linux-kernel - [PATCH v3 12/16] KVM: selftests: Allow kvm_cpu_has

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Message-ID: <20251127013440.3324671-13-yosry.ahmed@linux.dev>
Date: Thu, 27 Nov 2025 01:34:36 +0000
From: Yosry Ahmed <yosry.ahmed@...ux.dev>
To: Sean Christopherson <seanjc@...gle.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>,
	kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Yosry Ahmed <yosry.ahmed@...ux.dev>
Subject: [PATCH v3 12/16] KVM: selftests: Allow kvm_cpu_has_ept() to be called on AMD CPUs

In preparation for generalizing the nested dirty logging test, checking
if either EPT or NPT is enabled will be needed. To avoid needing to gate
the kvm_cpu_has_ept() call by the CPU type, make sure the function
returns false if VMX is not available instead of trying to read VMX-only
MSRs.

No functional change intended.

Signed-off-by: Yosry Ahmed <yosry.ahmed@...ux.dev>
---
 tools/testing/selftests/kvm/lib/x86/vmx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/x86/vmx.c b/tools/testing/selftests/kvm/lib/x86/vmx.c
index 4289c9eb61ff..f70d0d591d5a 100644
--- a/tools/testing/selftests/kvm/lib/x86/vmx.c
+++ b/tools/testing/selftests/kvm/lib/x86/vmx.c
@@ -380,6 +380,9 @@ bool kvm_cpu_has_ept(void)
 {
 	uint64_t ctrl;
 
+	if (!kvm_cpu_has(X86_FEATURE_VMX))
+		return false;
+
 	ctrl = kvm_get_feature_msr(MSR_IA32_VMX_TRUE_PROCBASED_CTLS) >> 32;
 	if (!(ctrl & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS))
 		return false;
-- 
2.52.0.158.g65b55ccf14-goog