[PATCH v9 3/3] RISC-V: KVM: selftests: Add RISC-V SBI STA shmem alignment tests

[Andrew Jones]

On Sat, Feb 28, 2026 at 12:53:55AM +0000, Jiakai Xu wrote:
> Add RISC-V KVM selftests to verify the SBI Steal-Time Accounting (STA)
> shared memory alignment requirements.
> 
> The SBI specification requires the STA shared memory GPA to be 64-byte
> aligned, or set to all-ones to explicitly disable steal-time accounting.
> This test verifies that KVM enforces the expected behavior when
> configuring the SBI STA shared memory via KVM_SET_ONE_REG.
> 
> Specifically, the test checks that:
> - misaligned GPAs are rejected with -EINVAL
> - 64-byte aligned GPAs are accepted
> - all-ones GPA is accepted
> 
> Signed-off-by: Jiakai Xu <xujiakai2025 at iscas.ac.cn>
> Signed-off-by: Jiakai Xu <jiakaiPeanut at gmail.com>
> ---
> V8 -> V9: Dropped __riscv guard around INVALID_GPA, which is common to
>            all architectures.
> V7 -> V8: Moved INVALID_GPA definition to kvm_util_types.h.
>           Removed comments in RISC-V check_steal_time_uapi().
>           Corrected reg.id assignment for SBI STA.
> V6 -> V7: Removed RISCV_SBI_STA_REG() macro addition and used existing
>            KVM_REG_RISCV_SBI_STA_REG(shmem_lo) instead.
>           Refined assertion messages per review feedback.
>           Split into two patches per Andrew Jones' suggestion:
>            Refactored UAPI tests from steal_time_init() into dedicated
>             check_steal_time_uapi() function and added empty stub for
>             RISC-V.
>            Filled in RISC-V stub with STA alignment tests. (this patch)
> ---
>  .../selftests/kvm/include/kvm_util_types.h    |  2 ++
>  tools/testing/selftests/kvm/steal_time.c      | 31 +++++++++++++++++++
>  2 files changed, 33 insertions(+)
>

Reviewed-by: Andrew Jones <andrew.jones at oss.qualcomm.com>