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 <jmattson@google.com>
Message-Id: <
20221007221644.138355-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* 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))