diff mbox series

[v2,42/49] KVM: x86: Drop unnecessary check that cpuid_entry2_find() returns right leaf

Message ID 20240517173926.965351-43-seanjc@google.com (mailing list archive)
State New, archived
Headers show
Series KVM: x86: CPUID overhaul, fixes, and caching | expand

Commit Message

Sean Christopherson May 17, 2024, 5:39 p.m. UTC 
Drop an unnecessary check that kvm_find_cpuid_entry_index(), i.e.
cpuid_entry2_find(), returns the correct leaf when getting CPUID.0x7.0x0
to update X86_FEATURE_OSPKE.  cpuid_entry2_find() never returns an entry
for the wrong function.  And not that it matters, but cpuid_entry2_find()
will always return a precise match for CPUID.0x7.0x0 since the index is
significant.

No functional change intended.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/cpuid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Maxim Levitsky July 5, 2024, 2:22 a.m. UTC | #1 
On Fri, 2024-05-17 at 10:39 -0700, Sean Christopherson wrote:
> Drop an unnecessary check that kvm_find_cpuid_entry_index(), i.e.
> cpuid_entry2_find(), returns the correct leaf when getting CPUID.0x7.0x0
> to update X86_FEATURE_OSPKE.  cpuid_entry2_find() never returns an entry
> for the wrong function.  And not that it matters, but cpuid_entry2_find()
> will always return a precise match for CPUID.0x7.0x0 since the index is
> significant.
> 
> No functional change intended.
> 
> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  arch/x86/kvm/cpuid.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 258c5fce87fc..8256fc657c6b 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -351,7 +351,7 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
>  	}
>  
>  	best = kvm_find_cpuid_entry_index(vcpu, 7, 0);
> -	if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7)
> +	if (best && boot_cpu_has(X86_FEATURE_PKU))
>  		cpuid_entry_change(best, X86_FEATURE_OSPKE,
>  				   kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE));
>  

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>

Best regards,
	Maxim Levitsky
diff mbox series

Patch

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 258c5fce87fc..8256fc657c6b 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -351,7 +351,7 @@  void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
 	}
 
 	best = kvm_find_cpuid_entry_index(vcpu, 7, 0);
-	if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7)
+	if (best && boot_cpu_has(X86_FEATURE_PKU))
 		cpuid_entry_change(best, X86_FEATURE_OSPKE,
 				   kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE));