- Hafnium - lists.trustedfirmware.org

by Don Harbin

Hi All, To all TF maillists in case all aren't yet aware. We've created a Discord Server for real time chats/sharing. This solution comes at no cost to the project, is set up with channels for each project, includes a #general channel, and supports direct 1-1 chats between members, all with the goal of improving collaboration between trustedfirmware.org developers. I've attached a recent screenshot from the #general channel as a sample of the interface and usages. We encourage all to join! :) Instructions for joining can be found on the TF.org FAQ page <https://www.trustedfirmware.org/faq/>. See you all there and please don't hesitate to reach out if you have any questions! Don Harbin TrustedFirmware Community Manager don.harbin(a)linaro.org

2 years, 10 months

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Hafnium documentation moved to readthedocs

by Olivier Deprez

Hi, This is to inform that the Hafnium documentation is being migrated to its own ReadTheDocs project (from TF-A RTD project): https://hafnium.readthedocs.io This primarily concerns the SPM design doc and threat model. Hafnium documentation changes should target hafnium tree moving forward: https://git.trustedfirmware.org/hafnium/hafnium.git/tree/docs The remaining work over the coming days is: -creating a docs watcher automatically triggering RTD builds. -polishing few leftovers originating from TF-A in migrated documents. -cleanly removing the now duplicated docs from TF-A tree. If any question feel free to reach to the team. Regards, Olivier.

2 years, 12 months

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multiple SP secondary boot

by 梅建强(禹夜)

Hi, Madhu, Olivier, I am glad that I have the same understanding as both of you about description in FF-A 1.1 18.3.2.1.1. Other points to discuss: >For SPs beyond the first SP, it is up to the normal world driver to invoke FFA_RUN for each secondary vCPU. OK, I basically understand what you said. But I did not use this interface. I need to make it clear for my current implementation for booting secondary vCPUs on SPs beyond the first SP. I connect all vCPUs with the same index on all SP. If there is no vCPU for the current index, just skip to next vCPU with the same index on next SP. So for each index, we can build a vCPU boot list. Later when the nwd boots, upon invocation of PSCI_CPU_ON, each secondary vCPU for the first SP get initialized. Then Hafnium starts the next secondary vCPU on SP beyond the first SP according to the boot list. At present, we have implemented it and tested it without problems. Is this a violation of the FF-A spe, or is there any other problem? >Note I don't believe the current optee linux driver supports the above. >In which case the scenario you describe (multiple optee instances) might not work out of the box. Agree. >Also note there must be other issues like how to handle the secure storage when multiple optee instances exists. Could you describe it in more detail? Thanks for your supports. Regards, Yuye. ------------------------------------------------------------------ 发件人：Olivier Deprez <Olivier.Deprez(a)arm.com> 发送时间：2023年7月17日(星期一) 22:29 收件人：Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com>; 梅建强(禹夜) <meijianqiang.mjq(a)alibaba-inc.com> 抄　送：hafnium <hafnium(a)lists.trustedfirmware.org>; 高海源(码源) <haiyuan.ghy(a)alibaba-inc.com>; 王一蒙(北见) <wym389994(a)alibaba-inc.com>; 黄明(连一) <hm281385(a)alibaba-inc.com> 主　题：Re: [Hafnium] multiple SP secondary boot Hi, I'm adding to Madhu's reply: At TF-A /secure boot time, before nwd is initialized, the first vCPU for each SP is resumed in sequence by the SPMC. It gives the opportunity for each SP to define a secondary boot address for later resuming of secondary vCPUs. Later when the nwd boots, upon invocation of PSCI_CPU_ON, each secondary vCPU for the first SP get initialized. For SPs beyond the first SP, it is up to the normal world driver to invoke FFA_RUN for each secondary vCPU. Note I don't believe the current optee linux driver supports the above. In which case the scenario you describe (multiple optee instances) might not work out of the box. Also note there must be other issues like how to handle the secure storage when multiple optee instances exists. This might work though if you decide to strip down optee instances to a very minimal set of features, that do not use the same resources. We might help further if you provide a bit more details about the intended setup/scenario. Regards, Olivier. From: Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com> Sent: 17 July 2023 16:19 To: 梅建强(禹夜) <meijianqiang.mjq(a)alibaba-inc.com>; Olivier Deprez <Olivier.Deprez(a)arm.com> Cc: hafnium <hafnium(a)lists.trustedfirmware.org>; 高海源(码源) <haiyuan.ghy(a)alibaba-inc.com>; 王一蒙(北见) <wym389994(a)alibaba-inc.com>; 黄明(连一) <hm281385(a)alibaba-inc.com> Subject: RE: [Hafnium] multiple SP secondary boot Hi Yuye, I think the following sentence in the spec is slightly confusing. " For each SP and the SPMC, the Framework assumes that the same entry point address is used for initializing any execution context during a secondary cold boot." I believe what it meant is that the entry point address for any secondary execution context of a particular SP is the same. Note that the entry point of secondary execution contexts belonging to another SP is different than the one previously registered. I can confirm that Hafnium adheres to the above statement. Please note that the cold boot flow is different for secondary cores compared to primary core. On the primary core, SPMC initializes the execution contexts of all SPs( refer to [1]). However, execution contexts of non-primary SP on secondary cores need CPU cycles to be allocated by the NWd scheduler through the FFA_RUN interface(refer to [2]). Hopefully, I was able to answer your questions. [1] https://git.trustedfirmware.org/hafnium/hafnium.git/tree/src/arch/aarch64/p… <https://git.trustedfirmware.org/hafnium/hafnium.git/tree/src/arch/aarch64/p… > [2] https://git.trustedfirmware.org/hafnium/hafnium.git/tree/src/api.c#n1047 <https://git.trustedfirmware.org/hafnium/hafnium.git/tree/src/api.c#n1047 > Thanks, Madhu -----Original Message----- From: 梅建强(禹夜) via Hafnium <hafnium(a)lists.trustedfirmware.org> Sent: Saturday, July 15, 2023 4:54 AM To: Olivier Deprez <Olivier.Deprez(a)arm.com> Cc: hafnium <hafnium(a)lists.trustedfirmware.org>; 高海源(码源) <haiyuan.ghy(a)alibaba-inc.com>; 王一蒙(北见) <wym389994(a)alibaba-inc.com>; 黄明(连一) <hm281385(a)alibaba-inc.com> Subject: [Hafnium] multiple SP secondary boot Hi, Olivier, There's a problem I'd like to discuss with you. In the FF-A 1.1 18.3.2.1.1 section, it is described as follows: For each SP and the SPMC, the Framework assumes that the same entry point address is used for initializing any execution context during a secondary cold boot. This does not seem to make sense for entry point addresses of multiple SP. In addition, I do not see support for the secondary boot of the multiple SP in the current implementation of Hafnium. If I have multiple optee instances of MP type, how should I design the cold secondary boot flow for multiple SP? My idea is to build a vCPU list with the same index between VMs, just like primary boot flow, as shown in the code below: void vcpu_update_boot(struct vcpu *vcpu) { struct vcpu *current = NULL; struct vcpu *previous = NULL; if (boot_vcpu == NULL) { boot_vcpu = vcpu; return; } current = boot_vcpu; while (current != NULL && current->vm->boot_order <= vcpu->vm->boot_order) { previous = current; current = current->next_boot; } if (previous != NULL) { previous->next_boot = vcpu; } else { boot_vcpu = vcpu; } vcpu->next_boot = current; } Anyone else have some good suggestions? Thanks for the support. Regards, Yuye. -- Hafnium mailing list -- hafnium(a)lists.trustedfirmware.org To unsubscribe send an email to hafnium-leave(a)lists.trustedfirmware.org

2 years, 12 months

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Question about SMMU S-2 translation

by Chenxu Wang

Hi all, I'd like to ask some questions about how the SMMU S-2 translation works. My questions are as follows: 1. When SMMU performs Stage-2 translation (I mean, fetches the translation table and walks it), is it constrained by GPC on CPU MMU, or GPC on SMMU, or both? For example, assume I configure the PAS of the non-secure SMMU S-2 translation table as "secure/realm/root PAS" in CPU MMU GPC, but "non-secure PAS" in SMMU (e.g., the SMMU for TestEngine on FVP) GPC, will the SMMU successfully perform S-2 translation? Or in another example, assume I configure the PAS of the non-secure SMMU S-2 translation table as "non-secure PAS" in CPU MMU GPC, but "secure/realm/root PAS" in SMMU (e.g., the SMMU for TestEngine on FVP) GPC, will the SMMU successfully perform S-2 translation? 2. Currently I use Hafnium to configure the SMMU. Due to memory limitation, I want to place the SMMU Stage-2 table in DRAM2 (starting from 0x8_8000_0000, but this region is not mapped in Hafnium). Since I think the SMMU S-2 translation is influenced by EL2 S-1 translation (really?), can I turn off the EL2 S-1 translation in Hafnium to avoid this problem? If yes, how to do it? Sincerely, WANG Chenxu

3 years

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multiple SP secondary boot

by 梅建强(禹夜)

Hi, Olivier, There's a problem I'd like to discuss with you. In the FF-A 1.1 18.3.2.1.1 section, it is described as follows: For each SP and the SPMC, the Framework assumes that the same entry point address is used for initializing any execution context during a secondary cold boot. This does not seem to make sense for entry point addresses of multiple SP. In addition, I do not see support for the secondary boot of the multiple SP in the current implementation of Hafnium. If I have multiple optee instances of MP type, how should I design the cold secondary boot flow for multiple SP? My idea is to build a vCPU list with the same index between VMs, just like primary boot flow, as shown in the code below: void vcpu_update_boot(struct vcpu *vcpu) { struct vcpu *current = NULL; struct vcpu *previous = NULL; if (boot_vcpu == NULL) { boot_vcpu = vcpu; return; } current = boot_vcpu; while (current != NULL && current->vm->boot_order <= vcpu->vm->boot_order) { previous = current; current = current->next_boot; } if (previous != NULL) { previous->next_boot = vcpu; } else { boot_vcpu = vcpu; } vcpu->next_boot = current; } Anyone else have some good suggestions? Thanks for the support. Regards, Yuye.

3 years

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Re: optee_benchmark found optee_os function vm_set_ctx() spent much time

by jens.wiklander＠linaro.org

The content of this message was lost. It was probably cross-posted to multiple lists and previously handled on another list.

3 years

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optee_benchmark found optee_os function vm_set_ctx() spent much time

by 高海源(码源)

Hi, Jens, Olivier: I'm a colleague of Yuye, and we are doing optee benchmark and performance optimization. We are using optee_os/optee_client/optee_examples/optee_benchmark version 3.20.0 We think the host API TEEC_InvokeCommand() is sensitive of delay, namely TEE framework like OpenEnclave called ECALL. So we remove all prints in hello_world_ta.c 's TA_InvokeCommandEntryPoint(), host test TEEC_InvokeCommand() 10k times to calculate average time cost. We tested on an ArmV9 data-center server, and we got average time is about 20 us. After using optee_benchmark tool, we found optee_os function user_ta_enter() took most of time. Specially, user_ta_enter() calls ts_push_current_session() and ts_pop_current_session(), then calls vm_set_ctx() twice, which spend 7 us and 2 us respectively, mostly of 20 us delay. I added logs to print some pointers, following is the log in update_current_ctx() I found that many InvokeCommand repeat following pattern E/TC:??? 000 user_ta_enter:155 ====== session 0x8940b5d80 func 2 cmd 4, call ts_push_current_session E/TC:??? 000 update_current_ctx:29 session 0x8940b5d80 tsd 0x89008dd38 tsd->ctx 0x0 ctx 0x8940b5d28 E/TC:??? 000 user_ta_enter:199 ====== session 0x8940b5d80 func 2 cmd 4, call ts_pop_current_session E/TC:??? 000 update_current_ctx:29 session 0x0 tsd 0x89008dd38 tsd->ctx 0x8940b5d28 ctx 0x0 I noticed many InvokeCommand use the same ctx pointer like 0x8940b5d28 My question is: Can many InvokeCommand avoid setting tsd->ctx to Non-NULL ctx, then NULL ctx, to remove the vm_set_ctx() cost of time? Is there any optimization method, likely many InvokeCommand in the same session reuse the same Non-NULL ctx, to reduce average delay of ECALLs? Thanks. Best wishes. ------------------------------------------------------------------ 发件人：Olivier Deprez<Olivier.Deprez(a)arm.com> 日　期：2023年05月30日 21:07:20 收件人：Jens Wiklander<jens.wiklander(a)linaro.org>; 梅建强(禹夜)<meijianqiang.mjq(a)alibaba-inc.com> 抄　送：op-tee<op-tee(a)lists.trustedfirmware.org>; hafnium<hafnium(a)lists.trustedfirmware.org>; 黄明<hm281385(a)alibaba-inc.com> 主　题：Re: optee_benchmark pmccfiltr_el0 Hi Yuye, In general the consensus is that PMU cycle and event counting in EL3 & secure world has to be disabled. I gather this is to avoid probing crypto algorithms timings, or leverage cache-based timing side channels (e.g. spectre). See Arm ARM D11.5.3 Prohibiting event and cycle counting Cycle and event counting is disabled by: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/include/ar… <https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/include/ar… > See also https://trustedfirmware-a.readthedocs.io/en/latest/process/security-hardeni… <https://trustedfirmware-a.readthedocs.io/en/latest/process/security-hardeni… > Note there are various knobs depending on implemented architecture extensions FEAT_PMUv3 / FEAT_PMUv3pX / FEAT_Debugv8p2 You could try to permit cycle counting in the secure world for the sake of a one shot experiment, but note that this has never been tried, and this should probably not be productized as things stand. Regards, Olivier. From: 梅建强(禹夜) <meijianqiang.mjq(a)alibaba-inc.com> Sent: 30 May 2023 10:38 To: Jens Wiklander <jens.wiklander(a)linaro.org>; Olivier Deprez <Olivier.Deprez(a)arm.com> Cc: op-tee <op-tee(a)lists.trustedfirmware.org>; hafnium <hafnium(a)lists.trustedfirmware.org>; 黄明(连一) <hm281385(a)alibaba-inc.com> Subject: optee_benchmark pmccfiltr_el0 Hi, It is confirmed that the problem is related to the pmu register configuration and that pmccntr_el0 can be read at any exception level. Regards, Yuye. ------------------------------------------------------------------ 发件人：梅建强(禹夜) <meijianqiang.mjq(a)alibaba-inc.com> 发送时间：2023年5月26日(星期五) 16:59 收件人：Jens Wiklander <jens.wiklander(a)linaro.org>; Olivier Deprez <olivier.deprez(a)arm.com> 抄　送：op-tee <op-tee(a)lists.trustedfirmware.org>; hafnium <hafnium(a)lists.trustedfirmware.org>; 黄明(连一) <hm281385(a)alibaba-inc.com> 主　题：optee_benchmark pmccfiltr_el0 Hi, Jens, Olivier, In case of that optee runs at sel1 and hafnium runs at sel2, we want to test benchmark by executing the following command at optee_benchmark path: ./out/benchmark ../optee_examples/out/ca/optee_example_hello_world After entering into the benchmark pta, the bm_timestamp function attempts to read the pmccfiltr_el0 register. In cold boot, the following code will be executed during hafnium initialization: vm->arch.trapped_features |= HF_FEATURE_PERFMON; This will prevent the secondary vm from accessing the performance counter registers. We remove the code, the bm_timestamp function can read pmccfiltr_el0 without trapping into hafnium. But the value of pmccfiltr_el0 remains unchanged and cannot be counted. We tried to read the register in hafnium and found that there was no change either. In contrast, in the normal world, pmccfiltr_el0 counts normally. Is it related to the pmu register configuration or does sel1 not support the pmccfiltr_el0 count at present? Thanks for the support. Regards, Yuye.

3 years

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Hafnium with QEMU and OP-TEE

by Jens Wiklander

Hi, I'm testing with Hafnium as SPMC at S-EL2 and OP-TEE as an SP at S-EL1 on QEMU v7.0.0. I've run into a few problems and fixed most of them. I believe the setup is similar to what Shiju is using in this mail thread https://lists.trustedfirmware.org/archives/list/hafnium@lists.trustedfirmwa… My setup can be duplicated with: repo init -u https://github.com/jenswi-linaro/manifest.git -m qemu_v8.xml \ -b qemu_sel2 repo sync -j8 (cd hafnium && git submodule init && git submodule update) cd build make -j8 toolchains make -j8 all make run-only With this xtest -x 1034 passes, xtest 1034 often causes ERROR: Data abort: pc=0xe1198b8, esr=0x96000006, ec=0x25, far=0x9c Panic: EL2 exception Xtest runs dreadfully slow, I haven't investigated why yet, but at least it works. This is based on patches provided by Olivier at: [1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/16412/2 [2] https://review.trustedfirmware.org/c/hafnium/hafnium/+/16323/7 I've also encountered the problem cache maintenance problem Shiju described in the mail thread above: NOTICE: Trapped access to system register write: op0=1, op1=0, crn=7, crm=14, op2=2, rt=11. It can be worked around by compiling OP-TEE with CFG_CORE_WORKAROUND_NSITR_CACHE_PRIME=n. I'm pretty sure we do dcache clean+inv elsewhere so I'm surprised it fails here. Is Hafnium expected to block dcache clean+inv? For Hafnium I've added two patches on top of [2], available at https://github.com/jenswi-linaro/hafnium/tree/qemu_sel2: - 79b4d2cbe06e SPMC: add missing ME initialization for secondary cores - 659c79d5eacf feat(mm): fix FEAT_LPA workaround For TF-A I've added a few patches on top of [1], available at https://github.com/jenswi-linaro/arm-trusted-firmware/tree/qemu_sel2: - a040396cae9e feat(qemu): add tos-fw-config for sel2 spmc - 4f7d91723485 fix(qemu): change TOS_FW_CONFIG_NAME value - fbfc9a222c7f spmd_smc_handler() add s/ns state to SMC traces - ca65081b9cdc feat(sptool): add dependency to SP image - b1e1b46a0680 fix(qemu): restore code to added needed psci nodes For OP-TEE I've also added a few patches, available at https://github.com/jenswi-linaro/optee_os/tree/qemu_sel2: - 1057def23777 plat-vexpress: sel2 spmc: update for hafnium - f18a54ed3524 core: ffa: use hvc instead of smc with S-EL2 - d18bbc92f7c1 core: mobj_ffa_add_pages_at() trust addresses from SPMC There's also one patch for QEMU on top of v7.0.0, available at: https://github.com/jenswi-linaro/qemu/tree/qemu_sel2 - 0c1e39672dcb Read PS bits from VTCR_EL2 The QEMU problem is fixed in v.7.1.0, but I can't get that version of QEMU to work with TF-A. I guess it's because of yet another new CPU feature since I'm running with "-cpu max". I'll try to upstream the Hafnium and TF-A patches that make sense on their own. What's the plan with the interrupt controller? How will OP-TEE be able to handle secure interrupts? The hafnium git pulls in a few git submodules and even the source code for a Linux kernel. I guess this is useful in your internal CI setup, but when used isolated as in my setup it makes no sense at all. It would also be nice to be able to build with an external toolchain. I hope this is a temporary situation, I don't see why Hafnium should be pickier about toolchain than for instance TF-A. Speaking of building, I haven't been able to figure out how to build only for the QEMU variant I need so right now I'm building for everything and that takes a bit longer than necessary. I'm going to maintain the setup above as long as it's relevant to me. I may add more patches on the branches or even rebase as needed. So if anyone is using this, keep in mind that my branches may change without warning. Thanks, Jens

3 years, 1 month

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optee_benchmark pmccfiltr_el0

by 梅建强(禹夜)

Hi, Olivier, That makes it clearer to me. Thanks a lot. Regards, Yuye. ------------------------------------------------------------------ 发件人：Olivier Deprez <Olivier.Deprez(a)arm.com> 发送时间：2023年5月30日(星期二) 21:07 收件人：Jens Wiklander <jens.wiklander(a)linaro.org>; 梅建强(禹夜) <meijianqiang.mjq(a)alibaba-inc.com> 抄　送：op-tee <op-tee(a)lists.trustedfirmware.org>; hafnium <hafnium(a)lists.trustedfirmware.org>; 黄明(连一) <hm281385(a)alibaba-inc.com> 主　题：Re: optee_benchmark pmccfiltr_el0 Hi Yuye, In general the consensus is that PMU cycle and event counting in EL3 & secure world has to be disabled. I gather this is to avoid probing crypto algorithms timings, or leverage cache-based timing side channels (e.g. spectre). See Arm ARM D11.5.3 Prohibiting event and cycle counting Cycle and event counting is disabled by: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/include/ar… <https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/include/ar… > See also https://trustedfirmware-a.readthedocs.io/en/latest/process/security-hardeni… <https://trustedfirmware-a.readthedocs.io/en/latest/process/security-hardeni… > Note there are various knobs depending on implemented architecture extensions FEAT_PMUv3 / FEAT_PMUv3pX / FEAT_Debugv8p2 You could try to permit cycle counting in the secure world for the sake of a one shot experiment, but note that this has never been tried, and this should probably not be productized as things stand. Regards, Olivier. From: 梅建强(禹夜) <meijianqiang.mjq(a)alibaba-inc.com> Sent: 30 May 2023 10:38 To: Jens Wiklander <jens.wiklander(a)linaro.org>; Olivier Deprez <Olivier.Deprez(a)arm.com> Cc: op-tee <op-tee(a)lists.trustedfirmware.org>; hafnium <hafnium(a)lists.trustedfirmware.org>; 黄明(连一) <hm281385(a)alibaba-inc.com> Subject: optee_benchmark pmccfiltr_el0 Hi, It is confirmed that the problem is related to the pmu register configuration and that pmccntr_el0 can be read at any exception level. Regards, Yuye. ------------------------------------------------------------------ 发件人：梅建强(禹夜) <meijianqiang.mjq(a)alibaba-inc.com> 发送时间：2023年5月26日(星期五) 16:59 收件人：Jens Wiklander <jens.wiklander(a)linaro.org>; Olivier Deprez <olivier.deprez(a)arm.com> 抄　送：op-tee <op-tee(a)lists.trustedfirmware.org>; hafnium <hafnium(a)lists.trustedfirmware.org>; 黄明(连一) <hm281385(a)alibaba-inc.com> 主　题：optee_benchmark pmccfiltr_el0 Hi, Jens, Olivier, In case of that optee runs at sel1 and hafnium runs at sel2, we want to test benchmark by executing the following command at optee_benchmark path: ./out/benchmark ../optee_examples/out/ca/optee_example_hello_world After entering into the benchmark pta, the bm_timestamp function attempts to read the pmccfiltr_el0 register. In cold boot, the following code will be executed during hafnium initialization: vm->arch.trapped_features |= HF_FEATURE_PERFMON; This will prevent the secondary vm from accessing the performance counter registers. We remove the code, the bm_timestamp function can read pmccfiltr_el0 without trapping into hafnium. But the value of pmccfiltr_el0 remains unchanged and cannot be counted. We tried to read the register in hafnium and found that there was no change either. In contrast, in the normal world, pmccfiltr_el0 counts normally. Is it related to the pmu register configuration or does sel1 not support the pmccfiltr_el0 count at present? Thanks for the support. Regards, Yuye.

3 years, 1 month

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optee_benchmark pmccfiltr_el0

by 梅建强(禹夜)

Hi, It is confirmed that the problem is related to the pmu register configuration and that pmccntr_el0 can be read at any exception level. Regards, Yuye. ------------------------------------------------------------------ 发件人：梅建强(禹夜) <meijianqiang.mjq(a)alibaba-inc.com> 发送时间：2023年5月26日(星期五) 16:59 收件人：Jens Wiklander <jens.wiklander(a)linaro.org>; Olivier Deprez <olivier.deprez(a)arm.com> 抄　送：op-tee <op-tee(a)lists.trustedfirmware.org>; hafnium <hafnium(a)lists.trustedfirmware.org>; 黄明(连一) <hm281385(a)alibaba-inc.com> 主　题：optee_benchmark pmccfiltr_el0 Hi, Jens, Olivier, In case of that optee runs at sel1 and hafnium runs at sel2, we want to test benchmark by executing the following command at optee_benchmark path: ./out/benchmark ../optee_examples/out/ca/optee_example_hello_world After entering into the benchmark pta, the bm_timestamp function attempts to read the pmccfiltr_el0 register. In cold boot, the following code will be executed during hafnium initialization: vm->arch.trapped_features |= HF_FEATURE_PERFMON; This will prevent the secondary vm from accessing the performance counter registers. We remove the code, the bm_timestamp function can read pmccfiltr_el0 without trapping into hafnium. But the value of pmccfiltr_el0 remains unchanged and cannot be counted. We tried to read the register in hafnium and found that there was no change either. In contrast, in the normal world, pmccfiltr_el0 counts normally. Is it related to the pmu register configuration or does sel1 not support the pmccfiltr_el0 count at present? Thanks for the support. Regards, Yuye.

3 years, 1 month

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Hafnium