Re: [PATCH 1/3] KVM: x86: Rename supports_cpuid_fault to supports_intel_cpuid_fault

[Sean Christopherson]

On Thu, Apr 02, 2026, Jim Mattson wrote:
> The function, supports_cpuid_fault(), tests for guest support of Intel's
> CPUID faulting feature. Rename the function to supports_intel_cpuid_fault()
> for clarity.
> 
> Signed-off-by: Jim Mattson <jmatt...@google.com>
> ---
>  arch/x86/kvm/cpuid.h | 2 +-
>  arch/x86/kvm/x86.c   | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
> index 039b8e6f40ba..51cbe67c992a 100644
> --- a/arch/x86/kvm/cpuid.h
> +++ b/arch/x86/kvm/cpuid.h
> @@ -181,7 +181,7 @@ static inline int guest_cpuid_stepping(struct kvm_vcpu 
> *vcpu)
>       return x86_stepping(best->eax);
>  }
>  
> -static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
> +static inline bool supports_intel_cpuid_fault(struct kvm_vcpu *vcpu)

*sigh*

I was going to suggest supports_misc_enables_cpuid_fault(), since KVM emulates
the MSR for all CPU vendors, but the enable is in MISC_FEATURE_ENABLES, not
IA32_MISC_ENABLES.

What if we just drop the helper?  There's only one user.  I.e.

diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 039b8e6f40ba..8b64d863e19c 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -181,11 +181,6 @@ static inline int guest_cpuid_stepping(struct kvm_vcpu 
*vcpu)
        return x86_stepping(best->eax);
 }
 
-static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
-{
-       return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT;
-}
-
 static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu)
 {
        return vcpu->arch.msr_misc_features_enables &
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2410401c57d8..c72ea99422ca 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4262,7 +4262,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct 
msr_data *msr_info)
        case MSR_MISC_FEATURES_ENABLES:
                if (data & ~MSR_MISC_FEATURES_ENABLES_CPUID_FAULT ||
                    (data & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT &&
-                    !supports_cpuid_fault(vcpu)))
+                    !(vcpu->arch.msr_platform_info & 
MSR_PLATFORM_INFO_CPUID_FAULT)))
                        return 1;
                vcpu->arch.msr_misc_features_enables = data;
                break;