Re: [PATCH v5 1/5] KVM: RISC-V: SBI FWFT: Mark vCPU CSRs dirty after setting feature value

[Anup Patel]

On Mon, Jun 1, 2026 at 3:56 PM Yong-Xuan Wang <yongxuan.w...@sifive.com> wrote:
>
> Mark the vCPU CSRs as dirty after successfully setting an FWFT feature
> value. FWFT features may modify CSRs (e.g., pointer masking modifies
> henvcfg.PMM), and failing to mark them dirty can lead to the guest
> observing stale CSR state after vCPU scheduling or migration.
>
> Fixes: 1323a5cfe52c ("KVM: riscv: Skip CSR restore if VCPU is reloaded on the 
> same core")
>
> Signed-off-by: Yong-Xuan Wang <yongxuan.w...@sifive.com>

LGTM.

Reviewed-by: Anup Patel <a...@brainfault.org>

Thanks,
Anup

> ---
>  arch/riscv/kvm/vcpu_sbi_fwft.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c
> index 2eab15339694..5e4aafb0cbf1 100644
> --- a/arch/riscv/kvm/vcpu_sbi_fwft.c
> +++ b/arch/riscv/kvm/vcpu_sbi_fwft.c
> @@ -521,6 +521,7 @@ static int kvm_sbi_ext_fwft_set_reg(struct kvm_vcpu 
> *vcpu, unsigned long reg_num
>                 break;
>         case 2:
>                 ret = conf->feature->set(vcpu, conf, true, value);
> +               vcpu->arch.csr_dirty = true;
>                 break;
>         default:
>                 return -ENOENT;
>
> --
> 2.43.7
>