testing framework is a good idea. The verification should give us more confidence on the stability side. Let’s see if platform owners would like to include more tests. -Varun -----Original Message----- From: Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com> Sent: Friday, June 19, 2020 1:01 PM To: Varun Wadekar <vwadekar(a)nvidia.com> Cc: tf-a(a)lists.trustedfirmware.org Subject: RE: [TF-A] Upgrading libfdt library External email: Use caution opening links or attachments Hi Varun I tested the patch by running all applicable tf-a-tests suites [1] and Linux boot tests on FVP and Juno platforms. Since libfdt is platform agnostic, we are planning on adding it to the unit test framework as well(which was described in yesterday's tech forum). I need to admit that I am (over!) confident about libfdt since it is also used in U-boot and Linux projects. It seems the release tags don’t have much significance in the dtc project. Hence, I picked the latest commit at the time. In our internal CI, we also run Coverity MISRA and other static checks to find issues in TF-A and fix them as needed. However, we don’t fix issues reported in 3rd party libraries such as libfdt. I am waiting to hear feedback from various platform owners if they have any issues with this upgrade. [1] https://git.trustedfirmware.org/TF-A/tf-a-tests.git/tree/tftf/tests Thanks, Madhukar -----Original Message----- From: Varun Wadekar <vwadekar(a)nvidia.com> Sent: Thursday, June 18, 2020 1:30 PM To: Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com> Cc: tf-a(a)lists.trustedfirmware.org Subject: RE: [TF-A] Upgrading libfdt library Hi, I think there are some valid concerns raised in the thread. Since this is an external project I felt we needed to set a criteria for the upgrade. One day, when we start using the unit testing framework and have 100% coverage numbers and solid positive/negative testing, we would be more confident. Until then we just have to live with what have. @Madhukar is there any we can find out all the tests, static analysis checks, security checks that was run on the upgrade? Just trying to understand how confident we are that this does not introduce any regressions? -Varun -----Original Message----- From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghu K via TF-A Sent: Thursday, June 18, 2020 9:07 AM To: tf-a(a)lists.trustedfirmware.org Subject: Re: [TF-A] Upgrading libfdt library External email: Use caution opening links or attachments One thing that might be worth considering is versioning the library like xlat_tables and xlat_tables_v2 for a few releases and deprecate the old one if/when there is broad agreement from platforms to move to the new one. Platforms can perform their independent testing like STM and can report back over time. Obviously, for those few releases if there are API changes in libfdt there will have to be support for both new and old api's which will cause temporary ugliness but this might ease concerns about testing, stability etc. -Raghu On 6/18/20 4:12 AM, Soby Mathew via TF-A wrote: >> -----Original Message----- >> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of >> Sandrine Bailleux via TF-A >> Sent: 16 June 2020 13:09 >> To: Alexei Fedorov <Alexei.Fedorov(a)arm.com>; Madhukar Pappireddy >> <Madhukar.Pappireddy(a)arm.com>; Varun Wadekar <vwadekar(a)nvidia.com> >> Cc: tf-a(a)lists.trustedfirmware.org >> Subject: Re: [TF-A] Upgrading libfdt library >> >> Hi Alexei, >> >> On 6/16/20 1:51 PM, Alexei Fedorov wrote: >>> Thanks for your very detailed explanation of the reason behind this >>> solution. >>> This brings the question on how do we monitor libfdt bug fixes, code >>> cleanup, etc. (which Madhukar pointed out) and integrate these >>> changes in TF-A source tree. >> Right now, it is a manual process and not only for libfdt but for all >> projects TF-A depends on. We keep an eye on them and aim at updating >> them when necessary. Unfortunately, like any manual process, it is >> error-prone and things might slip through the cracks. The TF-A >> release tick is usually a good reminder to update all dependencies >> but unfortunately libfdt has been left behind for some time (about 2 years)... > As I recall, when we tried to update libfdt last time, there was significant code bloat in generated binary (feature creep?) and we abandoned the update. The policy was to stick to a stable version and only update if there are any bugfixes or new feature we would want to make use of. > > Generally speaking, we might have done several fixes in the imported 3rd party library by running static checks like for MISRA compliance etc and this has to be repeated when the library is updated. Also, for security audits, it is important to be sure of the "security status" of the imported library and hence we tended to not update for every release. > > But I agree that we do have to be on top of bug fixes and hence we need to update but not sure how we can balance this with concerns above. > > Regarding MbedTLS, being a security critical project, we would like to encourage platform integrators to take ownership of staying upto date rather than relying on update from TF-A repo. Hence the motivation to keep it separate. > > Best Regards > Soby Mathew > > > > >> Regards, >> Sandrine >> -- >> TF-A mailing list >> TF-A(a)lists.trustedfirmware.org >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

1
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Re: [TF-A] Upgrading libfdt library

by Varun Wadekar

Hi, I think there are some valid concerns raised in the thread. Since this is an external project I felt we needed to set a criteria for the upgrade. One day, when we start using the unit testing framework and have 100% coverage numbers and solid positive/negative testing, we would be more confident. Until then we just have to live with what have. @Madhukar is there any we can find out all the tests, static analysis checks, security checks that was run on the upgrade? Just trying to understand how confident we are that this does not introduce any regressions? -Varun -----Original Message----- From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghu K via TF-A Sent: Thursday, June 18, 2020 9:07 AM To: tf-a(a)lists.trustedfirmware.org Subject: Re: [TF-A] Upgrading libfdt library External email: Use caution opening links or attachments One thing that might be worth considering is versioning the library like xlat_tables and xlat_tables_v2 for a few releases and deprecate the old one if/when there is broad agreement from platforms to move to the new one. Platforms can perform their independent testing like STM and can report back over time. Obviously, for those few releases if there are API changes in libfdt there will have to be support for both new and old api's which will cause temporary ugliness but this might ease concerns about testing, stability etc. -Raghu On 6/18/20 4:12 AM, Soby Mathew via TF-A wrote: >> -----Original Message----- >> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of >> Sandrine Bailleux via TF-A >> Sent: 16 June 2020 13:09 >> To: Alexei Fedorov <Alexei.Fedorov(a)arm.com>; Madhukar Pappireddy >> <Madhukar.Pappireddy(a)arm.com>; Varun Wadekar <vwadekar(a)nvidia.com> >> Cc: tf-a(a)lists.trustedfirmware.org >> Subject: Re: [TF-A] Upgrading libfdt library >> >> Hi Alexei, >> >> On 6/16/20 1:51 PM, Alexei Fedorov wrote: >>> Thanks for your very detailed explanation of the reason behind this >>> solution. >>> This brings the question on how do we monitor libfdt bug fixes, code >>> cleanup, etc. (which Madhukar pointed out) and integrate these >>> changes in TF-A source tree. >> Right now, it is a manual process and not only for libfdt but for all >> projects TF-A depends on. We keep an eye on them and aim at updating >> them when necessary. Unfortunately, like any manual process, it is >> error-prone and things might slip through the cracks. The TF-A >> release tick is usually a good reminder to update all dependencies >> but unfortunately libfdt has been left behind for some time (about 2 years)... > As I recall, when we tried to update libfdt last time, there was significant code bloat in generated binary (feature creep?) and we abandoned the update. The policy was to stick to a stable version and only update if there are any bugfixes or new feature we would want to make use of. > > Generally speaking, we might have done several fixes in the imported 3rd party library by running static checks like for MISRA compliance etc and this has to be repeated when the library is updated. Also, for security audits, it is important to be sure of the "security status" of the imported library and hence we tended to not update for every release. > > But I agree that we do have to be on top of bug fixes and hence we need to update but not sure how we can balance this with concerns above. > > Regarding MbedTLS, being a security critical project, we would like to encourage platform integrators to take ownership of staying upto date rather than relying on update from TF-A repo. Hence the motivation to keep it separate. > > Best Regards > Soby Mathew > > > > >> Regards, >> Sandrine >> -- >> TF-A mailing list >> TF-A(a)lists.trustedfirmware.org >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

2
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How should we manage patches affecting multiple users?

by Sandrine Bailleux

Hello everyone, I would like to start a discussion around the way we want to handle changes that affect all platforms/users. This subject came up in this code review [1]. I'll present my views on the subject and would like to know what others think. First of all, what do we mean by "changes that affect all platforms"? It would be any change that is not self-contained within a platform port. IOW, a change in some file outside of the plat/ directory. It could be in a driver, in a library, in the build system, in the platform interfaces called by the generic code... the list goes on. 1. Some are just implementation changes, they leave the interfaces unchanged. These do not break other platforms builds since the call sites don't need to be updated. However, they potentially change the responsibilities of the interface, in which case this might introduce behavioral changes that all users of the interface need to be aware of and adapt their code to. 2. Some other changes might introduce optional improvements. They introduce a new way of doing things, perhaps a cleaner or more efficient one. Users can safely stay with the old way of doing things without fear of breakage but they would benefit from migrating. This is the case of Alexei's patch [1], which introduces an intermediate GICv2 makefile, that Arm platforms now include instead of pulling each individual file by themselves. At this point, it is just an improvement that introduces an indirection level in the build system. This is an improvement in terms of maintainability because if we add a new essential file to this driver in the future, we'll just need to add it in this new GICv2 makefile without having to update all platforms makefiles. However, platform makefiles can continue to pull in individual files if they wish to. 3. Some other changes might break backwards compatibility. This is something we should avoid as much as possible and we should always strive to provide a migration path. But there are cases where there might be no other way than to break things. In this case, all users have to be migrated. Now the question we were pondering in Gerrit is, where does the responsibility of migrating all platforms/users lie for all these types of changes? Is the patch author responsible to do all the work? I think it's hard to come up with a one-size-fits-all answer. It really depends on the nature of changes, their consequences, the amount of work needed to do the migration, the ability for the patch author to test these changes, to name a few. I believe the patch author should migrate all users on a best-effort basis. If it's manageable then they should do the work and propose a patch to all affected users for them to review and test on their platforms. On the other hand, if it's too much work or impractical, then I think the best approach would be for the patch author to announce and discuss the changes on this mailing list. In some scenarios, the changes might be controversial and not all platform owners might agree that the patch brings enough benefit compared to the migration effort, in which case the changes might have to be withdrawn or re-thought. In any case, I believe communication is key here and no one should take any unilateral decision on their own if it affects other users. I realize this is a vast subject and that we probably won't come up with an answer/reach an agreement on all the aspects of the question. But I'd be interested in hearing other contributors' view and if they've got any experience managing these kinds of issues, perhaps in other open source project. Best regards, Sandrine [1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4538

5 years, 4 months

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Re: [TF-A] ATF LTS version

by Varun Wadekar

Hello Joanna, I had discussed the idea with Matteo in the past, but the discussion in the last tech forum prompted the email. >> I appreciate this CI is currently a little opaque to many contributors as this is still in the process of being transitioned to the OpenCI hosted by Trustedfirmware.org servers which will be visible to all I agree, it is hard to test all the use cases. The opaque nature of the CI is a bit annoying, but not a big issue. >> the additional testing done for a 6 monthly tagged release is quite minimal and the larger work is ensuring all documentation is up to date. Additionally all new features are generally behind their own build flags but I appreciate it is some work for a tagged release to be absorbed into product offerings. Interesting In one of our internal discussions we were exploring the possibility of using doxygen style comments and creating an API reference for a release without a lot of effort. We should try to explore this idea in the community. >> One thing that had been considered briefly was the production of a security bug only branch That is a good idea and can act as the base for the LTS version. But we should consider increasing the scope and include bug fixes, stability issues, performance issues, etc. I believe when the community widely adopts TFTF and starts upstreaming the test cases, we can expect more interest around a LTS release. For platform owners (e.g. NVIDIA) it makes sense to plan our release strategy around LTS versions. Right now, our releases lack direction as we don’t know which version to use. And then there is additional pain of rebasing recent fixes/improvements on older releases. -Varun -----Original Message----- From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Joanna Farley via TF-A Sent: Thursday, June 11, 2020 6:47 AM To: Matteo Carlini <Matteo.Carlini(a)arm.com>; tf-a(a)lists.trustedfirmware.org Subject: Re: [TF-A] ATF LTS version External email: Use caution opening links or attachments Hi Varun, I guess this suggestion came in response to last weeks Tech Forum discussion from a question about experiences people had from migrating to different TF-A tagged releases. In general we try and keep the tip of Master at tagged release quality through an extensive CI system ran on each patch. I appreciate this CI is currently a little opaque to many contributors as this is still in the process of being transitioned to the OpenCI hosted by Trustedfirmware.org servers which will be visible to all. As mentioned in the recent "Overview of the TF-A v2.3 Release" presentation on https://www.trustedfirmware.org/meetings/tf-a-technical-forum/ the additional testing done for a 6 monthly tagged release is quite minimal and the larger work is ensuring all documentation is up to date. Additionally all new features are generally behind their own build flags but I appreciate it is some work for a tagged release to be absorbed into product offerings. I asked at the tech forum last week what more we could do to allow releases to be integrated more easily. On the call it was requested if we could disable weak bindings to symbols so it could be more easily seen where platform decisions may need to be made and we will look into this. If there are any more adjustments to the way tagged releases are produced please let us know. One thing that had been considered briefly was the production of a security bug only branch that was maintained only between 6 month tagged releases before being replaced by the next security bug only branch based on the next 6 month release but that has not progressed very far as a proposal as until your email here it was perceived to not be in demand. A LTS branch is a larger endeavour as it sounds like something that includes more than security fixes and I look forward to you elaborating more as Matteo requests. Thanks Joanna On 11/06/2020, 12:19, "Matteo Carlini via TF-A" <tf-a(a)lists.trustedfirmware.org> wrote: Hi Varun, Thanks for raising this topic (but please do embrace the official terminology “TF-A”…we never really promoted ATF and it's also absolutely outdated now 😉 ). Arm has received different queries over time on supporting Trusted Firmware LTS releases, but the effort to sustain them is something that the Arm engineering team alone cannot really afford and commit to (either in the TF-A or TF-M space). The idea has also been just raised to the Trusted Firmware project Board for initial consideration and we will be all very keen to understand how much interest there is from the wider TF-A community of adopters and external (non-Arm) maintainers, so to evaluate the possibility of a more concrete proposal to be carried on within the community Project. I guess it will also be good to start by elaborating more concretely on the requirements that you would like to see in an hypothetical LTS versioning scheme. Thanks Matteo > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A > Sent: 10 June 2020 22:47 > To: tf-a(a)lists.trustedfirmware.org > Subject: [TF-A] ATF LTS version > > Hello team, > > To extend the discussion around version upgrades from our last call, I would like to understand if there is enough interest around generating a LTS version of the TF-A to alleviate the pain. > > For NVIDIA, this would be helpful as it streamlines the upgrade path for our devices in the field. The LTS version will guarantee security fixes, bug fixes, stability fixes for the longer term and we won’t have to upgrade the entire firmware to get these goodies. > > It would be interesting to see what OEMs and maintainers think about this? Has this been discussed at tf.org or Arm internally? > > -Varun -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

2
3
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Re: [TF-A] Upgrading libfdt library

by Raghu K

One thing that might be worth considering is versioning the library like xlat_tables and xlat_tables_v2 for a few releases and deprecate the old one if/when there is broad agreement from platforms to move to the new one. Platforms can perform their independent testing like STM and can report back over time. Obviously, for those few releases if there are API changes in libfdt there will have to be support for both new and old api's which will cause temporary ugliness but this might ease concerns about testing, stability etc. -Raghu On 6/18/20 4:12 AM, Soby Mathew via TF-A wrote: >> -----Original Message----- >> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandrine >> Bailleux via TF-A >> Sent: 16 June 2020 13:09 >> To: Alexei Fedorov <Alexei.Fedorov(a)arm.com>; Madhukar Pappireddy >> <Madhukar.Pappireddy(a)arm.com>; Varun Wadekar <vwadekar(a)nvidia.com> >> Cc: tf-a(a)lists.trustedfirmware.org >> Subject: Re: [TF-A] Upgrading libfdt library >> >> Hi Alexei, >> >> On 6/16/20 1:51 PM, Alexei Fedorov wrote: >>> Thanks for your very detailed explanation of the reason behind this >>> solution. >>> This brings the question on how do we monitor libfdt bug fixes, code >>> cleanup, etc. (which Madhukar pointed out) and integrate these changes >>> in TF-A source tree. >> Right now, it is a manual process and not only for libfdt but for all projects TF-A >> depends on. We keep an eye on them and aim at updating them when >> necessary. Unfortunately, like any manual process, it is error-prone and things >> might slip through the cracks. The TF-A release tick is usually a good reminder >> to update all dependencies but unfortunately libfdt has been left behind for >> some time (about 2 years)... > As I recall, when we tried to update libfdt last time, there was significant code bloat in generated binary (feature creep?) and we abandoned the update. The policy was to stick to a stable version and only update if there are any bugfixes or new feature we would want to make use of. > > Generally speaking, we might have done several fixes in the imported 3rd party library by running static checks like for MISRA compliance etc and this has to be repeated when the library is updated. Also, for security audits, it is important to be sure of the "security status" of the imported library and hence we tended to not update for every release. > > But I agree that we do have to be on top of bug fixes and hence we need to update but not sure how we can balance this with concerns above. > > Regarding MbedTLS, being a security critical project, we would like to encourage platform integrators to take ownership of staying upto date rather than relying on update from TF-A repo. Hence the motivation to keep it separate. > > Best Regards > Soby Mathew > > > > >> Regards, >> Sandrine >> -- >> TF-A mailing list >> TF-A(a)lists.trustedfirmware.org >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

1
0
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Re: [TF-A] Upgrading libfdt library

by Soby Mathew

> -----Original Message----- > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandrine > Bailleux via TF-A > Sent: 16 June 2020 13:09 > To: Alexei Fedorov <Alexei.Fedorov(a)arm.com>; Madhukar Pappireddy > <Madhukar.Pappireddy(a)arm.com>; Varun Wadekar <vwadekar(a)nvidia.com> > Cc: tf-a(a)lists.trustedfirmware.org > Subject: Re: [TF-A] Upgrading libfdt library > > Hi Alexei, > > On 6/16/20 1:51 PM, Alexei Fedorov wrote: > > Thanks for your very detailed explanation of the reason behind this > > solution. > > This brings the question on how do we monitor libfdt bug fixes, code > > cleanup, etc. (which Madhukar pointed out) and integrate these changes > > in TF-A source tree. > > Right now, it is a manual process and not only for libfdt but for all projects TF-A > depends on. We keep an eye on them and aim at updating them when > necessary. Unfortunately, like any manual process, it is error-prone and things > might slip through the cracks. The TF-A release tick is usually a good reminder > to update all dependencies but unfortunately libfdt has been left behind for > some time (about 2 years)... As I recall, when we tried to update libfdt last time, there was significant code bloat in generated binary (feature creep?) and we abandoned the update. The policy was to stick to a stable version and only update if there are any bugfixes or new feature we would want to make use of. Generally speaking, we might have done several fixes in the imported 3rd party library by running static checks like for MISRA compliance etc and this has to be repeated when the library is updated. Also, for security audits, it is important to be sure of the "security status" of the imported library and hence we tended to not update for every release. But I agree that we do have to be on top of bug fixes and hence we need to update but not sure how we can balance this with concerns above. Regarding MbedTLS, being a security critical project, we would like to encourage platform integrators to take ownership of staying upto date rather than relying on update from TF-A repo. Hence the motivation to keep it separate. Best Regards Soby Mathew > > Regards, > Sandrine > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

1
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Re: [TF-A] Upgrading libfdt library

by Yann GAUTIER

Hi, I've tested the libfdt update on STM32MP1. I can see a boot time increase by ~6%, thanks to U-Boot 'bootstage report' command. But I don't think this should block the lib upgrade. I've some comments about the patch, I'll send that on gerrit. Regards, Yann On 6/17/20 1:03 AM, Madhukar Pappireddy via TF-A wrote: > Hi Varun, > > I have pushed the draft patch here [1] to upgrade the libfdt source > files. I have tested this patch by running all tests that we usually run > before merging a patch to TF-A repo. I am looking forward to receiving > feedback from platform owners. > > However, I am not convinced why this effort needs an exhaustive > evaluation with various criteria as you mentioned below. I am upgrading > source files and I am not introducing a new project to TF-A. Let me know > your thoughts. > > [1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4596 > > Thanks, > > Madhukar > > *From:* Varun Wadekar <vwadekar(a)nvidia.com> > *Sent:* Monday, June 15, 2020 2:12 PM > *To:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com> > *Cc:* tf-a(a)lists.trustedfirmware.org > *Subject:* RE: Upgrading libfdt library > > Thanks, Madhukar. > > I think this needs a broader discussion where we form a list evaluation > criteria of features, API, metrics, KPIs etc by pooling them from the > platform owners. > > If we don’t receive any inputs, then it makes sense to execute the > current tests and make sure that they work as expected. > > Thoughts? > > -Varun > > *From:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com > <mailto:Madhukar.Pappireddy@arm.com>> > *Sent:* Monday, June 15, 2020 8:30 AM > *To:* Varun Wadekar <vwadekar(a)nvidia.com <mailto:vwadekar@nvidia.com>> > *Cc:* tf-a(a)lists.trustedfirmware.org <mailto:tf-a@lists.trustedfirmware.org> > *Subject:* RE: Upgrading libfdt library > > *External email: Use caution opening links or attachments* > > Hi Varun, > > Please find my replies inline. > > Thanks, > > Madhu > > *From:* Varun Wadekar <vwadekar(a)nvidia.com <mailto:vwadekar@nvidia.com>> > *Sent:* Friday, June 12, 2020 7:04 PM > *To:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com > <mailto:Madhukar.Pappireddy@arm.com>> > *Cc:* tf-a(a)lists.trustedfirmware.org <mailto:tf-a@lists.trustedfirmware.org> > *Subject:* RE: Upgrading libfdt library > > Hi Madhukar, > > Before we merge this change, can you please explain how we arrived at > this specific version? Are we tracking the stable version of the library? > > >> I was told by Andre that the releases(tags) by themselves don’t mean > much in the libfdt project and it is better to upgrade directly to the > recent commit(the latest HEAD was 85e5d83 when I started this > investigation). > > What would be the testing criteria before merging the library? Does tftf > provide any tests that can act as a smoking gun? > > >> Given that we rely more on libfdt APIs now, I plan to run all the > existing tests in our CI (includes tftf and Linux boot tests) to verify > if the libfdt library has any issues when integrating with TF-A. I > believe these tests are thorough enough. > > Does it make sense to ask platform owners to test the specific version > you plan to merge? This way we would have more confidence in the library. > > >> Yes, I wanted to take the feedback from platform owners and hence I > sent this email before actually pushing the patch to tf.org for review. > There was a performance concern in the past when upgrading libfdt source > files [1]. > > [1] https://github.com/ARM-software/tf-issues/issues/643 > > -Varun > > *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org > <mailto:tf-a-bounces@lists.trustedfirmware.org>> *On Behalf Of *Madhukar > Pappireddy via TF-A > *Sent:* Friday, June 12, 2020 4:48 PM > *To:* tf-a(a)lists.trustedfirmware.org <mailto:tf-a@lists.trustedfirmware.org> > *Subject:* [TF-A] Upgrading libfdt library > > *External email: Use caution opening links or attachments* > > Hello, > > I am planning to upgrade libfdt library source files in TF-A. They > haven’t been updated for a while. As the project moves towards improving > the fconf framework and adding more properties in device tree source > files, we rely more on libfdt APIs. I have done some preliminary > investigation to check if there is any performance penalty in upgrading > the libfdt source files integrated into TF-A from the current > version(which corresponds to commit aadd0b6 in the dtc repo [1]) to > master commit (85e5d83). I have run some basics tests on both x86 and > aarch64 machines and I have not seen any performance degradation. I plan > to push a patch shortly to integrate the latest version of libfdt files > in TF-A. > > Please let me know if you are aware of any performance issues or have > other concerns. > > [1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git > > Thanks, > > Madhu >

5 years, 4 months

1
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Re: [TF-A] Upgrading libfdt library

by Varun Wadekar

Hi Madhukar, Before we merge this change, can you please explain how we arrived at this specific version? Are we tracking the stable version of the library? What would be the testing criteria before merging the library? Does tftf provide any tests that can act as a smoking gun? Does it make sense to ask platform owners to test the specific version you plan to merge? This way we would have more confidence in the library. -Varun From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Madhukar Pappireddy via TF-A Sent: Friday, June 12, 2020 4:48 PM To: tf-a(a)lists.trustedfirmware.org Subject: [TF-A] Upgrading libfdt library External email: Use caution opening links or attachments Hello, I am planning to upgrade libfdt library source files in TF-A. They haven't been updated for a while. As the project moves towards improving the fconf framework and adding more properties in device tree source files, we rely more on libfdt APIs. I have done some preliminary investigation to check if there is any performance penalty in upgrading the libfdt source files integrated into TF-A from the current version(which corresponds to commit aadd0b6 in the dtc repo [1]) to master commit (85e5d83). I have run some basics tests on both x86 and aarch64 machines and I have not seen any performance degradation. I plan to push a patch shortly to integrate the latest version of libfdt files in TF-A. Please let me know if you are aware of any performance issues or have other concerns. [1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git Thanks, Madhu

5 years, 4 months

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Re: [TF-A] Upgrading libfdt library

by Sandrine Bailleux

Hi Alexei, On 6/15/20 2:18 PM, Alexei Fedorov via TF-A wrote: > I'm wondering why we need to integrate libfdt sources in TF-A? Why > cannot we use the same option as for MbedTls when the build system gets > the path to the preloaded source tree? As far as I know, the question is the other way around: why is mbed TLS not integrated in the TF-A source tree? If you look at the other external libraries used by TF-A (not just libfdt, but also compiler-rt library, zlib, ...), they all are integrated. As far as I am aware, there are several reasons for keeping these projects in the TF-A tree: 1) It is more developer-friendly. Whenever you clone the TF-A repo, you get all required dependencies at the same time, no need to pull them yourself. 2) It allows us to keep local modifications on top of mainline. Such modifications are sometimes necessary or make our life easier to integrate/interface the project with the rest of the TF-A code base. 3) We don't depend on the library project infrastructure. For example if their git server is down, this would not affect us, as we've got our own copy hosted on tf.org. Not sure this third reason was actually considered at the time the decision was made but I see this as a tiny bonus. Now 1) could be achieved some other way, for example we could add the dependent projects as git submodules and have a setup script that pulls them in. We did not go for this option at the time and I don't recall exactly why. It might just be because of the infrastructure/setup required to work with git submodules. So having these projects integrated in the TF-A source tree is the common practice in our project. As far as I am aware, the reason why we treat mbed TLS differently is because it is very security sensitive, thus it's important that people keep up to date with the latest version to get all latest vulnerability fixes. If we had imported it in the TF-A project, this would have put the onus on us to monitor mbed TLS for security fixes and push updates as soon as they become available. This was deemed impractical and too much responsibility for us at the time. Regards, Sandrine

5 years, 4 months

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Announcing one new maintainer for the TF-A project

by Sandrine Bailleux

Hello all, I am glad to announce that Raghu Krishnamurthy has been appointed maintainer for the TF-A project. The maintainers list has been updated accordingly in the following patch: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4582 Best regards, Sandrine

5 years, 4 months

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Re: [TF-A] fconf: Validating config data

by Madhukar Pappireddy

Hi Raghu, We had a discussion internally about handling the mandatory and optional properties in fconf and we believe we can use the following approach. Please let us know if it is acceptable to you. As agreed over the mailing list, we treat the scenarios of a missing/incorrect mandatory property or a structurally bad dtb as an integration error and must lead to panic in runtime. It is the responsibility of the developer providing the populate callback to detect and return an error code in such scenarios. It will be treated as an unrecoverable error and further escalated to panic() by the fconf framework itself. An incorrect or missing optional property in a dtb should lead to a warning message and the boot loader should continue after assigning a default value to the specific property. Further, every property accessed by a populate callback should be clearly defined as either mandatory or optional in a fconf based binding document such as the one shown here [1]. This must be enforced in spirit as part of the code review process. We believe the callbacks can be categorized into two: Generic vs platform-specific. Generic callbacks are the ones that are required to support a standard component supported by platforms running TF-A such as TBBR, SDEI, IO Policy, GICv3, etc. Platform-specific callbacks are provided by platform developers to work with non-standard components such as a Proprietary Hardware IP. The binding document for generic populate callbacks should be provided by the TF-A project. The generic binding will become a contract for the platforms to implement the support for integrating standard components and hence, will be platform agnostic. Correspondingly, it is the responsibility of the platform developer to provide the binding for platform-specific populate callbacks. Any thoughts? [1] https://trustedfirmware-a.readthedocs.io/en/latest/components/fconf/fconf_p… Thanks, Madhukar -----Original Message----- From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Manish Badarkhe via TF-A Sent: Wednesday, May 20, 2020 6:00 AM To: Raghu K <raghu.ncstate(a)icloud.com>; Sandrine Bailleux <Sandrine.Bailleux(a)arm.com>; tf-a(a)lists.trustedfirmware.org; Louis Mayencourt <Louis.Mayencourt(a)arm.com> Cc: nd <nd(a)arm.com> Subject: Re: [TF-A] fconf: Validating config data Hi Raghu We have plan to work on this and come up with some design which handles mandatory/critical properties. On 13/05/2020, 22:18, "TF-A on behalf of Raghu K via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Hi All, Since the 2.3 release is done, can we revisit this topic? I think we left this with finalizing on how to handle bad/incorrect DTB's. Sandrine's latest proposal below: "A bad DTB seems more like an integration error than a programming error to me, and thus should be handled with runtime checks according to the current guidelines. Incorrect values for mandatory properties should probably be treated as unrecoverable errors (causing a panic) and incorrect/missing optional properties as recoverable errors (issuing a warning message)." I agree with this proposal and think we should follow this. This addresses my original concern of handling errors consistently and being safe by verifying mandatory/critical properties at run-time. Thoughts ? Thanks Raghu On 4/13/20 10:27 AM, Raghu Krishnamurthy wrote: > Thanks Sandrine. Revisiting after v2.3 is sounds fine. > > -Raghu > > On 4/10/20 2:25 AM, Sandrine Bailleux wrote: >> Hi Raghu, >> >> On 4/8/20 12:50 AM, Raghu Krishnamurthy wrote: >>> Thanks Sandrine, Louis, >>> >>> Agree with both of you. I'm fine with using asserts or panics, as >>> long as we uniformly use it. The change i sent out(review 3845) was >>> because i noticed inconsistency in handling errors. If we do use >>> asserts, all code that checks for mandatory properties, should be >>> changed to assert as opposed to return error code. For optional >>> properties, we can continue to return an error code or print >>> warnings etc. >> >> Yes, I too think consistency is key here. As you said, we need to >> settle on the expected behaviour and enforce it uniformly across the >> fconf code. Let's revisit this code after the v2.3 release. >> >>> I would like to point out that using asserts here is different from >>> what is documented in the coding guidelines. The guidelines >>> explicitly spells out using asserts for "programming errors". >>> Now, is having a bad DTB considered a programming error? ;) The DTB >>> is platform data as opposed to code. The guidelines might need to be >>> updated based on the conclusion here. >> >> Now that you point it out, and after taking a closer look at [1], I >> think I was wrong. A bad DTB seems more like an integration error >> than a programming error to me, and thus should be handled with >> runtime checks according to the current guidelines. Incorrect values >> for mandatory properties should probably be treated as unrecoverable >> errors (causing a panic) and incorrect/missing optional properties as >> recoverable errors (issuing a warning message). >> >> [1] >> https://trustedfirmware-a.readthedocs.io/en/latest/process/coding-guideline… >> >> >>> Also note the couple of scenarios i mentioned in an earlier email. >>> Platforms like RPI4 don't generally enable TBBR and the DTB image >>> could get corrupt or be modified on purpose. On a release build, >>> this could cause silent corruption. Panic() would avoid this. >>> >>> In any case, it would be good to settle on the expected behavior for >>> each of these abnormal cases. I don't have a strong preference for >>> asserts or panics here, since each has its pros and cons as both of >>> you called out. >>> >>> Thanks >>> Raghu > -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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TF-A Tech Forum Agenda @ Thr 18th June 2020 16:00-1700 BST

by Joanna Farley

Hi All, The next TF-A Tech Forum is scheduled for Thu 18th June 2020 16:00 – 17:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know. Note the new time that is an hour earlier then previous sessions. Agenda: * TF-A Unit Level Testing - Presented by Lauren Wehrmeister * General explanation of the new approach for Unit Testing in TF-A. * Optional TF-A Mailing List Topic Discussions If TF-A contributors have anything they wish to present at any future TF-A tech forum please contact me to have that scheduled. Thanks Joanna

5 years, 4 months

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Re: [TF-A] Upgrading libfdt library

by Madhukar Pappireddy

Hi Alexei, To be clear, my current effort is to upgrade the libfdt source files in TF-A. I am not sure why the libfdt source was not integrated into TF-A as a preloaded source tree similar to MbedTLS. Perhaps, any TF-A veteran can help answer this question? Since there is an ongoing effort in the TF-A project to move to CMake build framework, I did not plan to integrate libfdt Makefile into TF-A. Hi Yann, Between commits aadd0b6 (the current version in TF-A for libfdt files) and 85e5d83, I have noticed bug fixes, code cleanups. I am not familiar with the dtc project. I can push a WIP patch with libfdt source files picked from commit 85e5d83. Please let me know if you see any issues with ST platforms. Thanks, Madhukar -----Original Message----- From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Yann GAUTIER via TF-A Sent: Monday, June 15, 2020 10:26 AM To: tf-a(a)lists.trustedfirmware.org Subject: Re: [TF-A] Upgrading libfdt library Hi Madhukar, We had seen some issue on STM32MP1 with the previous libfdt rebase, that led to the ticket [1]. And then a partial revert [2]. I'll then try this new version to check if boot time doesn't increase too much. Do you expect other changes than the one changing __ASSEMBLY__ to __ASSEMBLER__? And maybe some updates in libfdt.mk file? If you push this new version to gerrit, it will be easier to fetch and test, as a WIP if it is better for you? Regards, Yann [1] https://github.com/ARM-software/tf-issues/issues/643 [2] https://github.com/ARM-software/arm-trusted-firmware/commit/00f588bf2cc5298… On 6/15/20 2:18 PM, Alexei Fedorov via TF-A wrote: > Hi Madhukar, > > I'm wondering why we need to integrate libfdt sources in TF-A? Why > cannot we use the same option as for MbedTls when the build system > gets the path to the preloaded source tree? > > Regards. > > Alexei > > ---------------------------------------------------------------------- > -- > *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of > Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org> > *Sent:* 13 June 2020 01:04 > *To:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com> > *Cc:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org> > *Subject:* Re: [TF-A] Upgrading libfdt library > > Hi Madhukar, > > Before we merge this change, can you please explain how we arrived at > this specific version? Are we tracking the stable version of the library? > > What would be the testing criteria before merging the library? Does > tftf provide any tests that can act as a smoking gun? > > Does it make sense to ask platform owners to test the specific version > you plan to merge? This way we would have more confidence in the library. > > -Varun > > *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> *On Behalf Of > *Madhukar Pappireddy via TF-A > *Sent:* Friday, June 12, 2020 4:48 PM > *To:* tf-a(a)lists.trustedfirmware.org > *Subject:* [TF-A] Upgrading libfdt library > > *External email: Use caution opening links or attachments* > > Hello, > > I am planning to upgrade libfdt library source files in TF-A. They > haven’t been updated for a while. As the project moves towards > improving the fconf framework and adding more properties in device > tree source files, we rely more on libfdt APIs. I have done some > preliminary investigation to check if there is any performance penalty > in upgrading the libfdt source files integrated into TF-A from the > current version(which corresponds to commit aadd0b6 in the dtc repo > [1]) to master commit (85e5d83). I have run some basics tests on both > x86 and > aarch64 machines and I have not seen any performance degradation. I > plan to push a patch shortly to integrate the latest version of libfdt > files in TF-A. > > Please let me know if you are aware of any performance issues or have > other concerns. > > [1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git > > Thanks, > > Madhu > > -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] Upgrading libfdt library

by Yann GAUTIER

Hi Madhukar, We had seen some issue on STM32MP1 with the previous libfdt rebase, that led to the ticket [1]. And then a partial revert [2]. I'll then try this new version to check if boot time doesn't increase too much. Do you expect other changes than the one changing __ASSEMBLY__ to __ASSEMBLER__? And maybe some updates in libfdt.mk file? If you push this new version to gerrit, it will be easier to fetch and test, as a WIP if it is better for you? Regards, Yann [1] https://github.com/ARM-software/tf-issues/issues/643 [2] https://github.com/ARM-software/arm-trusted-firmware/commit/00f588bf2cc5298… On 6/15/20 2:18 PM, Alexei Fedorov via TF-A wrote: > Hi Madhukar, > > I'm wondering why we need to integrate libfdt sources in TF-A? Why > cannot we use the same option as for MbedTls when the build system gets > the path to the preloaded source tree? > > Regards. > > Alexei > > ------------------------------------------------------------------------ > *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Varun > Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org> > *Sent:* 13 June 2020 01:04 > *To:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com> > *Cc:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org> > *Subject:* Re: [TF-A] Upgrading libfdt library > > Hi Madhukar, > > Before we merge this change, can you please explain how we arrived at > this specific version? Are we tracking the stable version of the library? > > What would be the testing criteria before merging the library? Does tftf > provide any tests that can act as a smoking gun? > > Does it make sense to ask platform owners to test the specific version > you plan to merge? This way we would have more confidence in the library. > > -Varun > > *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> *On Behalf Of > *Madhukar Pappireddy via TF-A > *Sent:* Friday, June 12, 2020 4:48 PM > *To:* tf-a(a)lists.trustedfirmware.org > *Subject:* [TF-A] Upgrading libfdt library > > *External email: Use caution opening links or attachments* > > Hello, > > I am planning to upgrade libfdt library source files in TF-A. They > haven’t been updated for a while. As the project moves towards improving > the fconf framework and adding more properties in device tree source > files, we rely more on libfdt APIs. I have done some preliminary > investigation to check if there is any performance penalty in upgrading > the libfdt source files integrated into TF-A from the current > version(which corresponds to commit aadd0b6 in the dtc repo [1]) to > master commit (85e5d83). I have run some basics tests on both x86 and > aarch64 machines and I have not seen any performance degradation. I plan > to push a patch shortly to integrate the latest version of libfdt files > in TF-A. > > Please let me know if you are aware of any performance issues or have > other concerns. > > [1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git > > Thanks, > > Madhu > >

5 years, 4 months

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Re: [TF-A] Upgrading libfdt library

by Alexei Fedorov

Hi Madhukar, I'm wondering why we need to integrate libfdt sources in TF-A? Why cannot we use the same option as for MbedTls when the build system gets the path to the preloaded source tree? Regards. Alexei ________________________________ From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org> Sent: 13 June 2020 01:04 To: Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com> Cc: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org> Subject: Re: [TF-A] Upgrading libfdt library Hi Madhukar, Before we merge this change, can you please explain how we arrived at this specific version? Are we tracking the stable version of the library? What would be the testing criteria before merging the library? Does tftf provide any tests that can act as a smoking gun? Does it make sense to ask platform owners to test the specific version you plan to merge? This way we would have more confidence in the library. -Varun From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Madhukar Pappireddy via TF-A Sent: Friday, June 12, 2020 4:48 PM To: tf-a(a)lists.trustedfirmware.org Subject: [TF-A] Upgrading libfdt library External email: Use caution opening links or attachments Hello, I am planning to upgrade libfdt library source files in TF-A. They haven’t been updated for a while. As the project moves towards improving the fconf framework and adding more properties in device tree source files, we rely more on libfdt APIs. I have done some preliminary investigation to check if there is any performance penalty in upgrading the libfdt source files integrated into TF-A from the current version(which corresponds to commit aadd0b6 in the dtc repo [1]) to master commit (85e5d83). I have run some basics tests on both x86 and aarch64 machines and I have not seen any performance degradation. I plan to push a patch shortly to integrate the latest version of libfdt files in TF-A. Please let me know if you are aware of any performance issues or have other concerns. [1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git Thanks, Madhu

5 years, 4 months

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Re: [TF-A] Question on confine_index_array.h import in tf-a

by Sandrine Bailleux

Hello Etienne, On 6/10/20 1:19 PM, Etienne Carriere via TF-A wrote: > Dear all, > > As part of a patchset series review (topic scmi-msg), change [1] > imports confine_array_index.h header file from OP-TEE OS repository. > The file originates from the open source Fuschia project, see link in > commit message of [1]. > > As being imported for external packages, the header file inherits > Fushca and OP-TEE notices. > The helper function can protect some data structure from side channel > attacks leveraging index indirect access overflows during speculative > execution. > It is not Arm copyright. It is BSD-3-Clause license. > I'll add an entry in the docs/license.rst for the file. > > Where to locate the file? > It is ok to add such a file in include/common? > Does it deserve a specific lib path, like > include/lib/speculconfie_array_index.h? > Maybe add as include/lib/cpus/confine_array_index.h as it is CPU > speculative matters? Before we discuss the location of this header file, have we considered using the compiler support for speculative execution mitigations instead? I am referring to the __builtin_speculation_safe_value() macro, which I believe achieves the same goal as the code you propose to introduce here, i.e. protecting against Spectre v1 bounds-check bypass attacks. TF-A already uses this compiler builtin today and provides a wrapper macro around it, see SPECULATION_SAFE_VALUE() in include/lib/utils_def.f (although I would argue this is not the best location one could think of...). For reference, this was introduced by commit [1]. According to Arm's whitepaper [2], the support for this compiler builtin was added in GCC 9 and LLVM/Clang was to follow shortly. If these versions are too recent for you, then I believe the official location to get equivalent code is [3]. As stated there: The header file provided here allows a migration path to using the builtin function for users who are unable to immediately upgrade to a compiler which supports the builtin. So I would prefer we get the code from there rather than from the OP-TEE project, which got it from the Fuschia project ;) This is licensed under the Boost Software License 1.0, which we've never used in TF-A so I would need to check with our legal department whether this is OK, but I don't expect any issues there as this is described as a permissive license only requiring preservation of copyright and license notices. This is assuming that both header files (the one from OP-TEE and the one from the Arm software Github repo) are equivalent... Is this the case? Is the code provided in OP-TEE perhaps more optimized? Regards, Sandrine [1] https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=9edd… [2] https://developer.arm.com/support/arm-security-updates/speculative-processo… [3] https://github.com/ARM-software/speculation-barrier

5 years, 4 months

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Invitation: TF-A Tech Forum @ Every 2 weeks from 16:00 to 17:00 on Thursday (BST) (tf-a@lists.trustedfirmware.org)

by Bill Fletcher

You have been invited to the following event. Title: TF-A Tech Forum We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC. Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr… Firmware is inviting you to a scheduled Zoom meeting.Join Zoom Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US (San Jose)Dial by your location        +1 646 558 8656 US (New York)        +1 669 900 9128 US (San Jose)        877 853 5247 US Toll-free        888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your local number: https://zoom.us/u/ad27hc6t7h   When: Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time Calendar: tf-a(a)lists.trustedfirmware.org Who: * Bill Fletcher- creator * tf-a(a)lists.trustedfirmware.org Event details: https://www.google.com/calendar/event?action=VIEW&eid=NWlub3Ewdm1tMmk1cTJrM… Invitation from Google Calendar: https://www.google.com/calendar/ You are receiving this courtesy email at the account tf-a(a)lists.trustedfirmware.org because you are an attendee of this event. To stop receiving future updates for this event, decline this event. Alternatively, you can sign up for a Google Account at https://www.google.com/calendar/ and control your notification settings for your entire calendar. Forwarding this invitation could allow any recipient to send a response to the organiser and be added to the guest list, invite others regardless of their own invitation status or to modify your RSVP. Learn more at https://support.google.com/calendar/answer/37135#forwarding

5 years, 4 months

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Upgrading libfdt library

by Madhukar Pappireddy

Hello, I am planning to upgrade libfdt library source files in TF-A. They haven't been updated for a while. As the project moves towards improving the fconf framework and adding more properties in device tree source files, we rely more on libfdt APIs. I have done some preliminary investigation to check if there is any performance penalty in upgrading the libfdt source files integrated into TF-A from the current version(which corresponds to commit aadd0b6 in the dtc repo [1]) to master commit (85e5d83). I have run some basics tests on both x86 and aarch64 machines and I have not seen any performance degradation. I plan to push a patch shortly to integrate the latest version of libfdt files in TF-A. Please let me know if you are aware of any performance issues or have other concerns. [1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git Thanks, Madhu

5 years, 4 months

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Re: [TF-A] ATF LTS version

by Varun Wadekar

Hello Matteo, Apologies for still using an outdated term. I have trained myself to get used to "TF-A" - looks like I am still not there. >> The idea has also been just raised to the Trusted Firmware project Board for initial consideration and we will be all very keen to understand how much interest there is from the wider TF-A community of adopters and external (non-Arm) maintainers That is good to hear. For the exact scope, I think we can assume the usual expectations from any LTS software stack - stability, performance, security, bug fixes along with maintenance support. We are open to discussing the cadence and any other operational commitments. @Francois, from the description of Trusted Substrate looks like you also expect the sub-projects to provide LTS versions for the project as a whole to succeed (?) -Varun -----Original Message----- From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Matteo Carlini via TF-A Sent: Thursday, June 11, 2020 4:25 AM To: tf-a(a)lists.trustedfirmware.org Subject: Re: [TF-A] ATF LTS version External email: Use caution opening links or attachments Hi Francois, > I'd be happy to know more about what you see as TFA LTS: exact scope, number of versions, duration, operational commitments (zero-day...). > Do you have other firmware LTS needs? Agree. That’s precisely what I was hinting to Varun, when mentioning concrete requirements for the LTS scheme. > Trusted Substrate is the aggregation of { TFA, OP-TEE, some TEE apps such as firmwareTPM, U-Boot }. > Trusted Substrate effort is led by Linaro members and is going to be set up as a more open project. First time I heard about it. Good to know, but I guess we'll need to discuss the intersection and collaboration with the Trusted Firmware project at some point. Having a LTS versioning scheme for the Trusted Firmware hosted projects should be theoretically either in the scope of the Project itself or, if the Board agrees, appointed to some other project/entity. > Our end goal is to enable unified, transactional, robust (anti-bricking, anti rollback) UEFI OTA on both U-Boot and EDK2. Fair, but IMHO this has little to do with Arm Secure world software LTS releases (TF-A/Hafnium/OP-TEE/TAs, TF-M)...probably best to discuss aside, this is not in scope of what Varun is raising. Thanks Matteo -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] ATF LTS version

by Joanna Farley

I should also mention the Release processes we follow and the attempt to indicated the deprecation of interfaces in advance in the effort to maintain compatibility https://trustedfirmware-a.readthedocs.io/en/latest/about/release-informatio… On 11/06/2020, 14:47, "TF-A on behalf of Joanna Farley via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Hi Varun, I guess this suggestion came in response to last weeks Tech Forum discussion from a question about experiences people had from migrating to different TF-A tagged releases. In general we try and keep the tip of Master at tagged release quality through an extensive CI system ran on each patch. I appreciate this CI is currently a little opaque to many contributors as this is still in the process of being transitioned to the OpenCI hosted by Trustedfirmware.org servers which will be visible to all. As mentioned in the recent "Overview of the TF-A v2.3 Release" presentation on https://www.trustedfirmware.org/meetings/tf-a-technical-forum/ the additional testing done for a 6 monthly tagged release is quite minimal and the larger work is ensuring all documentation is up to date. Additionally all new features are generally behind their own build flags but I appreciate it is some work for a tagged release to be absorbed into product offerings. I asked at the tech forum last week what more we could do to allow releases to be integrated more easily. On the call it was requested if we could disable weak bindings to symbols so it could be more easily seen where platform decisions may need to be made and we will look into this. If there are any more adjustments to the way tagged releases are produced please let us know. One thing that had been considered briefly was the production of a security bug only branch that was maintained only between 6 month tagged releases before being replaced by the next security bug only branch based on the next 6 month release but that has not progressed very far as a proposal as until your email here it was perceived to not be in demand. A LTS branch is a larger endeavour as it sounds like something that includes more than security fixes and I look forward to you elaborating more as Matteo requests. Thanks Joanna On 11/06/2020, 12:19, "Matteo Carlini via TF-A" <tf-a(a)lists.trustedfirmware.org> wrote: Hi Varun, Thanks for raising this topic (but please do embrace the official terminology “TF-A”…we never really promoted ATF and it's also absolutely outdated now 😉 ). Arm has received different queries over time on supporting Trusted Firmware LTS releases, but the effort to sustain them is something that the Arm engineering team alone cannot really afford and commit to (either in the TF-A or TF-M space). The idea has also been just raised to the Trusted Firmware project Board for initial consideration and we will be all very keen to understand how much interest there is from the wider TF-A community of adopters and external (non-Arm) maintainers, so to evaluate the possibility of a more concrete proposal to be carried on within the community Project. I guess it will also be good to start by elaborating more concretely on the requirements that you would like to see in an hypothetical LTS versioning scheme. Thanks Matteo > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A > Sent: 10 June 2020 22:47 > To: tf-a(a)lists.trustedfirmware.org > Subject: [TF-A] ATF LTS version > > Hello team, > > To extend the discussion around version upgrades from our last call, I would like to understand if there is enough interest around generating a LTS version of the TF-A to alleviate the pain. > > For NVIDIA, this would be helpful as it streamlines the upgrade path for our devices in the field. The LTS version will guarantee security fixes, bug fixes, stability fixes for the longer term and we won’t have to upgrade the entire firmware to get these goodies. > > It would be interesting to see what OEMs and maintainers think about this? Has this been discussed at tf.org or Arm internally? > > -Varun -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] ATF LTS version

by Joanna Farley

Hi Varun, I guess this suggestion came in response to last weeks Tech Forum discussion from a question about experiences people had from migrating to different TF-A tagged releases. In general we try and keep the tip of Master at tagged release quality through an extensive CI system ran on each patch. I appreciate this CI is currently a little opaque to many contributors as this is still in the process of being transitioned to the OpenCI hosted by Trustedfirmware.org servers which will be visible to all. As mentioned in the recent "Overview of the TF-A v2.3 Release" presentation on https://www.trustedfirmware.org/meetings/tf-a-technical-forum/ the additional testing done for a 6 monthly tagged release is quite minimal and the larger work is ensuring all documentation is up to date. Additionally all new features are generally behind their own build flags but I appreciate it is some work for a tagged release to be absorbed into product offerings. I asked at the tech forum last week what more we could do to allow releases to be integrated more easily. On the call it was requested if we could disable weak bindings to symbols so it could be more easily seen where platform decisions may need to be made and we will look into this. If there are any more adjustments to the way tagged releases are produced please let us know. One thing that had been considered briefly was the production of a security bug only branch that was maintained only between 6 month tagged releases before being replaced by the next security bug only branch based on the next 6 month release but that has not progressed very far as a proposal as until your email here it was perceived to not be in demand. A LTS branch is a larger endeavour as it sounds like something that includes more than security fixes and I look forward to you elaborating more as Matteo requests. Thanks Joanna On 11/06/2020, 12:19, "Matteo Carlini via TF-A" <tf-a(a)lists.trustedfirmware.org> wrote: Hi Varun, Thanks for raising this topic (but please do embrace the official terminology “TF-A”…we never really promoted ATF and it's also absolutely outdated now 😉 ). Arm has received different queries over time on supporting Trusted Firmware LTS releases, but the effort to sustain them is something that the Arm engineering team alone cannot really afford and commit to (either in the TF-A or TF-M space). The idea has also been just raised to the Trusted Firmware project Board for initial consideration and we will be all very keen to understand how much interest there is from the wider TF-A community of adopters and external (non-Arm) maintainers, so to evaluate the possibility of a more concrete proposal to be carried on within the community Project. I guess it will also be good to start by elaborating more concretely on the requirements that you would like to see in an hypothetical LTS versioning scheme. Thanks Matteo > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A > Sent: 10 June 2020 22:47 > To: tf-a(a)lists.trustedfirmware.org > Subject: [TF-A] ATF LTS version > > Hello team, > > To extend the discussion around version upgrades from our last call, I would like to understand if there is enough interest around generating a LTS version of the TF-A to alleviate the pain. > > For NVIDIA, this would be helpful as it streamlines the upgrade path for our devices in the field. The LTS version will guarantee security fixes, bug fixes, stability fixes for the longer term and we won’t have to upgrade the entire firmware to get these goodies. > > It would be interesting to see what OEMs and maintainers think about this? Has this been discussed at tf.org or Arm internally? > > -Varun -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] ATF LTS version

by Matteo Carlini

Hi Francois, > I'd be happy to know more about what you see as TFA LTS: exact scope, number of versions, duration, operational commitments (zero-day...). > Do you have other firmware LTS needs? Agree. That’s precisely what I was hinting to Varun, when mentioning concrete requirements for the LTS scheme. > Trusted Substrate is the aggregation of { TFA, OP-TEE, some TEE apps such as firmwareTPM, U-Boot }. > Trusted Substrate effort is led by Linaro members and is going to be set up as a more open project. First time I heard about it. Good to know, but I guess we'll need to discuss the intersection and collaboration with the Trusted Firmware project at some point. Having a LTS versioning scheme for the Trusted Firmware hosted projects should be theoretically either in the scope of the Project itself or, if the Board agrees, appointed to some other project/entity. > Our end goal is to enable unified, transactional, robust (anti-bricking, anti rollback) UEFI OTA on both U-Boot and EDK2. Fair, but IMHO this has little to do with Arm Secure world software LTS releases (TF-A/Hafnium/OP-TEE/TAs, TF-M)...probably best to discuss aside, this is not in scope of what Varun is raising. Thanks Matteo

5 years, 4 months

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Re: [TF-A] ATF LTS version

by Matteo Carlini

Hi Varun, Thanks for raising this topic (but please do embrace the official terminology “TF-A”…we never really promoted ATF and it's also absolutely outdated now 😉 ). Arm has received different queries over time on supporting Trusted Firmware LTS releases, but the effort to sustain them is something that the Arm engineering team alone cannot really afford and commit to (either in the TF-A or TF-M space). The idea has also been just raised to the Trusted Firmware project Board for initial consideration and we will be all very keen to understand how much interest there is from the wider TF-A community of adopters and external (non-Arm) maintainers, so to evaluate the possibility of a more concrete proposal to be carried on within the community Project. I guess it will also be good to start by elaborating more concretely on the requirements that you would like to see in an hypothetical LTS versioning scheme. Thanks Matteo > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A > Sent: 10 June 2020 22:47 > To: tf-a(a)lists.trustedfirmware.org > Subject: [TF-A] ATF LTS version > > Hello team, > > To extend the discussion around version upgrades from our last call, I would like to understand if there is enough interest around generating a LTS version of the TF-A to alleviate the pain. > > For NVIDIA, this would be helpful as it streamlines the upgrade path for our devices in the field. The LTS version will guarantee security fixes, bug fixes, stability fixes for the longer term and we won’t have to upgrade the entire firmware to get these goodies. > > It would be interesting to see what OEMs and maintainers think about this? Has this been discussed at tf.org or Arm internally? > > -Varun

5 years, 4 months

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Re: [TF-A] ATF LTS version

by François Ozog

Hi Varun, There are early discussions in Linaro on what would mean setting up "Collaborative LTS" for what we call Trusted Substrate (see below signature). I'd be happy to know more about what you see as TFA LTS: exact scope, number of versions, duration, operational commitments (zero-day...). Do you have other firmware LTS needs? Cheers François-Frédéric Ozog Linaro Trusted Substrate is the aggregation of { TFA, OP-TEE, some TEE apps such as firmwareTPM, U-Boot }. Trusted Substrate effort is led by Linaro members and is going to be set up as a more open project. Our end goal is to enable unified, transactional, robust (anti-bricking, anti rollback) UEFI OTA on both U-Boot and EDK2. On Wed, 10 Jun 2020 at 23:47, Varun Wadekar via TF-A < tf-a(a)lists.trustedfirmware.org> wrote: > Hello team, > > > > To extend the discussion around version upgrades from our last call, I > would like to understand if there is enough interest around generating a > LTS version of the TF-A to alleviate the pain. > > > > For NVIDIA, this would be helpful as it streamlines the upgrade path for > our devices in the field. The LTS version will guarantee security fixes, > bug fixes, stability fixes for the longer term and we won’t have to upgrade > the entire firmware to get these goodies. > > > > It would be interesting to see what OEMs and maintainers think about this? > Has this been discussed at tf.org or Arm internally? > > > > -Varun > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a > -- François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group* T: +33.67221.6485 francois.ozog(a)linaro.org | Skype: ffozog

5 years, 4 months

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Updated invitation with note: TF-A Tech Forum @ Every 2 weeks from 17:00 to 18:00 on Thursday from Thu 26 Mar to Wed 17 Jun (GMT) (tf-a@lists.trustedfirmware.org)

by Bill Fletcher

This event has been changed with this note: "Starting 18th June, the TF-A Tech Forum will be moved earlier by 1 hour to 1600 UK time (1500 UTC). This change is to avoid overlapping the TF Technical Steering Committee call. A new invite will be posted to the TF-A mailing list and on the trustedfirmware.org website." Title: TF-A Tech Forum We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC. Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr… Firmware is inviting you to a scheduled Zoom meeting.Join Zoom Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US (San Jose)Dial by your location        +1 646 558 8656 US (New York)        +1 669 900 9128 US (San Jose)        877 853 5247 US Toll-free        888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your local number: https://zoom.us/u/ad27hc6t7h   When: Every 2 weeks from 17:00 to 18:00 on Thursday from Thu 26 Mar to Wed 17 Jun United Kingdom Time (changed) Where: Zoom Calendar: tf-a(a)lists.trustedfirmware.org Who: (Guest list has been hidden at organiser's request) Event details: https://www.google.com/calendar/event?action=VIEW&eid=N3ZoNDBuZzZnM2k4cGszY… Invitation from Google Calendar: https://www.google.com/calendar/ You are receiving this courtesy email at the account tf-a(a)lists.trustedfirmware.org because you are an attendee of this event. To stop receiving future updates for this event, decline this event. Alternatively, you can sign up for a Google Account at https://www.google.com/calendar/ and control your notification settings for your entire calendar. Forwarding this invitation could allow any recipient to send a response to the organiser and be added to the guest list, invite others regardless of their own invitation status or to modify your RSVP. Learn more at https://support.google.com/calendar/answer/37135#forwarding

5 years, 4 months

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Updated invitation with note: TF-A Tech Forum @ Every 2 weeks from 17:00 to 18:00 on Thursday from Thu 7 May to Wed 17 Jun (BST) (tf-a@lists.trustedfirmware.org)

by Bill Fletcher

This event has been changed with this note: "Starting 18th June, the TF-A Tech Forum will be moved earlier by 1 hour to 1600 UK time (1500 UTC). This change is to avoid overlapping the TF Technical Steering Committee call. A new invite will be posted to the TF-A mailing list and on the trustedfirmware.org website." Title: TF-A Tech Forum We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC. Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr… Firmware is inviting you to a scheduled Zoom meeting.Join Zoom Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US (San Jose)Dial by your location        +1 646 558 8656 US (New York)        +1 669 900 9128 US (San Jose)        877 853 5247 US Toll-free        888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your local number: https://zoom.us/u/ad27hc6t7h   When: Every 2 weeks from 17:00 to 18:00 on Thursday from Thu 7 May to Wed 17 Jun United Kingdom Time (changed) Where: Zoom Calendar: tf-a(a)lists.trustedfirmware.org Who: (Guest list has been hidden at organiser's request) Event details: https://www.google.com/calendar/event?action=VIEW&eid=N3ZoNDBuZzZnM2k4cGszY… Invitation from Google Calendar: https://www.google.com/calendar/ You are receiving this courtesy email at the account tf-a(a)lists.trustedfirmware.org because you are an attendee of this event. To stop receiving future updates for this event, decline this event. Alternatively, you can sign up for a Google Account at https://www.google.com/calendar/ and control your notification settings for your entire calendar. Forwarding this invitation could allow any recipient to send a response to the organiser and be added to the guest list, invite others regardless of their own invitation status or to modify your RSVP. Learn more at https://support.google.com/calendar/answer/37135#forwarding

5 years, 4 months

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Cancelled event: TF-A Tech Forum @ (BST) (tf-a@lists.trustedfirmware.org)

by Bill Fletcher

This event has been cancelled. Title: TF-A Tech Forum We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC. Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr… Firmware is inviting you to a scheduled Zoom meeting.Join Zoom Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US (San Jose)Dial by your location        +1 646 558 8656 US (New York)        +1 669 900 9128 US (San Jose)        877 853 5247 US Toll-free        888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your local number: https://zoom.us/u/ad27hc6t7h   When: United Kingdom Time Where: Zoom Calendar: tf-a(a)lists.trustedfirmware.org Who: (Guest list has been hidden at organiser's request) Invitation from Google Calendar: https://www.google.com/calendar/ You are receiving this courtesy email at the account tf-a(a)lists.trustedfirmware.org because you are an attendee of this event. To stop receiving future updates for this event, decline this event. Alternatively, you can sign up for a Google Account at https://www.google.com/calendar/ and control your notification settings for your entire calendar. Forwarding this invitation could allow any recipient to send a response to the organiser and be added to the guest list, invite others regardless of their own invitation status or to modify your RSVP. Learn more at https://support.google.com/calendar/answer/37135#forwarding

5 years, 4 months

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Re-scheduling TF-A Tech Forum earlier by 1 hour

by Bill Fletcher

Hi all, Starting 18th June, the TF-A Tech Forum will be moved earlier by 1 hour to 1600 UK time (1500 UTC). This change is to avoid overlapping with the TF Technical Steering Committee call. We'll delete the existing invite and send a new one to this list. Regards Bill -- [image: Linaro] <http://www.linaro.org/> *Bill Fletcher* | *Field Engineering* T: +44 7833 498336 <+44+7833+498336> bill.fletcher(a)linaro.org | Skype: billfletcher2020

5 years, 4 months

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ATF LTS version

by Varun Wadekar

Hello team, To extend the discussion around version upgrades from our last call, I would like to understand if there is enough interest around generating a LTS version of the TF-A to alleviate the pain. For NVIDIA, this would be helpful as it streamlines the upgrade path for our devices in the field. The LTS version will guarantee security fixes, bug fixes, stability fixes for the longer term and we won't have to upgrade the entire firmware to get these goodies. It would be interesting to see what OEMs and maintainers think about this? Has this been discussed at tf.org or Arm internally? -Varun

5 years, 4 months

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Measured Boot in TF-A

by Alexei Fedorov

Hello all, The initial patch for Measured Boot has been split into 5 separates buildable ones: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3806 https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4473 https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4508 https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4509 https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4510 and are ready for review/merge. The design follows "TF-A Design Notes for Measured Boot" document . The number of API changes and code modifications based on the received feedback were made, and the most important are: 1. TPM hash algorithm is now independent from the one used by Trusted Boot and can be set separately to a different value. 2. Size of Event Log is passed as a driver build option and can be tuned to meet platform specific requirements (debug/release, number of images loaded, etc.). 3. Driver accepts platform specific table of images to be loaded/measured. 4. PCR index to use for TMP records is passed in platform specific table (see above) and can be set individually for each image. Regards. Alexei

5 years, 4 months

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Question on confine_index_array.h import in tf-a

by Etienne Carriere

Dear all, As part of a patchset series review (topic scmi-msg), change [1] imports confine_array_index.h header file from OP-TEE OS repository. The file originates from the open source Fuschia project, see link in commit message of [1]. As being imported for external packages, the header file inherits Fushca and OP-TEE notices. The helper function can protect some data structure from side channel attacks leveraging index indirect access overflows during speculative execution. It is not Arm copyright. It is BSD-3-Clause license. I'll add an entry in the docs/license.rst for the file. Where to locate the file? It is ok to add such a file in include/common? Does it deserve a specific lib path, like include/lib/speculconfie_array_index.h? Maybe add as include/lib/cpus/confine_array_index.h as it is CPU speculative matters? Could you help [1] review to progress? [1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4055 Regards, Etienne

5 years, 4 months

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Re: [TF-A] RK3399_BAUDRATE default value

by Hugh Cole-Baker

> On 6 Jun 2020, at 17:52, Heiko Stübner via TF-A <tf-a(a)lists.trustedfirmware.org> wrote: > > Hi Walter, > > Am Freitag, 5. Juni 2020, 22:45:25 CEST schrieb Walter Lozano via TF-A: >> I have noticed that default baudrate for rk3399 board RK3399_BAUDRATE >> defined in plat/rockchip/rk3399/rk3399_def.h is 115200 while U-boot >> default value and most documentation points to a value of 1500000 for >> console. > > console baudrate on rk3399 differ a lot between boards. There are a > number using the 1.5MHz and another big number using 115200 > (including but not limited to the ChromeOS devices from the Gru line). > > Hence we have the code that selects the actual baudrate from the > devicetree attached by u-boot when calling TF-A. > > So I guess it should stay as it is right now. On the RK3399 there are currently a couple of roadblocks preventing this selection of the baudrate from the devicetree from working. Firstly in U-Boot, SPL_ATF_NO_PLATFORM_PARAM is forced on when selecting ROCKCHIP_RK3399 in Kconfig [1]. Secondly in TF-A the 64K buffer used to store the passed devicetree isn't large enough to fit some of the RK3399 device tree blobs, as I found when removing SPL_ATF_NO_PLATFORM_PARAM from U-Boot. I guess the issue in TF-A needs to be fixed first before passing the platform parameter can be enabled in U-Boot, I've submitted a TF-A patch to increase the buffer size [2]. [1]: https://gitlab.denx.de/u-boot/u-boot/-/blob/61853a7ac7e167d90899ec4e99d2e07… [2]: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4512 > Heiko > > >> This of course means that messages printed by ATF are not visible by >> default in this context. >> >> The change from 1500000 to 115200 was introduced in >> 0c05748bdebfad9fa43a80962186438bb8fbce62, >> >> https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=0c05… >> >> with the following message >> >> commit 0c05748bdebfad9fa43a80962186438bb8fbce62 >> Author: Caesar Wang <wxt(a)rock-chips.com> >> Date: Tue Apr 19 20:42:17 2016 +0800 >> >> rockchip: fixes for the required >> >> This patch has the following change for rk3399. >> >> * Set the uart to 115200 since the loader decide to set >> uart baud to 115200Hz. So the ATF also should set uart baud to 115200. >> [..] >> >> However, I'm not sure it this still applies. >> >> I'll be happy to submit a patch to update the value if it is OK. >> >> Regards, >> >> Walter >> >> > > > > > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] GICV3: system interface EOI ordering RFC

by Raghu Krishnamurthy

Hello, Sorry for chiming in late. Are we sure that the msr/mrs to the GICv3 EOI register is not a context synchronizing event or ensures ordering itself ? Also did the addition of DSB() fix the issue ? If yes, can you try adding a delay or a few NOP's/dummy instructions or an ISB to see if the issue goes away? We need to know the right thing to do architecturally and confirm that the issue is really due to reordering at the core before adding the DSB. Adding a DSB might be masking a timing issue. -Raghu On 6/8/20 4:47 AM, Sandeep Tripathy via TF-A wrote: >> -----Original Message----- >> From: Soby Mathew [mailto:Soby.Mathew@arm.com] >> Sent: Monday, June 08, 2020 3:36 PM >> To: Sandeep Tripathy; Olivier Deprez; tf-a(a)lists.trustedfirmware.org >> Cc: nd >> Subject: RE: [TF-A] GICV3: system interface EOI ordering RFC >> >> Just some inputs from my side: >> I agree we need at least a dsb() after the write to MMIO region to silence >> the >> peripheral and before the EOI at GIC sysreg interface. Adding it to the >> GIC EOI > > Thanks for the confirmation. Now it’s about choosing the right place. > >> API seems the logical thing to do but as Olivier mentions, there are >> interrupt >> handler which do not deal with MMIO (eg: the Systimer interrupt) so adding >> it >> to GICv3 API might be arduous for such handlers. >> >> So there is a choice here to let the interrupt handlers to deal with >> ensuring >> completeness before EOI at sysreg interface or adding it to GICv3 EOI API >> and >> take the overhead for interrupt handlers which do not have to deal with >> MMIO. >> > > Yes I feel either of these is a must to guarantee functionality > architecturally though > both approach end up with some unnecessary overhead. > > If GICv3 api takes care then it is an overhead for some ISRs dealing with > non-MMIO. > At present I do not see an active use case in reference implementation where > sys timer > ISR is in a performance intensive path where one additional DSB will be > perceivable. > But there may be some I could be totally wrong in this assumption (pmu/debug > or.. not sure). > Whereas I can certainly imagine some MMIO ISRs in performance critical path > where unnecessary > DSB is not acceptable at all. > > If the interrupt handler needs to ensure then it will generically add 'DSB' > as I think > the driver cannot and should not make assumptions about how EOI is done > afterwards. > That will be overhead for the ISRs dealing with MMIO peripherals and non > GIC-v3. > If we consider only GICv3+ then good. Otherwise I would prefer the > 'plat_ic_end_of_interrupt' > like Olivier mentioned with a #if GICv3 instead of each ISRs dealing with > it. > >> The GICv3 legacy MMIO CPU interface is deprecated for TF-A and the sys >> interface is the only one GICv3 driver in TF-A supports. > > Right we can ignore the GICv3 legacy mode but GICv2 will still remain ? > >> >> Best Regards >> Soby Mathew >> > > Thanks > Sandeep > >>> -----Original Message----- >>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandeep >>> Tripathy via TF-A >>> Sent: 08 June 2020 10:34 >>> To: Olivier Deprez <Olivier.Deprez(a)arm.com>; tf- >> a(a)lists.trustedfirmware.org >>> Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC >>> >>> Hi Olivier, >>>> -----Original Message----- >>>> From: Olivier Deprez [mailto:Olivier.Deprez@arm.com] >>>> Sent: Monday, June 08, 2020 1:14 PM >>>> To: tf-a(a)lists.trustedfirmware.org; Sandeep Tripathy >>>> Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC >>>> >>>> Hi Sandeep, >>>> >>>> gicv3_end_of_interrupt_sel1 is a static access helper macro. Its >>>> naming precisely tells what it does at gicv3 module level. It is >>>> called from >>> the weak >>>> plat_ic_end_of_interrupt function for BL32 image. >>>> >>>> I tend to think it is the driver responsibility to ensure the module >>> interrupt >>>> acknowledge register write is reaching HW in order (or "be visible to >>> all >>>> observers"). >>> >>> The driver should be agnostic of what interrupt controller is used and >>> its >>> behavior. >>> And since 'all' writes were to mmio ranges mapped Device(nGnRE) >>> /strongly-ordered(nGnRnE) >>> there was no such need. This is a special case for GICv3 system >>> interface only. >>> Adding at driver level a DSB is unnecessary for other interrupt >>> controllers. >>> >>>> Also I suspect adding a dsb might not be required generically for all >>> kind of IP. >>> >>> Here are you referring to the peripheral IP or interrupt controller IP ? >>> The issue is reordering at arm core itself (STR to device address Vs >>> msr(sysreg >>> write)). >>> So I think Its applicable for all IP. >>> >>>> Adding a barrier in generic code might incur an unnecessary >>>> bottleneck. >>> >>> But if there is a need to *ensure* presence of at least one DSB between >>> the >>> write transfer from core to device clear and gicv3 eoi icc register >>> write in a >>> generic way then what other option we have. >>>> >>>> Thus wouldn't it be better to add the barrier to the overridden >>>> platform function rather than in generic gicv3 code? >>> >>> That can be done but I feel this is more to do with gicv3 system >>> interface only. >>> Inside plat_xxx one has to check #if GICV3 ...and system interface. >>>> >>>> I have a put a comment in the review, we can continue the discussion >>> there. >>>> >>>> Regards, >>>> Olivier. >>>> >>> Thanks >>> Sandeep >>>> ________________________________________ >>>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of >>>> Sandeep Tripathy via TF-A <tf-a(a)lists.trustedfirmware.org> >>>> Sent: 05 June 2020 19:43 >>>> To: tf-a(a)lists.trustedfirmware.org >>>> Subject: [TF-A] GICV3: system interface EOI ordering RFC >>>> >>>> Hi, >>>> In a typical interrupt handling sequence we do 1-Read IAR >>>> 2-Do interrupt handling >>>> 3-Clear the interrupt at source , so that the device de-asserts IRQ >>> request to >>>> GIC >>>> >> I am suggesting a need of DSB here in case of GICv3 +. >>>> 4-Write to GIC cpu interface to do EOI. >>>> >>>> Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write >>>> over >>> AMBA >>>> interface. The >>>> Addresses are mapped with (nR) attribute. Hence the write transfers >>> from the >>>> core will be >>>> generated at step 3 and 4 in order. Please ignore the additional >>> buffers/bridges >>>> in path from >>>> core till peripheral which has to be dealt separately as per SOC. >>>> >>>> Query: I understand GICv3 system interface accesses are not over this >>> protocol >>>> and core will not >>>> follow the ordering rule ? >>>> >>>> I have observed spurious interrupt issue/manifestation ( I don't have >>> the >>>> transfers probed) in >>>> RTOS environment where I have a primitive GICv3 driver but I wonder >>>> why things does not fail in Linux or tf-a. If it is working because >>>> from step(3) to >>> step(4) we have >>>> barriers by chace >>>> due to other device register writes then I would suggest to have one >>>> in >>> the EOI >>>> clearing API itself. >>>> >>>> RFC: >>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454 >>>> >>>> Thanks >>>> Sandeep >>> -- >>> TF-A mailing list >>> TF-A(a)lists.trustedfirmware.org >>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] GICV3: system interface EOI ordering RFC

by Sandeep Tripathy

> -----Original Message----- > From: Soby Mathew [mailto:Soby.Mathew@arm.com] > Sent: Monday, June 08, 2020 3:36 PM > To: Sandeep Tripathy; Olivier Deprez; tf-a(a)lists.trustedfirmware.org > Cc: nd > Subject: RE: [TF-A] GICV3: system interface EOI ordering RFC > > Just some inputs from my side: > I agree we need at least a dsb() after the write to MMIO region to silence > the > peripheral and before the EOI at GIC sysreg interface. Adding it to the > GIC EOI Thanks for the confirmation. Now it’s about choosing the right place. > API seems the logical thing to do but as Olivier mentions, there are > interrupt > handler which do not deal with MMIO (eg: the Systimer interrupt) so adding > it > to GICv3 API might be arduous for such handlers. > > So there is a choice here to let the interrupt handlers to deal with > ensuring > completeness before EOI at sysreg interface or adding it to GICv3 EOI API > and > take the overhead for interrupt handlers which do not have to deal with > MMIO. > Yes I feel either of these is a must to guarantee functionality architecturally though both approach end up with some unnecessary overhead. If GICv3 api takes care then it is an overhead for some ISRs dealing with non-MMIO. At present I do not see an active use case in reference implementation where sys timer ISR is in a performance intensive path where one additional DSB will be perceivable. But there may be some I could be totally wrong in this assumption (pmu/debug or.. not sure). Whereas I can certainly imagine some MMIO ISRs in performance critical path where unnecessary DSB is not acceptable at all. If the interrupt handler needs to ensure then it will generically add 'DSB' as I think the driver cannot and should not make assumptions about how EOI is done afterwards. That will be overhead for the ISRs dealing with MMIO peripherals and non GIC-v3. If we consider only GICv3+ then good. Otherwise I would prefer the 'plat_ic_end_of_interrupt' like Olivier mentioned with a #if GICv3 instead of each ISRs dealing with it. > The GICv3 legacy MMIO CPU interface is deprecated for TF-A and the sys > interface is the only one GICv3 driver in TF-A supports. Right we can ignore the GICv3 legacy mode but GICv2 will still remain ? > > Best Regards > Soby Mathew > Thanks Sandeep > > -----Original Message----- > > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandeep > > Tripathy via TF-A > > Sent: 08 June 2020 10:34 > > To: Olivier Deprez <Olivier.Deprez(a)arm.com>; tf- > a(a)lists.trustedfirmware.org > > Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC > > > > Hi Olivier, > > > -----Original Message----- > > > From: Olivier Deprez [mailto:Olivier.Deprez@arm.com] > > > Sent: Monday, June 08, 2020 1:14 PM > > > To: tf-a(a)lists.trustedfirmware.org; Sandeep Tripathy > > > Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC > > > > > > Hi Sandeep, > > > > > > gicv3_end_of_interrupt_sel1 is a static access helper macro. Its > > > naming precisely tells what it does at gicv3 module level. It is > > > called from > > the weak > > > plat_ic_end_of_interrupt function for BL32 image. > > > > > > I tend to think it is the driver responsibility to ensure the module > > interrupt > > > acknowledge register write is reaching HW in order (or "be visible to > > all > > > observers"). > > > > The driver should be agnostic of what interrupt controller is used and > > its > > behavior. > > And since 'all' writes were to mmio ranges mapped Device(nGnRE) > > /strongly-ordered(nGnRnE) > > there was no such need. This is a special case for GICv3 system > > interface only. > > Adding at driver level a DSB is unnecessary for other interrupt > > controllers. > > > > > Also I suspect adding a dsb might not be required generically for all > > kind of IP. > > > > Here are you referring to the peripheral IP or interrupt controller IP ? > > The issue is reordering at arm core itself (STR to device address Vs > > msr(sysreg > > write)). > > So I think Its applicable for all IP. > > > > > Adding a barrier in generic code might incur an unnecessary > > > bottleneck. > > > > But if there is a need to *ensure* presence of at least one DSB between > > the > > write transfer from core to device clear and gicv3 eoi icc register > > write in a > > generic way then what other option we have. > > > > > > Thus wouldn't it be better to add the barrier to the overridden > > > platform function rather than in generic gicv3 code? > > > > That can be done but I feel this is more to do with gicv3 system > > interface only. > > Inside plat_xxx one has to check #if GICV3 ...and system interface. > > > > > > I have a put a comment in the review, we can continue the discussion > > there. > > > > > > Regards, > > > Olivier. > > > > > Thanks > > Sandeep > > > ________________________________________ > > > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of > > > Sandeep Tripathy via TF-A <tf-a(a)lists.trustedfirmware.org> > > > Sent: 05 June 2020 19:43 > > > To: tf-a(a)lists.trustedfirmware.org > > > Subject: [TF-A] GICV3: system interface EOI ordering RFC > > > > > > Hi, > > > In a typical interrupt handling sequence we do 1-Read IAR > > > 2-Do interrupt handling > > > 3-Clear the interrupt at source , so that the device de-asserts IRQ > > request to > > > GIC > > > >> I am suggesting a need of DSB here in case of GICv3 +. > > > 4-Write to GIC cpu interface to do EOI. > > > > > > Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write > > > over > > AMBA > > > interface. The > > > Addresses are mapped with (nR) attribute. Hence the write transfers > > from the > > > core will be > > > generated at step 3 and 4 in order. Please ignore the additional > > buffers/bridges > > > in path from > > > core till peripheral which has to be dealt separately as per SOC. > > > > > > Query: I understand GICv3 system interface accesses are not over this > > protocol > > > and core will not > > > follow the ordering rule ? > > > > > > I have observed spurious interrupt issue/manifestation ( I don't have > > the > > > transfers probed) in > > > RTOS environment where I have a primitive GICv3 driver but I wonder > > > why things does not fail in Linux or tf-a. If it is working because > > > from step(3) to > > step(4) we have > > > barriers by chace > > > due to other device register writes then I would suggest to have one > > > in > > the EOI > > > clearing API itself. > > > > > > RFC: > > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454 > > > > > > Thanks > > > Sandeep > > -- > > TF-A mailing list > > TF-A(a)lists.trustedfirmware.org > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] GICV3: system interface EOI ordering RFC

by Soby Mathew

Just some inputs from my side: I agree we need atleast a dsb() after the write to MMIO region to silence the peripheral and before the EOI at GIC sysreg interface. Adding it to the GIC EOI API seems the logical thing to do but as Olivier mentions, there are interrupt handler which do not deal with MMIO (eg: the Systimer interrupt) so adding it to GICv3 API might be arduous for such handlers. So there is a choice here to let the interrupt handlers to deal with ensuring completeness before EOI at sysreg interface or adding it to GICv3 EOI API and take the overhead for interrupt handlers which do not have to deal with MMIO. The GICv3 legacy MMIO CPU interface is deprecated for TF-A and the sys interface is the only one GICv3 driver in TF-A supports. Best Regards Soby Mathew > -----Original Message----- > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandeep > Tripathy via TF-A > Sent: 08 June 2020 10:34 > To: Olivier Deprez <Olivier.Deprez(a)arm.com>; tf-a(a)lists.trustedfirmware.org > Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC > > Hi Olivier, > > -----Original Message----- > > From: Olivier Deprez [mailto:Olivier.Deprez@arm.com] > > Sent: Monday, June 08, 2020 1:14 PM > > To: tf-a(a)lists.trustedfirmware.org; Sandeep Tripathy > > Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC > > > > Hi Sandeep, > > > > gicv3_end_of_interrupt_sel1 is a static access helper macro. Its > > naming precisely tells what it does at gicv3 module level. It is > > called from > the weak > > plat_ic_end_of_interrupt function for BL32 image. > > > > I tend to think it is the driver responsibility to ensure the module > interrupt > > acknowledge register write is reaching HW in order (or "be visible to > all > > observers"). > > The driver should be agnostic of what interrupt controller is used and its > behavior. > And since 'all' writes were to mmio ranges mapped Device(nGnRE) > /strongly-ordered(nGnRnE) > there was no such need. This is a special case for GICv3 system interface only. > Adding at driver level a DSB is unnecessary for other interrupt controllers. > > > Also I suspect adding a dsb might not be required generically for all > kind of IP. > > Here are you referring to the peripheral IP or interrupt controller IP ? > The issue is reordering at arm core itself (STR to device address Vs msr(sysreg > write)). > So I think Its applicable for all IP. > > > Adding a barrier in generic code might incur an unnecessary bottleneck. > > But if there is a need to *ensure* presence of at least one DSB between the > write transfer from core to device clear and gicv3 eoi icc register write in a > generic way then what other option we have. > > > > Thus wouldn't it be better to add the barrier to the overridden > > platform function rather than in generic gicv3 code? > > That can be done but I feel this is more to do with gicv3 system interface only. > Inside plat_xxx one has to check #if GICV3 ...and system interface. > > > > I have a put a comment in the review, we can continue the discussion > there. > > > > Regards, > > Olivier. > > > Thanks > Sandeep > > ________________________________________ > > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of > > Sandeep Tripathy via TF-A <tf-a(a)lists.trustedfirmware.org> > > Sent: 05 June 2020 19:43 > > To: tf-a(a)lists.trustedfirmware.org > > Subject: [TF-A] GICV3: system interface EOI ordering RFC > > > > Hi, > > In a typical interrupt handling sequence we do 1-Read IAR > > 2-Do interrupt handling > > 3-Clear the interrupt at source , so that the device de-asserts IRQ > request to > > GIC > > >> I am suggesting a need of DSB here in case of GICv3 +. > > 4-Write to GIC cpu interface to do EOI. > > > > Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write > > over > AMBA > > interface. The > > Addresses are mapped with (nR) attribute. Hence the write transfers > from the > > core will be > > generated at step 3 and 4 in order. Please ignore the additional > buffers/bridges > > in path from > > core till peripheral which has to be dealt separately as per SOC. > > > > Query: I understand GICv3 system interface accesses are not over this > protocol > > and core will not > > follow the ordering rule ? > > > > I have observed spurious interrupt issue/manifestation ( I don't have > the > > transfers probed) in > > RTOS environment where I have a primitive GICv3 driver but I wonder > > why things does not fail in Linux or tf-a. If it is working because > > from step(3) to > step(4) we have > > barriers by chace > > due to other device register writes then I would suggest to have one > > in > the EOI > > clearing API itself. > > > > RFC: > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454 > > > > Thanks > > Sandeep > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 4 months

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Re: [TF-A] GICV3: system interface EOI ordering RFC

by Olivier Deprez

Hi Sandeep, gicv3_end_of_interrupt_sel1 is a static access helper macro. Its naming precisely tells what it does at gicv3 module level. It is called from the weak plat_ic_end_of_interrupt function for BL32 image. I tend to think it is the driver responsibility to ensure the module interrupt acknowledge register write is reaching HW in order (or "be visible to all observers"). Also I suspect adding a dsb might not be required generically for all kind of IP. Adding a barrier in generic code might incur an unnecessary bottleneck. Thus wouldn't it be better to add the barrier to the overridden platform function rather than in generic gicv3 code? I have a put a comment in the review, we can continue the discussion there. Regards, Olivier. ________________________________________ From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Sandeep Tripathy via TF-A <tf-a(a)lists.trustedfirmware.org> Sent: 05 June 2020 19:43 To: tf-a(a)lists.trustedfirmware.org Subject: [TF-A] GICV3: system interface EOI ordering RFC Hi, In a typical interrupt handling sequence we do 1-Read IAR 2-Do interrupt handling 3-Clear the interrupt at source , so that the device de-asserts IRQ request to GIC >> I am suggesting a need of DSB here in case of GICv3 +. 4-Write to GIC cpu interface to do EOI. Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write over AMBA interface. The Addresses are mapped with (nR) attribute. Hence the write transfers from the core will be generated at step 3 and 4 in order. Please ignore the additional buffers/bridges in path from core till peripheral which has to be dealt separately as per SOC. Query: I understand GICv3 system interface accesses are not over this protocol and core will not follow the ordering rule ? I have observed spurious interrupt issue/manifestation ( I don’t have the transfers probed) in RTOS environment where I have a primitive GICv3 driver but I wonder why things does not fail in Linux or tf-a. If it is working because from step(3) to step(4) we have barriers by chace due to other device register writes then I would suggest to have one in the EOI clearing API itself. RFC: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454 Thanks Sandeep

5 years, 4 months

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Re: [TF-A] RK3399_BAUDRATE default value

by Heiko Stübner

Hi Walter, Am Freitag, 5. Juni 2020, 22:45:25 CEST schrieb Walter Lozano via TF-A: > I have noticed that default baudrate for rk3399 board RK3399_BAUDRATE > defined in plat/rockchip/rk3399/rk3399_def.h is 115200 while U-boot > default value and most documentation points to a value of 1500000 for > console. console baudrate on rk3399 differ a lot between boards. There are a number using the 1.5MHz and another big number using 115200 (including but not limited to the ChromeOS devices from the Gru line). Hence we have the code that selects the actual baudrate from the devicetree attached by u-boot when calling TF-A. So I guess it should stay as it is right now. Heiko > This of course means that messages printed by ATF are not visible by > default in this context. > > The change from 1500000 to 115200 was introduced in > 0c05748bdebfad9fa43a80962186438bb8fbce62, > > https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=0c05… > > with the following message > > commit 0c05748bdebfad9fa43a80962186438bb8fbce62 > Author: Caesar Wang <wxt(a)rock-chips.com> > Date: Tue Apr 19 20:42:17 2016 +0800 > > rockchip: fixes for the required > > This patch has the following change for rk3399. > > * Set the uart to 115200 since the loader decide to set > uart baud to 115200Hz. So the ATF also should set uart baud to 115200. > [..] > > However, I'm not sure it this still applies. > > I'll be happy to submit a patch to update the value if it is OK. > > Regards, > > Walter > >

5 years, 4 months

1
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RK3399_BAUDRATE default value

by Walter Lozano

I have noticed that default baudrate for rk3399 board RK3399_BAUDRATE defined in plat/rockchip/rk3399/rk3399_def.h is 115200 while U-boot default value and most documentation points to a value of 1500000 for console. This of course means that messages printed by ATF are not visible by default in this context. The change from 1500000 to 115200 was introduced in 0c05748bdebfad9fa43a80962186438bb8fbce62, https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=0c05… with the following message commit 0c05748bdebfad9fa43a80962186438bb8fbce62 Author: Caesar Wang <wxt(a)rock-chips.com> Date: Tue Apr 19 20:42:17 2016 +0800 rockchip: fixes for the required This patch has the following change for rk3399. * Set the uart to 115200 since the loader decide to set uart baud to 115200Hz. So the ATF also should set uart baud to 115200. [..] However, I'm not sure it this still applies. I'll be happy to submit a patch to update the value if it is OK. Regards, Walter

5 years, 4 months

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GICV3: system interface EOI ordering RFC

by Sandeep Tripathy

Hi, In a typical interrupt handling sequence we do 1-Read IAR 2-Do interrupt handling 3-Clear the interrupt at source , so that the device de-asserts IRQ request to GIC >> I am suggesting a need of DSB here in case of GICv3 +. 4-Write to GIC cpu interface to do EOI. Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write over AMBA interface. The Addresses are mapped with (nR) attribute. Hence the write transfers from the core will be generated at step 3 and 4 in order. Please ignore the additional buffers/bridges in path from core till peripheral which has to be dealt separately as per SOC. Query: I understand GICv3 system interface accesses are not over this protocol and core will not follow the ordering rule ? I have observed spurious interrupt issue/manifestation ( I don’t have the transfers probed) in RTOS environment where I have a primitive GICv3 driver but I wonder why things does not fail in Linux or tf-a. If it is working because from step(3) to step(4) we have barriers by chace due to other device register writes then I would suggest to have one in the EOI clearing API itself. RFC: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454 Thanks Sandeep

5 years, 4 months

1
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Re: [TF-A] Slides for recent TF-A Forums

by Joanna Farley

Hi Okash, These are generally provided on https://www.trustedfirmware.org/meetings/tf-a-technical-forum/ however they are missing from 7th May onwards at the moment. I have an update pending approval on tf.org for adding the details of that session and then I need to add the information from the session on 21st May and the session yesterday. Joanna From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Okash Khawaja via TF-A <tf-a(a)lists.trustedfirmware.org> Reply to: Okash Khawaja <okash.khawaja(a)gmail.com> Date: Friday, 5 June 2020 at 11:29 To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org> Subject: [TF-A] Slides for recent TF-A Forums Hi, Where can I find slides for recent TF-A Forum presentations? Thanks, Okash

5 years, 4 months

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Slides for recent TF-A Forums

by Okash Khawaja

Hi, Where can I find slides for recent TF-A Forum presentations? Thanks, Okash

5 years, 4 months

1
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Re: [TF-A] Gerrit seems to be broken

by Madhukar Pappireddy

Hi Bill, I continue to the error while trying to invoke “Allow-CI” or other votes as part of gerrit review. I tried multiple browsers as well and logged out before attempting again. Thanks, Madhu From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Bill Fletcher via TF-A Sent: Tuesday, June 2, 2020 12:13 PM To: Varun Wadekar <vwadekar(a)nvidia.com> Cc: tf-a(a)lists.trustedfirmware.org Subject: Re: [TF-A] Gerrit seems to be broken Hi Varun, Do you still see the problem? It has been reported before. Regards Bill On Tue, 2 Jun 2020 at 18:01, Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>> wrote: Hello, The TF gerrit review dashboard seems to be broken this morning. I see “Server error” and it does not allow me to post scores or comments. Tried different browsers, but same issue persists. Anyone else seeing the same problem? Is this is a known issue? If yes, is anyone working on it? -Varun -- TF-A mailing list TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org> https://lists.trustedfirmware.org/mailman/listinfo/tf-a -- [Image removed by sender. Linaro]<http://www.linaro.org/> Bill Fletcher | Field Engineering T: +44 7833 498336<tel:+44+7833+498336> bill.fletcher(a)linaro.org<mailto:bill.fletcher@linaro.org> | Skype: billfletcher2020

5 years, 5 months

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Re: [TF-A] Gerrit seems to be broken

by Bill Fletcher

Hi Varun, Do you still see the problem? It has been reported before. Regards Bill On Tue, 2 Jun 2020 at 18:01, Varun Wadekar via TF-A < tf-a(a)lists.trustedfirmware.org> wrote: > Hello, > > > > The TF gerrit review dashboard seems to be broken this morning. I see > “Server error” and it does not allow me to post scores or comments. Tried > different browsers, but same issue persists. > > > > Anyone else seeing the same problem? Is this is a known issue? If yes, is > anyone working on it? > > > > -Varun > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a > -- [image: Linaro] <http://www.linaro.org/> *Bill Fletcher* | *Field Engineering* T: +44 7833 498336 <+44+7833+498336> bill.fletcher(a)linaro.org | Skype: billfletcher2020

5 years, 5 months

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Re: [TF-A] Gerrit seems to be broken

by Joanna Farley

Working for me, the main and additional dashboards. https://review.trustedfirmware.org/admin/repos/TF-A/trusted-firmware-a,dash… I posted comments earlier ok as well. Joanna From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org> Reply to: Varun Wadekar <vwadekar(a)nvidia.com> Date: Tuesday, 2 June 2020 at 18:02 To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org> Subject: [TF-A] Gerrit seems to be broken Hello, The TF gerrit review dashboard seems to be broken this morning. I see “Server error” and it does not allow me to post scores or comments. Tried different browsers, but same issue persists. Anyone else seeing the same problem? Is this is a known issue? If yes, is anyone working on it? -Varun

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Gerrit seems to be broken

by Varun Wadekar

Hello, The TF gerrit review dashboard seems to be broken this morning. I see "Server error" and it does not allow me to post scores or comments. Tried different browsers, but same issue persists. Anyone else seeing the same problem? Is this is a known issue? If yes, is anyone working on it? -Varun

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TF-A Tech Forum Agenda @ Thr 4th June 2020 17:00-1800 BST

by Joanna Farley

Hi All, The next TF-A Tech Forum is scheduled for Thu 4th June 2020 17:00 - 18:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know. Agenda: * TF-A SMC fuzzing module overview - Presented by Mark Dykes * General explanation of the approach taken to randomize the type and timing of the SMC calls in TF-A to provide a Fuzz testing capability. * Optional TF-A Mailing List Topic Discussions Thanks Joanna

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Re: [TF-A] Unhandled Exception at EL3 in BL31 for Neoverse N1 with direct connect of DSU

by Manish Badarkhe

Hi Andrzej I think recent patch: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3493 which is currently in review may be solution for your issue where SCU presence is being checked before accessing CLUSTERCFR_EL1 register. Thanks Manish Badarkhe From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of "Witkowski, Andrzej via TF-A" <tf-a(a)lists.trustedfirmware.org> Reply to: "Witkowski, Andrzej" <andrzej.witkowski(a)intel.com> Date: Monday, 1 June 2020 at 19:38 To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org> Cc: "Witkowski, Andrzej" <andrzej.witkowski(a)intel.com>, "Lessnau, Adam" <adam.lessnau(a)intel.com> Subject: [TF-A] Unhandled Exception at EL3 in BL31 for Neoverse N1 with direct connect of DSU Hi, I work on project which uses ARM CPU Neoverse N1 with direct connect of DSU. I noticed the following error “Unhandled Exception at EL3” in BL31 bootloader after switching from ATF 2.1 to 2.2. The root cause is that after invoking neoverse_n1_errata-report function in lib/cpus/aarch64/neoverse_n1.S file and reaching the line 525, the function check_errata_dsu_934 in lib/cpus/aarch64/dsu_helpers.S file is always invoked regardless of whether ERRATA_DSU_936184 is set to 0 or to 1. In our case, ERRATA_DSU_936184 := 0. [cid:image001.png@01D6384E.C183C050] [cid:image002.png@01D6384E.C183C050] Neoverse N1 with direct connect version of DSU doesn’t contain SCU/L3 cache and CLUSTERCFR_EL1 register. The error “Unhandled Exception at EL3” appears in BL31 bootloader during attempt to read the CLUSTERCFR_EL1 register which doesn’t exist in our RTL HW. Andrzej Witkowskie Intel Technology Poland --------------------------------------------------------------------- Intel Technology Poland sp. z o.o. ul. Słowackiego 173 | 80-298 Gdańsk | Sąd Rejonowy Gdańsk Północ | VII Wydział Gospodarczy Krajowego Rejestru Sądowego - KRS 101882 | NIP 957-07-52-316 | Kapitał zakładowy 200.000 PLN. Ta wiadomość wraz z załącznikami jest przeznaczona dla określonego adresata i może zawierać informacje poufne. W razie przypadkowego otrzymania tej wiadomości, prosimy o powiadomienie nadawcy oraz trwałe jej usunięcie; jakiekolwiek przeglądanie lub rozpowszechnianie jest zabronione. This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by others is strictly prohibited.

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Unhandled Exception at EL3 in BL31 for Neoverse N1 with direct connect of DSU

by Witkowski, Andrzej

Hi, I work on project which uses ARM CPU Neoverse N1 with direct connect of DSU. I noticed the following error "Unhandled Exception at EL3" in BL31 bootloader after switching from ATF 2.1 to 2.2. The root cause is that after invoking neoverse_n1_errata-report function in lib/cpus/aarch64/neoverse_n1.S file and reaching the line 525, the function check_errata_dsu_934 in lib/cpus/aarch64/dsu_helpers.S file is always invoked regardless of whether ERRATA_DSU_936184 is set to 0 or to 1. In our case, ERRATA_DSU_936184 := 0. [cid:image001.png@01D63828.FA4B1440] [cid:image002.png@01D6382A.B84A0950] Neoverse N1 with direct connect version of DSU doesn't contain SCU/L3 cache and CLUSTERCFR_EL1 register. The error "Unhandled Exception at EL3" appears in BL31 bootloader during attempt to read the CLUSTERCFR_EL1 register which doesn't exist in our RTL HW. Andrzej Witkowskie Intel Technology Poland --------------------------------------------------------------------- Intel Technology Poland sp. z o.o. ul. Sowackiego 173 | 80-298 Gdask | Sd Rejonowy Gdask Pnoc | VII Wydzia Gospodarczy Krajowego Rejestru Sdowego - KRS 101882 | NIP 957-07-52-316 | Kapita zakadowy 200.000 PLN. Ta wiadomo wraz z zacznikami jest przeznaczona dla okrelonego adresata i moe zawiera informacje poufne. W razie przypadkowego otrzymania tej wiadomoci, prosimy o powiadomienie nadawcy oraz trwae jej usunicie; jakiekolwiek przegldanie lub rozpowszechnianie jest zabronione. This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by others is strictly prohibited.

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Announcing new maintainers for the TF-A project

by Sandrine Bailleux

Hi all, Now that the tf.org project maintenance process [1] has been finalized, it is time to think about electing new maintainers for the project. We are delighted to announce that the following contributors have been appointed maintainers by their peers: - Julius Werner (Google) - Varun Wadekar (NVIDIA) - Andre Przywara (Arm) - Lauren Wehrmeister (Arm) - Madhukar Pappireddy (Arm) As outlined in [1], here is the definition and responsibilities of maintainers: ------------8<------------ There are a number of maintainers assigned to the project. The project keeps a list of them along with their contact information. Maintainers don't necessarily need a deep domain expertise of all areas of the project, instead they look at the project from a high level perspective. They are expected to ensure that changes adhere to the project's quality criteria, to its architectural direction, to its threat model and so on. Code owners and maintainers are complementary roles. Unlike code owners, maintainers can approve any patch, no matter what module it concerns. They are responsible for ensuring patches have had enough overall review and adding their own approval in a timely manner. They also have merge rights, i.e. the ability to merge a patch in the tree once it has received all required approvals. ------------8<------------ These people have been granted Code-Review -2/+2 rights in Gerrit and have been added in the maintainers.rst file as part of this patch: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4298 Congratulations to them! Best regards, Sandrine [1] https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…

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Re: [TF-A] After migrating from TFA-1.5 to TFA2.3, parts of NOTICE messages are missed, which comes as part of boot-up logs.

by Manish Pandey2

Hi Pankaj, Can you please send the specific NOTICE messages which are missing, may be sending 1.5 and 2.3 logs will help. thanks Manish ________________________________ From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Pankaj Gupta via TF-A <tf-a(a)lists.trustedfirmware.org> Sent: 27 May 2020 09:36 To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org> Subject: [TF-A] After migrating from TFA-1.5 to TFA2.3, parts of NOTICE messages are missed, which comes as part of boot-up logs. Hi After migrating from TFA-1.5 to TFA2.3, parts of NOTICE messages are missed, which comes as part of boot-up logs. Any pointers on how to fix this issue. Thanks. Regards Pankaj

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After migrating from TFA-1.5 to TFA2.3, parts of NOTICE messages are missed, which comes as part of boot-up logs.

by Pankaj Gupta

Hi After migrating from TFA-1.5 to TFA2.3, parts of NOTICE messages are missed, which comes as part of boot-up logs. Any pointers on how to fix this issue. Thanks. Regards Pankaj

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Re: [TF-A] fconf: Validating config data

by Manish Badarkhe

Hi Raghu We have plan to work on this and come up with some design which handles mandatory/critical properties. On 13/05/2020, 22:18, "TF-A on behalf of Raghu K via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote: Hi All, Since the 2.3 release is done, can we revisit this topic? I think we left this with finalizing on how to handle bad/incorrect DTB's. Sandrine's latest proposal below: "A bad DTB seems more like an integration error than a programming error to me, and thus should be handled with runtime checks according to the current guidelines. Incorrect values for mandatory properties should probably be treated as unrecoverable errors (causing a panic) and incorrect/missing optional properties as recoverable errors (issuing a warning message)." I agree with this proposal and think we should follow this. This addresses my original concern of handling errors consistently and being safe by verifying mandatory/critical properties at run-time. Thoughts ? Thanks Raghu On 4/13/20 10:27 AM, Raghu Krishnamurthy wrote: > Thanks Sandrine. Revisiting after v2.3 is sounds fine. > > -Raghu > > On 4/10/20 2:25 AM, Sandrine Bailleux wrote: >> Hi Raghu, >> >> On 4/8/20 12:50 AM, Raghu Krishnamurthy wrote: >>> Thanks Sandrine, Louis, >>> >>> Agree with both of you. I'm fine with using asserts or panics, as >>> long as we uniformly use it. The change i sent out(review 3845) was >>> because i noticed inconsistency in handling errors. If we do use >>> asserts, all code that checks for mandatory properties, should be >>> changed to assert as opposed to return error code. For optional >>> properties, we can continue to return an error code or print >>> warnings etc. >> >> Yes, I too think consistency is key here. As you said, we need to >> settle on the expected behaviour and enforce it uniformly across the >> fconf code. Let's revisit this code after the v2.3 release. >> >>> I would like to point out that using asserts here is different from >>> what is documented in the coding guidelines. The guidelines >>> explicitly spells out using asserts for "programming errors". >>> Now, is having a bad DTB considered a programming error? ;) The DTB >>> is platform data as opposed to code. The guidelines might need to be >>> updated based on the conclusion here. >> >> Now that you point it out, and after taking a closer look at [1], I >> think I was wrong. A bad DTB seems more like an integration error >> than a programming error to me, and thus should be handled with >> runtime checks according to the current guidelines. Incorrect values >> for mandatory properties should probably be treated as unrecoverable >> errors (causing a panic) and incorrect/missing optional properties as >> recoverable errors (issuing a warning message). >> >> [1] >> https://trustedfirmware-a.readthedocs.io/en/latest/process/coding-guideline… >> >> >>> Also note the couple of scenarios i mentioned in an earlier email. >>> Platforms like RPI4 don't generally enable TBBR and the DTB image >>> could get corrupt or be modified on purpose. On a release build, >>> this could cause silent corruption. Panic() would avoid this. >>> >>> In any case, it would be good to settle on the expected behavior for >>> each of these abnormal cases. I don't have a strong preference for >>> asserts or panics here, since each has its pros and cons as both of >>> you called out. >>> >>> Thanks >>> Raghu > -- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a

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TF-A Tech Forum Agenda @ Thr 21sth May 2020 17:00-1800 BST

by Joanna Farley

Hi All, The next TF-A Tech Forum is scheduled for Thu 21st May 2020 17:00 - 18:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know. Agenda: * Firmware Configuration Framework (FConf) Update - Presented by Manish Badarkhe and Madhukar Pappireddy * Discussion on how we have leveraged FConf framework in making statically configured components of TF-A to be dynamic. A number of such components have already been identified which potentially use FConf framework. Patches for such components are either merged or in-review * Design discussion on CoT descriptors movement to device tree using FConf framework. * Optional TF-A Mailing List Topic Discussions Thanks Joanna

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Re: [TF-A] Candidates for fconf based dynamic configuration

by Raghu K

Off the top of my head, secure world interrupts(SPI's, PPI's, SGI's), MMU mappings for anything that does not depend on image layout(platform specific devices, UEFI MM or other special regions), security policies like TZC region protections. -Raghu On 5/14/20 8:45 AM, Madhukar Pappireddy via TF-A wrote: > > Hi, > > We are in the process of leveraging the fconf framework to make the > static configurations of various components of TF-A to more dynamic > configurations. The primary motivation behind this effort is to > evaluate the possibility of having common TF-A BL images that can be > used across multiple platforms. As a start, this involves moving > compile-time C based data structures into device tree which are > extracted during runtime. We have chosen the FVP platform as a proof > of concept for this effort and have identified the following > components to be made more dynamic: > > runtime UART std-out: > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3775, > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3923/ > > Topology description: > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3492, > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3522 > > GICv3 configuration: > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4066 > > Timer configuration: > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3696 > > SDEI platform setup: > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3990 > > CoT descriptor: > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4080, > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4081 > > Platform IO Policies: > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2558 > > Please advise if there are any other components of TF-A that can be > configured dynamically in runtime. > > Thanks, > > Madhu > >

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Candidates for fconf based dynamic configuration

by Madhukar Pappireddy

Hi, We are in the process of leveraging the fconf framework to make the static configurations of various components of TF-A to more dynamic configurations. The primary motivation behind this effort is to evaluate the possibility of having common TF-A BL images that can be used across multiple platforms. As a start, this involves moving compile-time C based data structures into device tree which are extracted during runtime. We have chosen the FVP platform as a proof of concept for this effort and have identified the following components to be made more dynamic: runtime UART std-out: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3775, https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3923/ Topology description: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3492, https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3522 GICv3 configuration: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4066 Timer configuration: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3696 SDEI platform setup: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3990 CoT descriptor: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4080, https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4081 Platform IO Policies: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2558 Please advise if there are any other components of TF-A that can be configured dynamically in runtime. Thanks, Madhu

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Re: [TF-A] TF-A and U-Boot: How to Boot a specific u-boot image

by Raghu K

Hi Florian, I can give some general answers to your questions and hopefully get to answering your real questions with further discussion. Please feel free to ask more questions if this does not help. >> I noticed that TF-A is designed to load FIP Image but the U-Boot Environment have a different format. How to access the QSPI NOR memory? NXP specific driver? [RK] TF-A generally provides frameworks to do most things and does not provide device specific drivers but for SPI NOR, there are drivers under drivers/mtd/nor that could potentially be used. You will likely need to implement the appropriate platform hooks for the SPI bus itself to use it. The TF-A IO framework has the io_mtd layer that can be hooked into a nor device. drivers/st/spi/stm32_qspi.c seems to use all of this and should be a good example(perhaps some one from ST can chime in too). if you hook you SPI driver to the TF-A layers correctly, there should be nothing preventing you from accessing the uboot environment partition. Also, TF-A's primary/default format for firmware images is FIP but definitely does not preclude a platform from using it's own format. >>The bl2 is designed to load only one FIP image, is it possible to add an additional entry ? [RK] Not really. BL2 is fairly generic and you should be able to hook any image format to it. If you must use the FIP format, you can map your images to existing image id's to create a FIP with any image that you have. Once again, FIP is fairly flexible and generally treats firmware images in the package as blob's. >>if we want to use a secure boot in the future [RK] Like with the above things, the Trusted Board Boot framework is flexible and you should be able to implement secure boot on FIP and other formats. TF-A provides an implementation of the TBBR specification for secure boot. It should be possible to implement the algorithm below, if you have an appropriate platform port, from what i gather in your question below. Thanks -Raghu On 5/13/20 5:40 AM, florian.manoel--- via TF-A wrote: > > Hello TF-A mail list, > > I’m new here, so I quickly introduce myself. > I am Florian Manoel, working as firmware developer at Siemens in > Karlsruhe, Germany. Recently, we decided to start some development > based on ARM processor, the theme TF-A is new for us. > > Currently, we have a custom board equipped with the processor NXP > Layerscape LS1043a. So far, everything is working as planned, the > PreBootLoader (TF-A) boots the bootloader (U-Boot) that’s boots linux > on top. > However, we want to have the possibility to boot an alternative u-boot > FIP image, I explain: > We use as boot source a QSPI NOR memory. In this memory are stored > ‘bl2_qspi.pbl’, 2 times ‘fip.bin’, the u-boot environment and some > micro-code. > We want to select the u-boot image to be booted according to the value > of a specific variable stored in the u-boot environment ‘u-boot-select’. > The algo is, for my eye, relatively simple : > > Start > - Check value of the u-boot variable ‘u-boot-select’ > > - Check if the corresponding u-boot image is valid, if not select the > alternative one > - Boot selected u-boot image > End > > > We want this functionality in case an u-boot image is broken (ex: > power OFF during U-Boot update). > > I already went through the source code and it rose more question than > it answered. For example: > I noticed that TF-A is designed to load FIP Image but the U-Boot > Environment have a different format. How to access the QSPI NOR > memory? NXP specific driver? > The bl2 is designed to load only one FIP image, is it possible to add > an additional entry ? > On top of it come the question of the reliability and what will happen > if we want to use a secure boot in the future.. > > I am looking for advice and support on this specific topic. > Thanks for your support, > > Mit freundlichen Grüßen > Florian Manoël > > Siemens AG > Digital Industries > Process Automation > Software House Khe > DI PA CI R&D 2 > Östliche Rheinbrückenstr. 50 > 76187 Karlsruhe, Deutschland > Tel.: +49 721 595-1433 > mailto:florian.manoel@siemens.com > www.siemens.com/ingenuityforlife <https://siemens.com/ingenuityforlife> > > Siemens Aktiengesellschaft: Vorsitzender des Aufsichtsrats: Jim > Hagemann Snabe; Vorstand: Joe Kaeser, Vorsitzender; Roland Busch, > Klaus Helmrich, Cedrik Neike, Ralf P. Thomas; Sitz der Gesellschaft: > Berlin und München, Deutschland; Registergericht: Berlin > Charlottenburg, HRB 12300, München, HRB 6684; WEEE-Reg.-Nr. DE 23691322 > >

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Re: [TF-A] fconf: Validating config data

by Sandrine Bailleux

Hi Raghu and Louis, On 4/7/20 12:14 PM, Louis Mayencourt via TF-A wrote: > I do agree with you: case 2 and 3 are similar (wrongly formed DTB) and > should lead to the same behavior. > > A mandatory property miss or a hit with a structurally incorrect node > means that the DTB doesn't follow the provided binding document. Such a > DTB shouldn't be considered as valid and should trigger a build failure > and/or a code panic. That's what still confuses me... Agree on cases 2 and 3 triggering a build failure if possible, but not a code panic. A code panic stays in a release build. With what we've been discussing so far, it would seem more appropriate to me to have debug assertions to catch cases 2 and 3. These debug assertions can help catching structural problems in the DTB during the development phase and can be eliminated for a production build, leaving no checks whatsoever in the code. This is the strategy we've been using so far in TF-A. For lots of platform interfaces, the generic code includes debug assertions to check the correct implementation of these interfaces by platform integrators. For example, checking the range of their return values. I would say this is deeply embedded into the threat model TF-A uses today. See https://trustedfirmware-a.readthedocs.io/en/latest/process/coding-guideline… On one hand, it makes sense to me. On the other hand, I take Raghu's point that it would be unrealistic to assume that 100% of code has been covered by tests. This is very hard to achieve in practice, especially to cover all error cases ; thus, it seems utopian to assume that all debug assertions have been exercised during development and can be safely removed. TF-A does provide a way to keep debug assertions in a release build (using the ENABLE_ASSERTIONS build flag) if platform integrators judge they would rather keep them but this is not the default behaviour. Regards, Sandrine

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TF-A and U-Boot: How to Boot a specific u-boot image

by florian.manoel＠siemens.com

Hello TF-A mail list, I'm new here, so I quickly introduce myself. I am Florian Manoel, working as firmware developer at Siemens in Karlsruhe, Germany. Recently, we decided to start some development based on ARM processor, the theme TF-A is new for us. Currently, we have a custom board equipped with the processor NXP Layerscape LS1043a. So far, everything is working as planned, the PreBootLoader (TF-A) boots the bootloader (U-Boot) that's boots linux on top. However, we want to have the possibility to boot an alternative u-boot FIP image, I explain: We use as boot source a QSPI NOR memory. In this memory are stored 'bl2_qspi.pbl', 2 times 'fip.bin', the u-boot environment and some micro-code. We want to select the u-boot image to be booted according to the value of a specific variable stored in the u-boot environment 'u-boot-select'. The algo is, for my eye, relatively simple : Start - Check value of the u-boot variable 'u-boot-select' - Check if the corresponding u-boot image is valid, if not select the alternative one - Boot selected u-boot image End We want this functionality in case an u-boot image is broken (ex: power OFF during U-Boot update). I already went through the source code and it rose more question than it answered. For example: I noticed that TF-A is designed to load FIP Image but the U-Boot Environment have a different format. How to access the QSPI NOR memory? NXP specific driver? The bl2 is designed to load only one FIP image, is it possible to add an additional entry ? On top of it come the question of the reliability and what will happen if we want to use a secure boot in the future.. I am looking for advice and support on this specific topic. Thanks for your support, Mit freundlichen Grüßen Florian Manoël Siemens AG Digital Industries Process Automation Software House Khe DI PA CI R&D 2 Östliche Rheinbrückenstr. 50 76187 Karlsruhe, Deutschland Tel.: +49 721 595-1433 mailto:florian.manoel@siemens.com www.siemens.com/ingenuityforlife<https://siemens.com/ingenuityforlife> Siemens Aktiengesellschaft: Vorsitzender des Aufsichtsrats: Jim Hagemann Snabe; Vorstand: Joe Kaeser, Vorsitzender; Roland Busch, Klaus Helmrich, Cedrik Neike, Ralf P. Thomas; Sitz der Gesellschaft: Berlin und München, Deutschland; Registergericht: Berlin Charlottenburg, HRB 12300, München, HRB 6684; WEEE-Reg.-Nr. DE 23691322

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Impact of the tf.org projects' maintenance process on TF-A

by Sandrine Bailleux

Hello all, As the trustedfirmware.org project maintenance process [1] is now live, it would be good if we start adopting it in our development flow for TF-A. I would like to highlight the main changes that will have an impact on our day-to-day work on the project. 1. Patch submitters to explicit choose their reviewers ------------------------------------------------------ All patches should now have dedicated reviewers. The patch submitter is responsible for adding them in the reviewers field of their Gerrit review. Each patch should have 2 types of reviewers: - Code owners. - Maintainers. There needs to be 1 code owner per module modified by the patch as well as 1 maintainer. The maintainers and code owners are listed here: https://trustedfirmware-a.readthedocs.io/en/latest/about/maintainers.html Ideally, we would have at least 2 code owners per module so that they can review each other's patches. Unfortunately we're not there yet (especially for platform ports) so we need a work around for patches submitted by the sole code owner of a module itself. In this scenario, I would like to suggest we leave it to the patch submitter to decide on a case by case basis whether they want to nominate someone to do the detailed technical review or skip it entirely. In any case, a maintainer will still need to review and approve the patch. If this proves not to be working well over time (either because it creates unnecessary review bottlenecks or lowers the code quality too much), we can revisit that in the future. If you've got patches in review right now, may I please request you to add reviewers accordingly? The sooner we start adopting this process the better, as it will allow us to see how this works in practice and come up with adjustments if need be. 2. Reviewers to provide feedback in a timely manner --------------------------------------------------- If someone asks you to do a review, please try to do it in a timely manner. There is no timeline guidelines set just yet for TF-A but I think a good rule of thumb would be to aim to provide feedback in a week's time. This does not mean that the review has to be completed in a week (complex patches might need a lot of discussion and/or rounds of review & rework), just that there's some progress and activity at least once per week. If for some reason, you know you won't be able to honour a review request, please say so on Gerrit ASAP so that the patch submitter can choose another reviewer. 3. What's next? --------------- In the coming weeks or months, we'd like to: - Extend the list of code owners. - Extend the list of maintainers. - Come up with TF-A specific contribution guidelines that complement the tf.org process [1]. We already have some here [2] but would like to expand them and possibly revisit some of them. Obviously, this will be a community effort, much like the tf.org process was, and all TF-A contributors will have a say in defining this so that we end up with something that works for everyone (as much as possible). Best regards, Sandrine [1] https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p… [2] https://trustedfirmware-a.readthedocs.io/en/latest/process/contributing.html

5 years, 5 months

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Re: [TF-A] GCC compiler flags

by Samuel Holland

Hi, On 5/12/20 1:41 PM, Varun Wadekar via TF-A wrote: > While reviewing all the compiler flags used by TF-A, we couldn’t find > information for the following options in the GCC manual [1] > > * --fatal-warnings > (https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…) Options passed to -Wa are assembler options, not compiler options. That one is documented here: https://sourceware.org/binutils/docs/as/W.html > * -fno-stack-protector > (https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…) This is the negative version of -fstack-protector, needed on compilers configured with --enable-default-ssp: https://gcc.gnu.org/onlinedocs/gcc-10.1.0/gcc/Instrumentation-Options.html#… They are both valid. Regards, Samuel

5 years, 5 months

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GCC compiler flags

by Varun Wadekar

Hello, While reviewing all the compiler flags used by TF-A, we couldn't find information for the following options in the GCC manual [1] * --fatal-warnings (https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…) * -fno-stack-protector (https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…) Can someone please help me understand if these options are still valid? Thanks. [1] https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/Option-Index.html#Option-Index ----------------------------------------------------------------------------------- This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. -----------------------------------------------------------------------------------

5 years, 5 months

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Re: [TF-A] Project Maintenance Proposal for tf.org Projects

by Sandrine Bailleux

Hi all, On 5/5/20 9:04 AM, Sandrine Bailleux via TF-A wrote: > I've received very little feedback on version 2 of the proposal, which > hints that we are reaching an agreement. Thus, I plan to finalize the > proposal this week. This can then become part of our development flow > for all trustedfirmware.org projects. > > Thanks again for all the inputs! The project maintenance process is now live. The document has been moved here (with a few minor edits to turn it from a proposal to an effective process): https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p… Thanks! Regards, Sandrine

5 years, 5 months

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New Defects reported by Coverity Scan for ARM-software/arm-trusted-firmware

by scan-admin＠coverity.com

Hi, Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. 1 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan. New defect(s) Reported-by: Coverity Scan Showing 1 of 1 defect(s) ** CID 358027: Insecure data handling (TAINTED_SCALAR) ________________________________________________________________________________________________________ *** CID 358027: Insecure data handling (TAINTED_SCALAR) /common/fdt_wrappers.c: 295 in fdt_get_reg_props_by_name() 289 290 index = fdt_stringlist_search(dtb, node, "reg-names", name); 291 if (index < 0) { 292 return index; 293 } 294 >>> CID 358027: Insecure data handling (TAINTED_SCALAR) >>> Passing tainted variable "index" to a tainted sink. 295 return fdt_get_reg_props_by_index(dtb, node, index, base, size); 296 } 297 298 /******************************************************************************* 299 * This function gets the stdout path node. 300 * It reads the value indicated inside the device tree. ________________________________________________________________________________________________________ To view the defects in Coverity Scan visit, https://u2389337.ct.sendgrid.net/ls/click?upn=nJaKvJSIH-2FPAfmty-2BK5tYpPkl…

5 years, 5 months

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Re: [TF-A] Proposal for Measured Boot Implementation

by Vivek Prasad

Hello Stuart, Alexei, Chiming-in here on Ampere's behalf... We analysed this proposal internally. And we see a number issues with this, some of which was already raised by Raghu in the previous threads. Here is a summary of the main issues that we see. * Only supporting mbedtls, and this is fixed config at compile time. * We propose that there should be a variable for the algorithm to be used, which can be setup at initialization time. * This solution relies on taking the hash directly from the digest as the measurement, instead of the computed hash. This is not safe, especially considering measured boot may use a different hash bank, so digest hash may not be correct/valid. * Only measuring the BL2 image, per the ARM SBSG we must be measuring and logging *all* images/boot phases * BL31 * BL32 (all secure partitions) * BL33 (UEFI or any other non-secure boot loader) * Once we ERET into BL33, the measure boot flow continues and is owned by that boot loader * Only see support for PCR0, any/all unsigned config data must be logged to PCR1. * Passing PCRs to non-secure software before logging is not compliant with TCG Static-Root-of-Trust Measurement (SRTM) requirements * It was discussed before in separate conversations… especially in systems where you are talked about two different signing domains where BL33 is a different trust/signing domain. * BL33 should only do hash-log-extend… there is no need for BL33 to be aware of the current PCR value (beyond what is provided in the boot event log). * Based on comments on the mail thread, there seem to be bad assumptions/expectations around TPM accessibility from non-secure world. * Expecting SPI/I2C TPMs to be directly accessed from non-secure world instead of abstracting hardware details via the TCG CRB interface (which has been already standardized as the defacto mechanism for ARM on past mobile, client, and server solutions). * CRB will "just work" for Aptio/EDK2/Linux/Windows/Hyper-V/VMWare * NOTE: This goes back to what is a “productizable” TPM solution. We want it to be turn-key solution for customers without having to support/develop proprietary drivers. -Vivek/Harb

5 years, 5 months

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TF-A Tech Forum Agenda @ Thr 7th May 2020 17:00-1800 BST

by Joanna Farley

Hi All, The next TF-A Tech Forum is scheduled for Thu 7th May 2020 17:00 - 18:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know. This meeting will be chaired by Bipin Ravi. Agenda: * Overview of a new TF-A Build System based on Cmake by Javier Almansa Sobrino * Optional TF-A Mailing List Topic Discussions Thanks Joanna

5 years, 5 months

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Re: [TF-A] Need input on Errata implementation

by Soby Mathew

> -----Original Message----- > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghu > Krishnamurthy via TF-A > Sent: 30 April 2020 02:33 > To: Manish Badarkhe <Manish.Badarkhe(a)arm.com>; tf- > a(a)lists.trustedfirmware.org > Cc: nd <nd(a)arm.com> > Subject: Re: [TF-A] Need input on Errata implementation > > Hi Manish, > > Really appreciate you for taking time to respond to my concerns/questions. > > What about this situation? NS-EL2 makes an SMC call to EL3 to get some basic > information like GET_SOC_INFORMATION. This is a simple SMC and there is no > call to context save or context restore. During the SMC call, if there is a > speculative AT instruction on a lower EL(say NS-EL2), there could be a bad > cached translation. Do you not need to apply the errata in this situation ? If > not, why? > > >>We can't simply apply this errata on reset and just leave the system. > > [RK]Totally agree. See CPU_E_HANDLER_FUNC. It is not necessary that > cpu_ops are only called during reset and power down. > CPU_E_HANDLER_FUNC is called at runtime due EA's. > > >>We thought of taking different approach for this errata > implementation >>where anybody disable this workaround using macro as > this errata is >>applicable for most of the CPUs (by default enabled) and can't > be >>placed in cpu_ops. > > [RK]This is a poor approach in my view. Most CPU's is not all CPU's. The reason > the errata framework exists is to apply CPU specific erratas by checking for > them dynamically. Different stepping's of the same CPU's may or may not have > the errata and typically you check the MIDR to know if the errata applies or > not. Linux does not apply the errata to all CPU's since "most" CPU's have the > issue. They check for its existence at runtime and only then apply it. TF-A > should not hold itself to a lower standard. Hi Raghu I guess this depends on what the errata workaround involves. Since this workaround applies bit setting on an out of context register, it was not expected to affect the EL3 execution performance (or the lower level EL because the bits are restored on return). Also it was thought that the act of searching through the list of compiled CPUs and checking if the workaround is applicable might be more detrimental than the unilateral application of the workaround for this case (assuming no extra barriers are added since the code path it is inserted in have them already later in the sequence). But I agree it is more elegant to have this coupled into CPU_OPS framework. I think Manish has some ideas for this. Best Regards Soby Mathew > > -Raghu > > On 4/29/20 1:35 AM, Manish Badarkhe wrote: > > Hi Raghu > > > > Just to add/correct one more thing from my previous emails that this errata > workaround proposed is > > applied to both normal and secure world switches to EL3. > > > > Thanks > > Manish Badarkhe > > > > On 29/04/2020, 12:25, "TF-A on behalf of Manish Badarkhe via TF-A" <tf-a- > bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> > wrote: > > > > Hi Raghu > > > > On 29/04/2020, 02:00, "Raghu K" <raghu.ncstate(a)icloud.com> wrote: > > > > Hi Manish, > > > > Thanks. > > > > >> we don’t have any AT instances in minimum execution window after > context switching from S-EL(1/2) > > >> to EL3 and before updating TCR register. > > > > 1) What is the minimum execution window? Does that not change based > on micro-architecture? > > Not sure about exact minimum execution window. IMO, it really depend > upon when "context_save" gets called after > > entering into EL3 from S-EL1/2. It may changed upon micro-architecture. > Need some experts comment here. > > > > 2) Do we know that the "execution window" is exactly the same for all > the CPU's this errata applies to? > > It may be but we should not worry on that if we don’t have any AT > instruction execution in that window. > > > > Also, it appears we are only talking about switching from S-EL1/2 to EL3. > The same issue can happen when you go from NS-EL1/EL2 to EL3 as well. There > also seems to be an assumption in the patch you submitted that this errata > happens only during a so called context-switch. From my reading, the cortex- > Ax errata notices don't limit the errata to occur only during "context-switches" > in the "conditions" section and can occur while executing ANY code, although > the work around section does muddy the waters a bit. > > > > In Linux, at NS-EL2 this workaround is already in place. Hence we just > thought of considering cases from Secure EL side to put this workaround. > > Yes, errata should not limit to particular conditional section but this > particular errata is not straight-forward like another errata placed in the code > currently. We can't simply apply this errata on reset and just leave the system. > > > > Back to problem, AT instruction speculative execution using out-of- > context regime that results in page table walk and generate the incorrect > > translation which are cached in TLB. To avoid this issue we thought of > disabling PTW for that particular EL. > > for e.g. If AT instruction execution for EL1 present in EL3 then we have to > make sure speculative behaviour of this AT should not result in incorrect > translation cached in TLB. If system is always in EL3 (if we loop-in in EL3 always > without going back and forth to/from lower EL) then in that case > > there is no need of this workaround. > > Hence we thought to put this workaround over boundary context of > context switches. When "context save" (close to EL3 entry) happened we > meticulously save all EL system registers (S-EL1/S-EL2) with PTW disabled and > continue EL3 execution with PTW disabled ensuring we should not cache any > incorrect translation for (S-EL1/S-EL2) and during "context restore" (i.e. close > to EL3 exit) again we disabled PTW, restore all system registers for EL (S-EL1/S- > EL2) except TCR and then restore TCR. > > > > 3) Has there been any work done to actually reproduce this issue and > also to see that this actually fixes the issue? > > No this issue is hard to reproduce. > > > > 4) Has the CPU errata framework(cpu_ops etc.) been considered to > possibly implement the errata? Sprinkling erratas through common framework > code does not seem like a good idea. > > We thought of taking different approach for this errata implementation > where anybody disable this workaround using macro as this errata is > applicable for most of the CPUs (by default enabled) and can't be placed in > cpu_ops. > > > > Thanks > > Raghu > > > > Thanks > > Manish Badarkhe > > > > On 4/28/20 1:44 AM, Manish Badarkhe wrote: > > > Hi Raghu > > > > > > Please see my replies inline. > > > > > > Regards > > > Manish Badarkhe > > > > > > On 28/04/2020, 11:29, "Raghu Krishnamurthy" > <raghu.ncstate(a)icloud.com> wrote: > > > > > > Hi Manish, > > > > > > Understood. > > > > > > >>Hence before entering in EL3, we ensured that PTW is disabled > (at > > > context save) > > > > > > The context save and restore functions are executed in EL3. So how > are > > > you disabling PTW before entering EL3 ? > > > > > > Yes, I put it wrongly. We thought "context_save/restore" is best place > to disable PTW without much affecting the > > > code because we don’t have any AT instances in minimum execution > window after context switching from S-EL(1/2) > > > to EL3 and before updating TCR register. > > > > > > -Raghu > > > > > > Thanks > > > Manish Badarkhe > > > > > > On 4/27/20 10:53 PM, Manish Badarkhe wrote: > > > > Hi Raghu > > > > > > > > This workaround is specifically need for speculative AT instruction > behaviour in out of context regime. > > > > That means executing AT instruction for lower ELs (S-EL1/S-EL2) in > higher EL i.e. EL3. > > > > > > > > Behaviour of AT instruction is unaltered when it get executed in > same regime (when AT instruction executed for same EL > > > > where it is executing) and there is no possibility to execute AT > instruction for higher EL in lower EL. > > > > > > > > Hence before entering in EL3, we ensured that PTW is disabled (at > context save) and restore PTW back during > > > > exit of EL3. (at context restore). > > > > > > > > Thanks > > > > Manish Badarkhe > > > > > > > > On 28/04/2020, 01:23, "Raghu K" <raghu.ncstate(a)icloud.com> > wrote: > > > > > > > > Hi Manish, > > > > > > > > >>Hence proposed solution will work as it is > > > > > > > > [RK]If you are sure go ahead. I'm not convinced, but that may > be because > > > > i don't understand the errata fully/correctly. > > > > > > > > >>This workaround is very specific during context switching > > > > > > > > [RK] Context switching has many meanings depending on the > context(OS, > > > > hypervisor, TF-A world switch etc). The errata document i saw > does not > > > > elaborate on this. Perhaps clarifying this will help understand > why the > > > > solution you proposed will work. > > > > > > > > The solution below in points 2 and 3 have the same problem on > entry and > > > > exit, mentioned in my first email. Before you call > > > > el1_sysregs_context_save, an AT instruction could have > speculatively > > > > executed through speculation of branches that occur BEFORE > you call this > > > > function, when TCR still has the enable bit set. The fact that you > don't > > > > have an AT instruction in the context save routine or any > routine for > > > > that matter, does not guarantee that the hardware did not > speculate > > > > through some other means to reach an AT instruction. The > same applies to > > > > the context_restore routines. There is no guarantee right after > you > > > > finish the restore routing(and hence TCR has the enable bit set), > that > > > > the CPU cannot speculate to an AT instruction. > > > > So i'm not clear how you can say for certain that there was no > > > > speculative AT instruction with the proposal below. > > > > > > > > Thanks > > > > Raghu > > > > > > > > On 4/27/20 10:08 AM, Manish Badarkhe wrote: > > > > > Hi All, > > > > > > > > > > Just update/correct details. > > > > > > > > > > Thanks > > > > > Manish Badarkhe > > > > > > > > > > On 27/04/2020, 22:13, "TF-A on behalf of Manish Badarkhe > via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf- > a(a)lists.trustedfirmware.org> wrote: > > > > > > > > > > Hi Raghu > > > > > > > > > > Please ignore my answer on question 2. > > > > > > > > > > With internal discussion came to below conclusion: > > > > > 1. This workaround is very specific during context > switching. > > > > > 2 . If you check in context save routine > (el1_sysregs_context_save or el2_sysregs_context_save), > > > > > As per proposed solution, First step performed is to > disable page table walk and we don’t have > > > > > any AT instruction execution in context save routine. > > > > > This ensures that there will be no possibility of > speculative AT instruction execution without TCR update. > > > > > 3. If you check in context restore routine > (el1_sysregs_context_restore or el2_sysregs_context_restore), > > > > > As per proposed solution, first step performed is to > disable page table walk and we don’t have any > > > > > AT instruction execution in context restore routine. > > > > > This ensures that there will be no possibility of > speculative AT instruction execution without TCR update. > > > > > > > > > > Hence proposed solution will work as it is ensuring no > caching of translations in TLB while speculative AT instruction execution. > > > > > > > > > > Thanks > > > > > Manish Badarkhe > > > > > > > > > > On 27/04/2020, 13:38, "TF-A on behalf of Manish Badarkhe > via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf- > a(a)lists.trustedfirmware.org> wrote: > > > > > > > > > > Hi Raghu > > > > > > > > > > Please see my answers inline > > > > > > > > > > On 25/04/2020, 06:38, "TF-A on behalf of Raghu K via TF- > A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf- > a(a)lists.trustedfirmware.org> wrote: > > > > > > > > > > Hi Manish, > > > > > > > > > > Before I agree or disagree with the suggested fix, the > following would > > > > > be interesting to know/discuss. Please feel free to > correct me if i've > > > > > misunderstood something. > > > > > > > > > > 1) Are "speculative" AT instructions subject to TCR_ELx > control bits for > > > > > all the listed CPU's? I imagine the answer is yes but > would be good to > > > > > get confirmation. I could not find any evidence in the > instruction > > > > > description or psuedocode in the ARMv8 ARM. It is > possible to play many > > > > > tricks on speculative execution of instructions such as > skipping checks > > > > > and doing them only when the CPU knows the > instruction will be > > > > > committed. If this is the case, changing TCR_ELx bits > may not work. The > > > > > errata document is vague about how to fix it. > > > > > > > > > > The speculative AT instruction may behave as you > mentioned. We need more > > > > > opinion on this. > > > > > Proposed fix I mentioned by referring linux workaround > for the same errata. > > > > > Linux workaround is available in mainline kernel as > below: > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… > v5.7-rc3&id=bd227553ad5077f21ddb382dcd910ba46181805a > > > > > > > > > > 2) Assuming the answer to question 1 is yes, your > proposal may not work > > > > > as is. In the worst case, as soon as you enter EL3, the > very first thing > > > > > that may happen, before you ever operate/write to > TCR_ELx, is a > > > > > speculative AT instruction that caches a bad translation > in the TLB's. > > > > > The same thing can happen on the exit path. As soon as > you restore the > > > > > TCR_ELx register, the first thing that can happen is a > speculative AT > > > > > that caches a bad translation. However, the el3_exit > path does have DSB > > > > > before ERET, so we will not speculate to an AT > instruction if there are > > > > > no branches between the instruction that sets TCR_ELx > and the ERET. > > > > > Somewhere in between, it looks like we will need a > TLBI NSH to be > > > > > certain there are no bad translation cached. This > obviously has a > > > > > potential performance cost on the lower EL's. Every > entry into EL3 > > > > > flushes the TLB for lower EL's. > > > > > > > > > > Yes, this seems to be valid case during entry and exit path. > > > > > I am not quite sure in that case where we need to avoid > PTW. > > > > > Also "TLBI NSH" works but it may cause performance > issue. > > > > > Need some more opinion/thoughts on this. > > > > > > > > > > Just thinking, can sequence mentioned for context save > does not ensure that > > > > > PTW is disabled? > > > > > Something as below as last step in ELx(1/2) context save > (elaborated more): > > > > > > ·Save TCR register with PTW enable (EPD=0). (Just to > enable PTW during > > > > > > restore context). Do not operate TCR_EL1x register > here just save its value to restore. > > > > > > This ensures that during entry in EL3 there will be no > chance of PTW > > > > > >. while executing AT instruction. > > > > > > > > > > Thanks > > > > > > > > > > Raghu > > > > > > > > > > Thanks > > > > > Manish Badarkhe > > > > > > > > > > On 4/24/20 2:56 AM, Manish Badarkhe via TF-A wrote: > > > > > > > > > > > > Hi All > > > > > > > > > > > > We are trying to implement errata which is applicable > for below CPUs: > > > > > > > > > > > > <CPUs> : <Errata No.> > > > > > > > > > > > > Cortex-A53: 1530924 > > > > > > > > > > > > Cortex-A76: 1165522 > > > > > > Cortex-A72: 1319367 > > > > > > Cortex-A57: 1319537 > > > > > > Cortex-A55: 1530923 > > > > > > > > > > > > *Errata Description:* > > > > > > > > > > > > A speculative Address Translation (AT) instruction > translates using > > > > > > registers that are associated with an out-of-context > translation > > > > > > regime and caches the resulting translation in the TLB. > A subsequent > > > > > > translation request that is generated when the out- > of-context > > > > > > translation regime is current uses the previous cached > TLB entry > > > > > > producing an incorrect virtual to physical mapping. > > > > > > > > > > > > *Probable solution is to implement below fix in > context.S file:* > > > > > > > > > > > > *During ELx (1 or 2) context save:* > > > > > > > > > > > > ·Operate TCR_ELx(1/2) to disable page table walk by > operating EPD bits > > > > > > > > > > > > oThis will avoid any page table walk for S-EL1 or S-EL2. > This will > > > > > > help in avoiding caching of translations in TLB > > > > > > > > > > > > for S-EL1/S-EL2 in EL3. > > > > > > > > > > > > ·Save all system registers (which is already available) > except TCR > > > > > > > > > > > > ·Clear EPD bits of TCR and then save. (Just to enable > PTW during > > > > > > restore context). > > > > > > > > > > > > *During ELx (1 or 2) context restore:* > > > > > > > > > > > > * Operate TCR_ELx(1/2) to disable page table walk > by operating EPD bits > > > > > > * Restore all system registers (which are saved > during context save) > > > > > > except TCR register. > > > > > > * Restore TCR_ELx(1/2) register (which enable back > PTW). > > > > > > > > > > > > With above we ensured that there will be no page > table walk for S-EL1 > > > > > > and S-EL2 in EL3. > > > > > > > > > > > > is this proper other way to fix this problem? Need > some suggestion/use > > > > > > cases where and all we need this workaround in TF-A > code. > > > > > > > > > > > > Thanks > > > > > > > > > > > > Manish Badarkhe > > > > > > > > > > > > IMPORTANT NOTICE: The contents of this email and > any attachments are > > > > > > confidential and may also be privileged. If you are not > the intended > > > > > > recipient, please notify the sender immediately and > do not disclose > > > > > > the contents to any other person, use it for any > purpose, or store or > > > > > > copy the information in any medium. Thank you. > > > > > > > > > > > > > > > > -- > > > > > TF-A mailing list > > > > > TF-A(a)lists.trustedfirmware.org > > > > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a > > > > > > > > > > IMPORTANT NOTICE: The contents of this email and any > attachments are confidential and may also be privileged. If you are not the > intended recipient, please notify the sender immediately and do not disclose > the contents to any other person, use it for any purpose, or store or copy the > information in any medium. Thank you. > > > > > -- > > > > > TF-A mailing list > > > > > TF-A(a)lists.trustedfirmware.org > > > > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a > > > > > > > > > > IMPORTANT NOTICE: The contents of this email and any > attachments are confidential and may also be privileged. If you are not the > intended recipient, please notify the sender immediately and do not disclose > the contents to any other person, use it for any purpose, or store or copy the > information in any medium. Thank you. > > > > > -- > > > > > TF-A mailing list > > > > > TF-A(a)lists.trustedfirmware.org > > > > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a > > > > > > > > > > IMPORTANT NOTICE: The contents of this email and any > attachments are confidential and may also be privileged. If you are not the > intended recipient, please notify the sender immediately and do not disclose > the contents to any other person, use it for any purpose, or store or copy the > information in any medium. Thank you. > > > > > > > > > > > > IMPORTANT NOTICE: The contents of this email and any > attachments are confidential and may also be privileged. If you are not the > intended recipient, please notify the sender immediately and do not disclose > the contents to any other person, use it for any purpose, or store or copy the > information in any medium. Thank you. > > > > > > > > > > IMPORTANT NOTICE: The contents of this email and any attachments > are confidential and may also be privileged. If you are not the intended > recipient, please notify the sender immediately and do not disclose the > contents to any other person, use it for any purpose, or store or copy the > information in any medium. Thank you. > > > > > > -- > > TF-A mailing list > > TF-A(a)lists.trustedfirmware.org > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a > > > -- > TF-A mailing list > TF-A(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-a

5 years, 5 months

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Re: [TF-A] Project Maintenance Proposal for tf.org Projects

by Sandrine Bailleux

Hi all, I've received very little feedback on version 2 of the proposal, which hints that we are reaching an agreement. Thus, I plan to finalize the proposal this week. This can then become part of our development flow for all trustedfirmware.org projects. Thanks again for all the inputs! Regards, Sandrine Bailleux

5 years, 6 months

1
0
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