Re: [PATCH v3 1/2] x86/cpufeatures: Add "Allowed SEV Features" Feature

Tom Lendacky
2025-02-10T17:20:26Z

On 2/7/25 17:34, Kim Phillips wrote:
> From: Kishon Vijay Abraham I <kvijayab@amd.com>
>
> Add CPU feature detection for "Allowed SEV Features" to allow the
> Hypervisor to enforce that SEV-ES and SEV-SNP guest VMs cannot
> enable features (via SEV_FEATURES) that the Hypervisor does not
> support or wish to be enabled.
>
> Signed-off-by: Kishon Vijay Abraham I <kvijayab@amd.com>
> Signed-off-by: Kim Phillips <kim.phillips@amd.com>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
> arch/x86/include/asm/cpufeatures.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> index 508c0dad116b..a80a4164d110 100644
> --- a/arch/x86/include/asm/cpufeatures.h
> +++ b/arch/x86/include/asm/cpufeatures.h
> @@ -453,6 +453,7 @@
> #define X86_FEATURE_DEBUG_SWAP (19*32+14) /* "debug_swap" SEV-ES full debug state swap support */
> #define X86_FEATURE_RMPREAD (19*32+21) /* RMPREAD instruction */
> #define X86_FEATURE_SEGMENTED_RMP (19*32+23) /* Segmented RMP support */
> +#define X86_FEATURE_ALLOWED_SEV_FEATURES (19*32+27) /* Allowed SEV Features */
> #define X86_FEATURE_SVSM (19*32+28) /* "svsm" SVSM present */
> #define X86_FEATURE_HV_INUSE_WR_ALLOWED (19*32+30) /* Allow Write to in-use hypervisor-owned pages */
>