linux-kernel - [PATCH v2 3/3] KVM: SVM: Unconditionally enumerate EferLmsleUnsupported

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Date:   Tue, 20 Sep 2022 13:59:22 -0700
From:   Jim Mattson <jmattson@...gle.com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        "H . Peter Anvin" <hpa@...or.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Jim Mattson <jmattson@...gle.com>
Subject: [PATCH v2 3/3] KVM: SVM: Unconditionally enumerate EferLmsleUnsupported

CPUID.80000008H:EDX.EferLmsleUnsupported[bit 20] indicates that
IA32_EFER.LMSLE[bit 13] is unsupported and must be zero.

KVM doesn't support "Long Mode Segment Limit Enable," even if the
underlying physical processor does, so set that bit in the guest CPUID
table returned by KVM_GET_SUPPORTED_CPUID.

Signed-off-by: Jim Mattson <jmattson@...gle.com>
---
 arch/x86/kvm/svm/svm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 3af360fe21e6..0bf6ac51f097 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4945,6 +4945,7 @@ static __init void svm_set_cpu_caps(void)
 	if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) ||
 	    boot_cpu_has(X86_FEATURE_AMD_SSBD))
 		kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD);
+	kvm_cpu_cap_set(X86_FEATURE_NO_LMSLE);
 
 	/* AMD PMU PERFCTR_CORE CPUID */
 	if (enable_pmu && boot_cpu_has(X86_FEATURE_PERFCTR_CORE))
-- 
2.37.3.968.ga6b4b080e4-goog