diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index a4d24d04f0b1..17e372de7ee8 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -1213,7 +1213,8 @@ static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_array *array, return entry; } -static int cpuid_func_emulated(struct kvm_cpuid_entry2 *entry, u32 func) +static int cpuid_func_emulated(struct kvm_cpuid_entry2 *entry, u32 func, + bool include_partially_emulated) { memset(entry, 0, sizeof(*entry)); @@ -1227,6 +1228,16 @@ static int cpuid_func_emulated(struct kvm_cpuid_entry2 *entry, u32 func) return 1; case 1: entry->ecx = feature_bit(MOVBE); + /* + * KVM allows userspace to enumerate MONITOR+MWAIT support to + * the guest, but the MWAIT feature flag is never advertised + * to userspace because MONITOR+MWAIT aren't virtualized by + * hardware, can't be faithfully emulated in software (KVM + * emulates them as NOPs), and allowing the guest to execute + * them natively requires enabling a per-VM capability. + */ + if (include_partially_emulated) + entry->ecx |= feature_bit(MWAIT); return 1; case 7: entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; @@ -1244,7 +1255,7 @@ static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func) if (array->nent >= array->maxnent) return -E2BIG; - array->nent += cpuid_func_emulated(&array->entries[array->nent], func); + array->nent += cpuid_func_emulated(&array->entries[array->nent], func, false); return 0; } |