On 2026-04-25 00:18 +0200, Heinrich Schuchardt wrote: > Am 24. April 2026 19:31:39 MESZ schrieb Harsimran Singh Tungal > <[email protected]>: > >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, docs, and board configs to validate the runtime > >path and keep boot‑time behavior aligned with the runtime flow. > > Hello Harsiman, > > Could you, please, explain the motivation for the series. > > What is the overall architecture? > > Please, describe how to set up a system on QEMU to test your development > including the instructions for the secure world. > > We would need a test in the CI using QEMU. > > Best regards > > Heinrich > > Hi Heinrich,
The motivation for the series is that, when EFI variables are backed by an MM Secure Partition reached over FF-A, U-Boot can use that path during boot, but after ExitBootServices() the normal FF-A/DM path is no longer suitable. As a result, EFI runtime variable services can no longer reach the secure partition. The goal of this series is to keep only the minimal FF-A transport needed for EFI runtime variable services available after ExitBootServices(). The overall architecture is: - During boot, the FF-A bus probes normally, discovers the U-Boot endpoint ID and the MM SP partition ID, and registers an ExitBootServices() callback. - At ExitBootServices(), U-Boot copies the minimal FF-A state needed at runtime into resident runtime data and enables the runtime context. - After that, EFI runtime variable operations (SetVariable/GetVariable/GetNextVariableName/QueryVariableInfo) use the runtime-safe path in efi_variable_tee.c, reuse the fixed FF-A shared buffer, perform range-based cache maintenance on that buffer only, and notify the MM SP using FF-A direct messaging. So the runtime side is intentionally narrow: it keeps just enough FF-A support for EFI runtime variables, rather than trying to preserve the full FF-A bus or driver-model stack after ExitBootServices(). On testing, the current series adds sandbox DM tests for the FF-A runtime helpers and EFI selftests for the runtime variable path, and my end-to-end validation so far has been on Corstone-1000. I do not have a proper QEMU setup with the corresponding secure-world/MM SP side packaged as part of this series, so I cannot provide good QEMU instructions. More details on building and running Corstone-1000 FVP can be found here: https://corstone1000.docs.arm.com/en/latest/user-guide.html Please let me know if this overall direction makes sense to you. Regards Harsimran Singh Tungal > > > >Changes in this series: > >- Add EFI runtime-safe memset helper and FF-A runtime transport support. > >- Implement FF-A runtime communication in the EFI variable TEE backend. > >- Enable runtime variable operations and move helpers to avoid conflicts. > >- Add sandbox runtime transport tests and metadata reuse. > >- Extend EFI selftests for runtime variables and bootefi selftest config. > >- Document the FF-A runtime transport and selftest behavior. > >- Align boot‑time cache maintenance with the runtime path. > > > >Harsimran Singh Tungal (12): > > efi_loader: add runtime memset helper > > arm-ffa: add FF-A bus runtime support > > efi_loader: add FF-A runtime support in EFI variable TEE driver > > efi_loader: enable EFI runtime SetVariable()/GetVariable() using FF-A > > transport > > efi_loader: move runtime GetVariable() helpers to efi_variable.c > > corstone1000: enable bootefi selftest > > efi: selftest: add runtime variable tests with non-volatile storage > > test: dm: add sandbox FF-A runtime transport tests > > sandbox: ffa: share synthetic partition metadata via macros > > doc: arm64: document FF-A runtime path for EFI variables > > doc: bootefi: note two-phase runtime variables selftest > > efi_loader: align FF-A cache maintenance with runtime path > > > > arch/sandbox/include/asm/sandbox_arm_ffa.h | 16 +- > > configs/corstone1000_defconfig | 3 + > > doc/arch/arm64.ffa.rst | 92 ++- > > doc/usage/cmd/armffa.rst | 11 + > > doc/usage/cmd/bootefi.rst | 12 + > > drivers/firmware/arm-ffa/Kconfig | 11 + > > drivers/firmware/arm-ffa/Makefile | 4 +- > > drivers/firmware/arm-ffa/arm-ffa-runtime.c | 287 ++++++++ > > drivers/firmware/arm-ffa/arm-ffa-uclass.c | 111 +-- > > drivers/firmware/arm-ffa/arm-ffa.c | 16 +- > > drivers/firmware/arm-ffa/ffa-emul-uclass.c | 48 +- > > include/arm_ffa.h | 16 +- > > include/arm_ffa_priv.h | 24 +- > > include/arm_ffa_runtime.h | 183 +++++ > > include/efi_loader.h | 3 + > > lib/charset.c | 2 +- > > lib/efi_loader/efi_runtime.c | 21 + > > lib/efi_loader/efi_var_common.c | 24 - > > lib/efi_loader/efi_variable.c | 24 + > > lib/efi_loader/efi_variable_tee.c | 686 +++++++++++++++++- > > .../efi_selftest_variables_runtime.c | 106 ++- > > test/dm/Makefile | 3 +- > > test/dm/ffa.c | 6 +- > > test/dm/ffa_runtime.c | 82 +++ > > 24 files changed, 1602 insertions(+), 189 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 > > > >
