[PATCH v4 09/10] RISC-V: KVM: Allow Zalasr extensions for Guest/VM

[Anup Patel]

On Mon, Oct 20, 2025 at 9:55 AM Xu Lu <luxu.kernel at bytedance.com> wrote:
>
> Extend the KVM ISA extension ONE_REG interface to allow KVM user space
> to detect and enable Zalasr extensions for Guest/VM.
>
> Signed-off-by: Xu Lu <luxu.kernel at bytedance.com>

LGTM.

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

Queued this patch for Linux-6.20

Thanks,
Anup

> ---
>  arch/riscv/include/uapi/asm/kvm.h | 1 +
>  arch/riscv/kvm/vcpu_onereg.c      | 2 ++
>  2 files changed, 3 insertions(+)
>
> diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
> index ef27d4289da11..4fbc32ef888fa 100644
> --- a/arch/riscv/include/uapi/asm/kvm.h
> +++ b/arch/riscv/include/uapi/asm/kvm.h
> @@ -185,6 +185,7 @@ enum KVM_RISCV_ISA_EXT_ID {
>         KVM_RISCV_ISA_EXT_ZICCRSE,
>         KVM_RISCV_ISA_EXT_ZAAMO,
>         KVM_RISCV_ISA_EXT_ZALRSC,
> +       KVM_RISCV_ISA_EXT_ZALASR,
>         KVM_RISCV_ISA_EXT_MAX,
>  };
>
> diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c
> index cce6a38ea54f2..6ae5f9859f25b 100644
> --- a/arch/riscv/kvm/vcpu_onereg.c
> +++ b/arch/riscv/kvm/vcpu_onereg.c
> @@ -50,6 +50,7 @@ static const unsigned long kvm_isa_ext_arr[] = {
>         KVM_ISA_EXT_ARR(ZAAMO),
>         KVM_ISA_EXT_ARR(ZABHA),
>         KVM_ISA_EXT_ARR(ZACAS),
> +       KVM_ISA_EXT_ARR(ZALASR),
>         KVM_ISA_EXT_ARR(ZALRSC),
>         KVM_ISA_EXT_ARR(ZAWRS),
>         KVM_ISA_EXT_ARR(ZBA),
> @@ -184,6 +185,7 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
>         case KVM_RISCV_ISA_EXT_ZAAMO:
>         case KVM_RISCV_ISA_EXT_ZABHA:
>         case KVM_RISCV_ISA_EXT_ZACAS:
> +       case KVM_RISCV_ISA_EXT_ZALASR:
>         case KVM_RISCV_ISA_EXT_ZALRSC:
>         case KVM_RISCV_ISA_EXT_ZAWRS:
>         case KVM_RISCV_ISA_EXT_ZBA:
> --
> 2.20.1
>