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From: Jim Mattson <jmattson@google.com>
To: seanjc@google.com, pbonzini@redhat.com, tglx@kernel.org,
	mingo@redhat.com,  bp@alien8.de, dave.hansen@linux.intel.com,
	x86@kernel.org, hpa@zytor.com,  shuah@kernel.org,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	 linux-kselftest@vger.kernel.org, ctpence@google.com,
	David.Kaplan@amd.com,  binbin.wu@linux.intel.com
Cc: Jim Mattson <jmattson@google.com>
Subject: [PATCH v4 3/5] KVM: x86: Remove supports_cpuid_fault() helper
Date: Wed, 27 May 2026 10:43:45 -0700	[thread overview]
Message-ID: <20260527174347.2356165-4-jmattson@google.com> (raw)
In-Reply-To: <20260527174347.2356165-1-jmattson@google.com>

The function, supports_cpuid_fault(), tests specifically for guest support
of Intel's CPUID faulting feature. It does not test for guest support of
AMD's CPUID faulting feature.

To avoid confusion, remove the helper.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
---
 arch/x86/kvm/cpuid.h | 5 -----
 arch/x86/kvm/x86.c   | 2 +-
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index bc4a8428b836..95d09ccbf951 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -183,11 +183,6 @@ 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 72bd3cddb026..d5a2d794c3c9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4264,7 +4264,7 @@ 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;
-- 
2.54.0.794.g4f17f83d09-goog


  parent reply	other threads:[~2026-05-27 17:44 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-27 17:43 [PATCH v4 0/5] KVM: x86: Virtualize AMD's "disable CPUID in usermode" Jim Mattson
2026-05-27 17:43 ` [PATCH v4 1/5] KVM: x86: Consolidate CPUID fault handling for emulator and interception logic Jim Mattson
2026-05-28  9:13   ` Peter Zijlstra
2026-05-28 14:20     ` Jim Mattson
2026-05-28 16:08       ` Sean Christopherson
2026-05-28 16:06     ` Sean Christopherson
2026-05-27 17:43 ` [PATCH v4 2/5] KVM: x86: Prioritize CPUID faulting over CPUID VM-exits in nested VMX Jim Mattson
2026-05-27 17:43 ` Jim Mattson [this message]
2026-05-27 17:43 ` [PATCH v4 4/5] KVM: x86: Virtualize AMD CPUID faulting Jim Mattson
2026-05-27 17:43 ` [PATCH v4 5/5] KVM: selftests: Update hwcr_msr_test for CPUID faulting bit Jim Mattson
2026-05-29 22:47 ` [PATCH v4 0/5] KVM: x86: Virtualize AMD's "disable CPUID in usermode" Sean Christopherson
2026-06-06 15:12   ` Jim Mattson
2026-06-06 16:00     ` Jim Mattson

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