Re: [PATCH v13 09/10] arm_ffa: efi: introduce FF-A MM communication

Simon Glass
2023-06-20T10:28:14Z

On Fri, 16 Jun 2023 at 16:28, Abdellatif El Khlifi
<abdellatif.elkhlifi@arm.com> wrote:
>
> Add MM communication support using FF-A transport
>
> This feature allows accessing MM partitions services through
> EFI MM communication protocol. MM partitions such as StandAlonneMM
> or smm-gateway secure partitions which reside in secure world.
>
> An MM shared buffer and a door bell event are used to exchange
> the data.
>
> The data is used by EFI services such as GetVariable()/SetVariable()
> and copied from the communication buffer to the MM shared buffer.
>
> The secure partition is notified about availability of data in the
> MM shared buffer by an FF-A message (door bell).
>
> On such event, MM SP can read the data and updates the MM shared
> buffer with the response data.
>
> The response data is copied back to the communication buffer and
> consumed by the EFI subsystem.
>
> MM communication protocol supports FF-A 64-bit direct messaging.
>
> Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
> Signed-off-by: Gowtham Suresh Kumar <gowtham.sureshkumar@arm.com>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> Cc: Jens Wiklander <jens.wiklander@linaro.org>
>
> ---
>
> Changelog:
> ===============
>
> v13:
>
> * remove FF-A and Optee ifdefs
>
> v12:
>
> * drop use of calloc when querying SPs
> * address nits
>
> v11:
>
> * rename select_ffa_mm_comms() to select_mm_comms()
> * improve the logic of MM transport selection in mm_communicate()
> * addressing nits
>
> v10:
>
> * use the FF-A driver Uclass operations
> * use uclass_first_device()
> * addressing nits
>
> v9: align how FF-A is used with FF-A discovery through DM
>
> v8:
>
> * isolate the compilation choices between FF-A and OP-TEE
> * update partition_info_get() second argument to be an SP count
> * pass NULL device pointer to the FF-A bus discovery and operations
>
> v7:
>
> * set the MM door bell event to use 64-bit direct messaging
> * issue a compile time error when one of these macros are not found :
> FFA_SHARED_MM_BUFFER_SIZE, FFA_SHARED_MM_BUFFER_OFFSET, FFA_SHARED_MM_BUFFER_ADDR
> * make mm_sp_svc_uuid static
> * replace EINVAL with ENOMEM in ffa_discover_mm_sp_id() when calloc() fails
> * improve use of unmap_sysmem() in ffa_mm_communicate()
>
> v6:
>
> * add FF-A runtime discovery at MM communication level
> * drop EFI runtime support for FF-A MM communication
> * revert the changes in include/mm_communication.h for
> efi_mm_communicate_header and smm_variable_access structures
>
> v4:
>
> * use the new FF-A driver interfaces
> * discover MM partitions at runtime
> * copy FF-A driver private data to EFI runtime section at
> ExitBootServices()
> * drop use of FFA_ERR_STAT_SUCCESS error code
> * replace EFI_BUFFER_TOO_SMALL with EFI_OUT_OF_RESOURCES
> in ffa_mm_communicate(). No need for efi_memcpy_runtime() anymore
> * revert the error log in mm_communicate() in case of failure
> * remove packed attribute from efi_mm_communicate_header and
> smm_variable_communicate_header
>
> v2:
>
> * set default values to 0 for FFA_SHARED_MM_BUFFER_SIZE, FFA_SHARED_MM_BUFFER_ADDR and MM_SP_UUID_DATA and add warnings
>
> v1:
>
> * introduce FF-A MM communication
>
> include/mm_communication.h | 13 ++
> lib/efi_loader/Kconfig | 16 +-
> lib/efi_loader/efi_variable_tee.c | 260 +++++++++++++++++++++++++++++-
> 3 files changed, 282 insertions(+), 7 deletions(-)

Reviewed-by: Simon Glass <sjg@chromium.org>