Re: [PATCH v2 3/4] x86: Expose SERIALIZE for supported cpuid

[Sean Christopherson <sean.j.christopherson@intel.com>]

On Tue, Jul 07, 2020 at 10:16:22AM +0800, Cathy Zhang wrote:
> SERIALIZE instruction is supported by intel processors,
> like Sapphire Rapids. Expose it in KVM supported cpuid.

Providing at least a rough overview of the instruction, e.g. its enumeration,
usage, fault rules, controls, etc... would be nice.  In isolation, the
changelog isn't remotely helpful in understanding the correctness of the
patch.

> Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
> ---
>  arch/x86/kvm/cpuid.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 8a294f9..e603aeb 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -341,7 +341,8 @@ void kvm_set_cpu_caps(void)
>  	kvm_cpu_cap_mask(CPUID_7_EDX,
>  		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
>  		F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
> -		F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM)
> +		F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM) |
> +		F(SERIALIZE)
>  	);
>  
>  	/* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */
> -- 
> 1.8.3.1
>