Re: [PATCH v7 19/26] KVM: x86: Use KVM-governed feature framework to track "SHSTK/IBT enabled"

[Maxim Levitsky]

On Fri, 2023-11-24 at 00:53 -0500, Yang Weijiang wrote:
> Use the governed feature framework to track whether X86_FEATURE_SHSTK
> and X86_FEATURE_IBT features can be used by userspace and guest, i.e.,
> the features can be used iff both KVM and guest CPUID can support them.
> 
> TODO: remove this patch once Sean's refactor to "KVM-governed" framework
> is upstreamed. See the work here [*].
> 
> [*]: https://lore.kernel.org/all/20231110235528.1561679-1-seanjc@xxxxxxxxxx/
> 
> Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx>
> ---
>  arch/x86/kvm/governed_features.h | 2 ++
>  arch/x86/kvm/vmx/vmx.c           | 2 ++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h
> index 423a73395c10..db7e21c5ecc2 100644
> --- a/arch/x86/kvm/governed_features.h
> +++ b/arch/x86/kvm/governed_features.h
> @@ -16,6 +16,8 @@ KVM_GOVERNED_X86_FEATURE(PAUSEFILTER)
>  KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD)
>  KVM_GOVERNED_X86_FEATURE(VGIF)
>  KVM_GOVERNED_X86_FEATURE(VNMI)
> +KVM_GOVERNED_X86_FEATURE(SHSTK)
> +KVM_GOVERNED_X86_FEATURE(IBT)
>  
>  #undef KVM_GOVERNED_X86_FEATURE
>  #undef KVM_GOVERNED_FEATURE
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index d3d0d74fef70..f6ad5ba5d518 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7762,6 +7762,8 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
>  		kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_XSAVES);
>  
>  	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_VMX);
> +	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_SHSTK);
> +	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_IBT);
>  
>  	vmx_setup_uret_msrs(vmx);
>  

Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>

Best regards,
	Maxim Levitsky