Hi,
On Mon, May 27, 2024 at 03:24:01PM +0200, Jens Wiklander wrote:
On Mon, May 27, 2024 at 3:00 PM Jerome Forissier jerome.forissier@linaro.org wrote:
On 5/27/24 14:13, Jens Wiklander wrote:
Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and use an RPMB device via the RPMB subsystem instead of passing the RPMB frames via tee-supplicant in user space. A fallback mechanism is kept to route RPMB frames via tee-supplicant if the RPMB subsystem isn't available.
The OP-TEE RPC ABI is extended to support iterating over all RPMB devices until one is found with the expected RPMB key already programmed.
Signed-off-by: Jens Wiklander jens.wiklander@linaro.org Tested-by: Manuel Traut manut@mecka.net
Documentation/ABI/testing/sysfs-class-tee | 15 ++ MAINTAINERS | 1 + drivers/tee/optee/core.c | 96 +++++++++++- drivers/tee/optee/device.c | 7 + drivers/tee/optee/ffa_abi.c | 14 ++ drivers/tee/optee/optee_ffa.h | 2 + drivers/tee/optee/optee_private.h | 26 +++- drivers/tee/optee/optee_rpc_cmd.h | 35 +++++ drivers/tee/optee/optee_smc.h | 2 + drivers/tee/optee/rpc.c | 177 ++++++++++++++++++++++ drivers/tee/optee/smc_abi.c | 14 ++ 11 files changed, 387 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-class-tee
diff --git a/Documentation/ABI/testing/sysfs-class-tee b/Documentation/ABI/testing/sysfs-class-tee new file mode 100644 index 000000000000..c9144d16003e --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-tee @@ -0,0 +1,15 @@ +What: /sys/class/tee/tee{,priv}X/rpmb_routing_model
Wouldn't /sys/class/tee/teeX/rpmb_routing_model be good enough?
Doesn't the routing model concern tee-supplicant more than a TEE client? Then it might make more sense to have /sys/class/tee/teeprivX/rpmb_routing_model only. Keeping it for both devices representing the same internal struct optee makes it easier to find. Anyway, I don't mind removing one. Mikko, what do you prefer?
As simple as possible. A single sysfs file is enough. Even the existence of the sysfs file could be the needed indicator for userspace to queue tee-supplicant startup.
Outside of these patches, I think the optee RPC setup with fTPM TA is one area which currently requires tee-supplicant to be started. Detecting the existence of TPM before kernel drivers are loaded is possible via the exported EFI logs from firmware to kernel or ACPI TPM2 table entry, and detecting optee and thus starting tee-supplicant in userspace too.
In userspace and systemd it's just important to know that service need to wait for a TPM2 device to appear in early initrd and when can things be postponed to main rootfs and later stages. Kernel and udev will bring up the device then once discovered. Knowledge about the RPMB backend is important when something like TPM2 device depends on it.
Hope this helps,
-Mikko