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From:   Masahisa Kojima <masahisa.kojima@linaro.org>
To:     Ard Biesheuvel <ardb@kernel.org>,
        Jens Wiklander <jens.wiklander@linaro.org>,
        Sumit Garg <sumit.garg@linaro.org>,
        linux-kernel@vger.kernel.org, op-tee@lists.trustedfirmware.org
Cc:     Ilias Apalodimas <ilias.apalodimas@linaro.org>,
        Johan Hovold <johan+linaro@kernel.org>,
        Masahisa Kojima <masahisa.kojima@linaro.org>
Subject: [PATCH v4 0/3] introduce tee-based EFI Runtime Variable Service
Date:   Tue, 23 May 2023 18:06:03 +0900
Message-Id: <20230523090607.1433-1-masahisa.kojima@linaro.org>
MIME-Version: 1.0
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Precedence: bulk

This series introduces the tee based EFI Runtime Variable Service.

The eMMC device is typically owned by the non-secure world(linux in
this case). There is an existing solution utilizing eMMC RPMB partition
for EFI Variables, it is implemented by interacting with
OP-TEE, StandaloneMM(as EFI Variable Service Pseudo TA), eMMC driver
and tee-supplicant. The last piece is the tee-based variable access
driver to interact with OP-TEE and StandaloneMM.

Changelog:
v3 -> v4:
- replace the reference from EDK2 to PI Specification
- remove EDK2 source code reference comments
- prepare nonblocking variant of set_variable, it just returns
  EFI_UNSUPPORTED
- remove redundant buffer size check
- argument name change in mm_communicate
- function interface changes in setup_mm_hdr to remove (void **) cast

v2 -> v3:
- add CONFIG_EFI dependency to TEE_STMM_EFI
- add missing return code check for tee_client_invoke_func()
- directly call efivars_register/unregister from tee_stmm_efi.c

rfc v1 -> v2:
- split patch into three patches, one for drivers/tee,
  one for include/linux/efi.h, and one for the driver/firmware/efi/stmm
- context/session management into probe() and remove() same as other tee
client driver
- StMM variable driver is moved from driver/tee/optee to driver/firmware/efi
- use "tee" prefix instead of "optee" in driver/firmware/efi/stmm/tee_stmm_efi.c,
  this file does not contain op-tee specific code, abstracted by tee layer and
  StMM variable driver will work on other tee implementation.
- PTA_STMM_CMD_COMMUNICATE -> PTA_STMM_CMD_COMMUNICATE
- implement query_variable_store() but currently not used
- no use of TEEC_SUCCESS, it is defined in driver/tee/optee/optee_private.h.
  Other tee client drivers use 0 instead of using TEEC_SUCCESS
- remove TEEC_ERROR_EXCESS_DATA status, it is referred just to output
error message

Masahisa Kojima (3):
  efi: expose efivar generic ops register function
  efi: Add EFI_ACCESS_DENIED status code
  efi: Add tee-based EFI variable driver

 drivers/firmware/efi/Kconfig                 |  15 +
 drivers/firmware/efi/Makefile                |   1 +
 drivers/firmware/efi/efi.c                   |  12 +
 drivers/firmware/efi/stmm/mm_communication.h | 236 +++++++
 drivers/firmware/efi/stmm/tee_stmm_efi.c     | 637 +++++++++++++++++++
 include/linux/efi.h                          |   4 +
 6 files changed, 905 insertions(+)
 create mode 100644 drivers/firmware/efi/stmm/mm_communication.h
 create mode 100644 drivers/firmware/efi/stmm/tee_stmm_efi.c

-- 
2.30.2