[PATCH 1/2] riscv: kvm: return SBI_ERR_FAILURE for pmu_snapshot_set_shmem OOM

[Anup Patel]

On Thu, May 14, 2026 at 11:06 PM Osama Abdelkader
<osama.abdelkader at gmail.com> wrote:
>
> kvm_riscv_vcpu_pmu_snapshot_set_shmem() returned -ENOMEM from the
> SBI extension handler, which caused kvm_riscv_vcpu_sbi_ecall() to
> abort KVM_RUN and surface the error to userspace instead of
> ompleting the ECALL with a negative SBI error in a0.
> Use SBI_ERR_FAILURE and the normal retdata path, matching other PMU
> handlers and kvm_sbi_ext_pmu_handler comment.
>
> Fixes: c2f41ddbcdd7 ("RISC-V: KVM: Implement SBI PMU Snapshot feature")
> Cc: stable at vger.kernel.org
> Signed-off-by: Osama Abdelkader <osama.abdelkader at gmail.com>

LGTM.

Reviewed-by: Anup Patel <anup at brainfault.org>

Queued this as fix for Linux-7.1-rcX

Thanks,
Anup


> ---
>  arch/riscv/kvm/vcpu_pmu.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
> index a935ed96bc17..91aa0155a420 100644
> --- a/arch/riscv/kvm/vcpu_pmu.c
> +++ b/arch/riscv/kvm/vcpu_pmu.c
> @@ -453,8 +453,10 @@ int kvm_riscv_vcpu_pmu_snapshot_set_shmem(struct kvm_vcpu *vcpu, unsigned long s
>         }
>
>         kvpmu->sdata = kzalloc(snapshot_area_size, GFP_ATOMIC);
> -       if (!kvpmu->sdata)
> -               return -ENOMEM;
> +       if (!kvpmu->sdata) {
> +               sbiret = SBI_ERR_FAILURE;
> +               goto out;
> +       }
>
>         /* No need to check writable slot explicitly as kvm_vcpu_write_guest does it internally */
>         if (kvm_vcpu_write_guest(vcpu, saddr, kvpmu->sdata, snapshot_area_size)) {
> --
> 2.43.0
>