[PATCH v2 0/2] KVM: SVM: Handle EferLmsleUnsupported

Jim Mattson
2025-10-01T00:15:38Z

It is no longer the case that EFER.LMSLE is supported by all SVM-capable
processors. AMD enumerates the absence of this feature by CPUID
Fn8000_0008_EBX[EferLmlseUnsupported](bit 20)=1.

Advertise this defeature bit to userspace via KVM_GET_SUPPORTED_CPUID,
and don't allow a guest to set EFER.LMSLE on hardware that doesn't
support the feature.

Jim Mattson (2):
KVM: x86: Advertise EferLmsleUnsupported to userspace
KVM: SVM: Disallow EFER.LMSLE when not supported by hardware

arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/kvm/cpuid.c | 1 +
arch/x86/kvm/svm/svm.c | 4 +++-
3 files changed, 5 insertions(+), 1 deletion(-)

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2.51.0.618.g983fd99d29-goog