Re: [PATCH v4 00/22] arm64: FF-A runtime transport for EFI variables

[Harsimran Singh Tungal <harsimransingh.tungal@arm.com>]

On 7/30/26 13:12, Ilias Apalodimas wrote:
> Hi Peter,
>
>>
>> Hi Ilias,
>>
>>> I'll be off next week so this is going to take some time for a wider review.
>>> Since this is quite a lot of code to review, I'd prefer being able to
>>> test all of the cases to make sure nothing breaks and add more
>>> selftests in the future. I don't have access to a Corstone-1000.  The
>>
>> You can get the Corstone-1K FVP here:
>> https://corstone1000.docs.arm.com/en/corstone1000-2026.05/index.html
>>
>
> Ok thanks. I'd still prefer to have this on QEMU since we can
> reproduce all the cases there (variables in RPMB as of today + the
> FF-A variant). Even if we do use the FVP, I'd like to have information
> of how to build & test this as part of the cover letter, since Tom
> includes that in pull requests.
>
> Cheers
> /Ilias

Hi Ilias,

The instructions to build the Corstone-1000 FVP can be found here:
https://corstone1000.docs.arm.com/en/corstone1000-2026.05/user-guide.html.

For the QEMU/RPMB/OP-TEE question: QEMU RPMB would cover the storage
backend, but the FF-A runtime transport also needs the secure world to
expose the MM variable service through an FF-A secure partition. OP-TEE
alone would exercise the existing CONFIG_EFI_MM_COMM_TEE transport, not
the FF-A runtime transport, unless OP-TEE/SPMC is hosting an FF-A SP
that implements the same MM variable communication protocol.

For Corstone-1000 we are already using the Trusted Services SMM Gateway
SP. That SP implements the MM variable service and exposes the MM
Communicate endpoint over FF-A direct messages, which is the path used
by this series.

I agree that QEMU would be better for wider review and CI. I will have
to investigate the QEMU setup using the same SMM Gateway SP along with
OP-TEE/SPMC and RPMB, so we can reproduce the FF-A runtime variable path
without access to Corstone-1000.

Do you suggest that I investigate this QEMU setup for the
next revision?

The setup I am currently testing is Corstone-1000 FVP with the MM
variable service exposed through FF-A. The FF-A runtime path is tested
in two phases as follows:

The first phase (setup phase) creates the non-volatile runtime variable
before reset. On U-Boot prompt:

corstone1000# setenv efi_selftest 'variables at runtime setup'
corstone1000# bootefi selftest


Then reset the Corstone-1000 FVP and run the second phase.
The second phase verifies that the variable is available after reset,
then exercises runtime get/set/append/delete paths.
On U-Boot prompt after reset, execute the following commands:

corstone1000# setenv efi_selftest 'variables at runtime verify'
corstone1000# bootefi selftest

The testing steps are documented in the bootefi documentation commit:
doc: bootefi: note two-phase runtime variables selftest

For v5, I can add these tested steps to the cover letter.

Thanks
Harsimran Singh Tungal

>>> latest version of QEMU do support emulating an RPMB device. Would the
>>> changes above work with with an SP, QEMU RPMB and OP-TEE?
>>>
>>> Thanks
>>> /Ilias
>>>
>>> On Wed, 29 Jul 2026 at 11:51, Harsimran Singh Tungal
>>> <harsimransingh.tungal@arm.com> wrote:
>>>>
>>>> Hi all,
>>>>
>>>> This series adds FF-A runtime transport support so EFI variable runtime
>>>> services can communicate with the secure world after ExitBootServices().
>>>> It also extends tests, documentation, and Corstone-1000 configuration to
>>>> validate the runtime path and keep boot-time behavior aligned with the
>>>> runtime flow.
>>>>
>>>> Changes in this series:
>>>> - Add EFI runtime-safe memset helper and FF-A runtime transport support.
>>>> - Add runtime-safe FF-A direct-message handling and ExitBootServices setup.
>>>> - Implement FF-A runtime communication in the EFI variable TEE backend.
>>>> - Enable EFI runtime SetVariable(), GetVariable(), GetNextVariableName(),
>>>>    and QueryVariableInfo() over the FF-A transport.
>>>> - Add sandbox FF-A runtime transport tests.
>>>> - Extend EFI selftests for runtime variables and enable bootefi selftest
>>>>    on Corstone-1000.
>>>> - Document the FF-A runtime transport and runtime-variable selftest flow.
>>>>
>>>> Changes in v4:
>>>>
>>>> Address Ilias Apalodimas's review comments:
>>>> - Split FF-A bus runtime support into smaller patches covering runtime
>>>>    private data, SMC invocation, direct-message helpers, boot-time reuse,
>>>>    and ExitBootServices setup.
>>>> - Split the ARMv8 cache range-maintenance runtime annotations into a
>>>>    separate patch.
>>>> - Split the EFI variable TEE runtime SetVariable(), GetVariable(),
>>>>    GetNextVariableName(), and QueryVariableInfo() support into separate
>>>>    patches.
>>>> - Replace MM SP status macros with an enum.
>>>> - Keep OP-TEE as the runtime fallback when FF-A runtime mode is not
>>>>    enabled.
>>>>
>>>> Other changes:
>>>> - Rebased the series onto current U-Boot master.
>>>>
>>>> Changes in v3:
>>>>
>>>> Address Simon Glass's review comments:
>>>> - Move FF-A ExitBootServices event registration to the end of probe and
>>>>    clean up RX/TX buffer handling on failure.
>>>> - Rename FF-A runtime-context helpers to the ffa_runtime_context_* form.
>>>> - Rework FF-A/MM cache maintenance to cover only rounded request and
>>>>    response ranges.
>>>> - Add SetVirtualAddressMap handling for the FF-A shared buffer.
>>>> - Document FF-A shared-buffer ownership and alignment assumptions.
>>>> - Add EFIAPI to the TEE runtime GetVariable and GetNextVariableName
>>>>    entry points.
>>>> - Tighten sandbox FF-A runtime tests and reset runtime state between
>>>>    test cases.
>>>> - Update FF-A and bootefi documentation for the runtime transport and
>>>>    split runtime-variable selftests.
>>>> - Rework commit messages to drop redundant information.
>>>>
>>>> Address Ilias Apalodimas's review comments:
>>>> - Keep efi_var_common.c unchanged and drop commit 6 from v2 patchset.
>>>> - Rename the TEE/FF-A runtime handlers to the *_int_runtime form.
>>>> - Remove log_*() calls from __efi_runtime FF-A/MM communication paths.
>>>>
>>>> Other:
>>>> - Fix FF-A memory-share sender_id to use the runtime private endpoint
>>>>    ID after rebasing.
>>>> - Fix the expected QueryVariableInfo() return status for the
>>>>    TEE-backed runtime selftest path.
>>>>
>>>>
>>>> Changes in v2:
>>>>
>>>> Address Simon Glass's review comments:
>>>> - Fix efi_memset_runtime() style, declaration, and byte cast
>>>> - Tighten the FF-A runtime context failure path, clean up arm-ffa-runtime.c
>>>>    style issues, and move ExitBootServices event registration earlier in probe
>>>> - Add shared-buffer bounds/alignment checks, and tightening comments/kernel-doc
>>>> - Document the FF-A shared buffer cacheline-alignment requirement and add
>>>>    BUILD_BUG_ON() checks for the address
>>>> - Cache attributes before the shared buffer is reused, moving the read-only
>>>>    check earlier, and split the u16_strsize() related change in separate patch
>>>> - Reword commit messages for the runtime helper relocation
>>>> - Rework the non-volatile runtime variable selftest into setup/verify phases
>>>> - Extend the sandbox FF-A runtime tests with no-context coverage,
>>>>    runtime-context reset, and separate errno-mapping coverage
>>>> - Refresh the FF-A runtime transport and bootefi documentation
>>>> - Drop patch 12 in v1, as ffa_mm_communicate handles both runtime and
>>>>    boottime capabilities in v2
>>>> - Squash patch 8 and patch 9 from v1
>>>>
>>>> Address Ilias Apalodimas's review comments:
>>>> - Reuse common MM SP error mapping for boot and runtime paths
>>>> - Rename runtime-phase tracking to reflect the ExitBootServices transition
>>>> - Collapse duplicated boot-time and runtime MM communication helpers into common
>>>>    implementations
>>>> - Keep the arm64 cache-maintenance path runtime-safe
>>>> - Move FF-A shared-buffer runtime memory-map registration to the end of
>>>>    variable-service initialization
>>>>
>>>> Link to v3: https://lore.kernel.org/u-boot/20260627144421.2067410-1-harsimransingh.tungal@arm.com/
>>>> Link to v2: https://lore.kernel.org/u-boot/20260514124924.1804332-1-harsimransingh.tungal@arm.com/
>>>> Link to v1: https://lore.kernel.org/u-boot/20260424173151.371134-1-harsimransingh.tungal@arm.com/
>>>>
>>>> Harsimran Singh Tungal (22):
>>>>    efi_loader: add runtime memset helper
>>>>    arm-ffa: store boot-discovered runtime data separately
>>>>    arm-ffa: add runtime-safe FF-A SMC wrapper
>>>>    arm-ffa: add runtime direct-message support
>>>>    arm-ffa: reuse direct-message helper at boot time
>>>>    arm-ffa: enable runtime context at ExitBootServices
>>>>    arm: cache: keep range maintenance available at EFI runtime
>>>>    efi_loader: add MM SP status mapping for FF-A variables
>>>>    efi_loader: make MM transport selection runtime-safe
>>>>    efi_loader: make FF-A MM SP notification runtime-safe
>>>>    efi_loader: make FF-A MM communication runtime-safe
>>>>    efi_loader: reserve FF-A shared buffer for runtime variables
>>>>    efi_loader: enable TEE runtime SetVariable() over FF-A
>>>>    efi_loader: enable TEE runtime GetVariable() over FF-A
>>>>    efi_loader: enable TEE runtime GetNextVariableName() over FF-A
>>>>    efi_loader: enable TEE runtime QueryVariableInfo() over FF-A
>>>>    charset: mark u16_strsize() as __efi_runtime
>>>>    corstone1000: enable bootefi selftest
>>>>    efi: selftest: add runtime variable tests with non-volatile storage
>>>>    test: dm: add sandbox FF-A runtime transport tests
>>>>    doc: arm64: document FF-A runtime path for EFI variables
>>>>    doc: bootefi: note two-phase runtime variables selftest
>>>>
>>>>   arch/arm/cpu/armv8/cache.S                    |   8 +
>>>>   arch/arm/cpu/armv8/cache_v8.c                 |  13 +-
>>>>   arch/sandbox/include/asm/sandbox_arm_ffa.h    |  16 +-
>>>>   configs/corstone1000_defconfig                |   3 +
>>>>   doc/arch/arm64.ffa.rst                        |  88 ++-
>>>>   doc/usage/cmd/armffa.rst                      |  11 +
>>>>   doc/usage/cmd/bootefi.rst                     |  31 +
>>>>   drivers/firmware/arm-ffa/Kconfig              |  11 +
>>>>   drivers/firmware/arm-ffa/Makefile             |   4 +-
>>>>   drivers/firmware/arm-ffa/arm-ffa-runtime.c    | 294 +++++++
>>>>   drivers/firmware/arm-ffa/arm-ffa-uclass.c     | 114 +--
>>>>   drivers/firmware/arm-ffa/arm-ffa.c            |  16 +-
>>>>   drivers/firmware/arm-ffa/ffa-emul-uclass.c    |  49 +-
>>>>   include/arm_ffa.h                             |  16 +-
>>>>   include/arm_ffa_priv.h                        |  22 +-
>>>>   include/arm_ffa_runtime.h                     | 191 +++++
>>>>   include/efi_loader.h                          |   3 +
>>>>   lib/charset.c                                 |   2 +-
>>>>   lib/efi_loader/Kconfig                        |   4 +
>>>>   lib/efi_loader/efi_runtime.c                  |  20 +
>>>>   lib/efi_loader/efi_variable_tee.c             | 739 +++++++++++++++---
>>>>   .../efi_selftest_variables_runtime.c          | 715 +++++++++++------
>>>>   test/dm/Makefile                              |   3 +-
>>>>   test/dm/ffa.c                                 |   6 +-
>>>>   test/dm/ffa_runtime.c                         | 123 +++
>>>>   25 files changed, 2004 insertions(+), 498 deletions(-)
>>>>   create mode 100644 drivers/firmware/arm-ffa/arm-ffa-runtime.c
>>>>   create mode 100644 include/arm_ffa_runtime.h
>>>>   create mode 100644 test/dm/ffa_runtime.c
>>>>
>>>> --
>>>> 2.34.1
>>>>

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