Re: [RFC PATCH v3 0/4] TEE driver for AMD APUs

[Thomas, Rijo-john]

Hi Jens,

Please let me know if there are any comments for this patch series. I
shall address them, if any, and post for next review.

Thanks,
Rijo

On 06/12/19 10:48 am, Rijo Thomas wrote:
> This patch series introduces Trusted Execution Environment (TEE) driver
> for AMD APU enabled systems. The TEE is a secure area of a processor which
> ensures that sensitive data is stored, processed and protected in an
> isolated and trusted environment. The AMD Secure Processor is a dedicated
> processor which provides TEE to enable HW platform security. It offers
> protection against software attacks generated in Rich Operating
> System (Rich OS) such as Linux running on x86. The AMD-TEE Trusted OS
> running on AMD Secure Processor allows loading and execution of security
> sensitive applications called Trusted Applications (TAs). An example of
> a TA would be a DRM (Digital Rights Management) TA written to enforce
> content protection.
> 
> Linux already provides a tee subsystem, which is described in [1]. The tee
> subsystem provides a generic TEE ioctl interface which can be used by user
> space to talk to a TEE driver. AMD-TEE driver registers with tee subsystem
> and implements tee function callbacks in an AMD platform specific manner.
> 
> The following TEE commands are recognized by AMD-TEE Trusted OS:
> 1. TEE_CMD_ID_LOAD_TA : Load Trusted Application (TA) binary into TEE
>    environment
> 2. TEE_CMD_ID_UNLOAD_TA : Unload TA binary from TEE environment
> 3. TEE_CMD_ID_OPEN_SESSION : Open session with loaded TA
> 4. TEE_CMD_ID_CLOSE_SESSION : Close session with loaded TA
> 5. TEE_CMD_ID_INVOKE_CMD : Invoke a command with loaded TA
> 6. TEE_CMD_ID_MAP_SHARED_MEM : Map shared memory
> 7. TEE_CMD_ID_UNMAP_SHARED_MEM : Unmap shared memory
> 
> Each command has its own payload format. The AMD-TEE driver creates a
> command buffer payload for submission to AMD-TEE Trusted OS.
> 
> This patch series has a dependency on another patch set titled - Add TEE
> interface support to AMD Secure Processor driver.
> Link: https://lkml.org/lkml/2019/12/4/42
> 
> v3:
> * Updated [1] with driver details
> 
> v2:
> * Added a helper API in AMD Secure Processor driver, which can be
>   called by AMD-TEE driver during module init to check if TEE is
>   present on the device
> * Added proper checks for parameter attribute variable
> * Used tee_shm_pool_alloc() to allocate struct tee_shm_pool data structure
> * Removed all references to tee_private.h header file in driver code,
>   except for the file drivers/tee/amdtee/core.c. The driver loads TA binary
>   by calling request_firmware(), which takes struct device* as one of its
>   arguments. The device 'dev' field is part of struct tee_device, defined
>   in tee_private.h
> 
> [1] https://www.kernel.org/doc/Documentation/tee.txt
> 
> Rijo Thomas (4):
>   tee: allow compilation of tee subsystem for AMD CPUs
>   tee: add AMD-TEE driver
>   tee: amdtee: check TEE status during driver initialization
>   Documentation: tee: add AMD-TEE driver details
> 
>  Documentation/tee.txt               |  81 ++++++
>  drivers/crypto/ccp/tee-dev.c        |  11 +
>  drivers/tee/Kconfig                 |   4 +-
>  drivers/tee/Makefile                |   1 +
>  drivers/tee/amdtee/Kconfig          |   8 +
>  drivers/tee/amdtee/Makefile         |   5 +
>  drivers/tee/amdtee/amdtee_if.h      | 183 +++++++++++++
>  drivers/tee/amdtee/amdtee_private.h | 159 +++++++++++
>  drivers/tee/amdtee/call.c           | 373 ++++++++++++++++++++++++++
>  drivers/tee/amdtee/core.c           | 516 ++++++++++++++++++++++++++++++++++++
>  drivers/tee/amdtee/shm_pool.c       |  93 +++++++
>  include/linux/psp-tee.h             |  18 ++
>  include/uapi/linux/tee.h            |   1 +
>  13 files changed, 1451 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/tee/amdtee/Kconfig
>  create mode 100644 drivers/tee/amdtee/Makefile
>  create mode 100644 drivers/tee/amdtee/amdtee_if.h
>  create mode 100644 drivers/tee/amdtee/amdtee_private.h
>  create mode 100644 drivers/tee/amdtee/call.c
>  create mode 100644 drivers/tee/amdtee/core.c
>  create mode 100644 drivers/tee/amdtee/shm_pool.c
> 
> --
> 1.9.1
>