From 35b7cde8ddf1c374c533ec0de2958d2cd74e587d Mon Sep 17 00:00:00 2001 From: Jim Mattson Date: Fri, 7 Oct 2022 15:16:44 -0700 Subject: [PATCH 29/36] KVM: x86: Advertise that the SMM_CTL MSR is not supported CPUID.80000021H:EAX[bit 9] indicates that the SMM_CTL MSR (0xc0010116) is not supported. This defeature can be advertised by KVM_GET_SUPPORTED_CPUID regardless of whether or not the host enumerates it; currently it will be included only if the host enumerates at least leaf 8000001DH, due to a preexisting bug in QEMU that KVM has to work around (commit f751d8eac176, "KVM: x86: work around QEMU issue with synthetic CPUID leaves", 2022-04-29). Signed-off-by: Jim Mattson Message-Id: <20221007221644.138355-1-jmattson@google.com> Signed-off-by: Paolo Bonzini (cherry picked from commit 74bee0cad8dcd8ddec5e763c369239fc5990676a) Signed-off-by: Mridula Shastry Reviewed-by: Todd Vierling --- arch/x86/kvm/cpuid.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 6e3f385a3648..3726861ae52a 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -1180,8 +1180,12 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) * Other defined bits are for MSRs that KVM does not expose: * EAX 3 SPCL, SMM page configuration lock * EAX 13 PCMSR, Prefetch control MSR + * + * KVM doesn't support SMM_CTL. + * EAX 9 SMM_CTL MSR is not supported */ entry->eax &= BIT(0) | BIT(2) | BIT(6); + entry->eax |= BIT(9); if (static_cpu_has(X86_FEATURE_LFENCE_RDTSC)) entry->eax |= BIT(2); if (!static_cpu_has_bug(X86_BUG_NULL_SEG)) -- 2.39.3