[PATCH] KVM: x86: Use cpu_feature_enabled() for PKU instead of #ifdef

From: Sean Christopherson
Date: Thu Jun 01 2023 - 21:06:01 EST


Replace an #ifdef on CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS with a
cpu_feature_enabled() check on X86_FEATURE_PKU. The macro magic of
DISABLED_MASK_BIT_SET() means that cpu_feature_enabled() provides the
same end result (no code generated) when PKU is disabled by Kconfig.

No functional change intended.

Cc: Jon Kohler <jon@xxxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ceb7c5e9cf9e..eed1f0629023 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1017,13 +1017,11 @@ void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu)
wrmsrl(MSR_IA32_XSS, vcpu->arch.ia32_xss);
}

-#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
- if (static_cpu_has(X86_FEATURE_PKU) &&
+ if (cpu_feature_enabled(X86_FEATURE_PKU) &&
vcpu->arch.pkru != vcpu->arch.host_pkru &&
((vcpu->arch.xcr0 & XFEATURE_MASK_PKRU) ||
kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE)))
write_pkru(vcpu->arch.pkru);
-#endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */
}
EXPORT_SYMBOL_GPL(kvm_load_guest_xsave_state);

@@ -1032,15 +1030,13 @@ void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu)
if (vcpu->arch.guest_state_protected)
return;

-#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
- if (static_cpu_has(X86_FEATURE_PKU) &&
+ if (cpu_feature_enabled(X86_FEATURE_PKU) &&
((vcpu->arch.xcr0 & XFEATURE_MASK_PKRU) ||
kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE))) {
vcpu->arch.pkru = rdpkru();
if (vcpu->arch.pkru != vcpu->arch.host_pkru)
write_pkru(vcpu->arch.host_pkru);
}
-#endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */

if (kvm_is_cr4_bit_set(vcpu, X86_CR4_OSXSAVE)) {


base-commit: a053a0e4a9f8c52f3acf8a9d2520c4bf39077a7e
--
2.41.0.rc2.161.g9c6817b8e7-goog