KVM: VMX: support MSR_IA32_ARCH_CAPABILITIES as a feature MSR

This lets userspace read the MSR_IA32_ARCH_CAPABILITIES and check that all
requested features are available on the host.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 71e7cda..b91c1e1 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1092,6 +1092,7 @@ static u32 msr_based_features[] = {
 
        MSR_F10H_DECFG,
        MSR_IA32_UCODE_REV,
+       MSR_IA32_ARCH_CAPABILITIES,
 };
 
 static unsigned int num_msr_based_features;
@@ -1100,7 +1101,8 @@ static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
 {
        switch (msr->index) {
        case MSR_IA32_UCODE_REV:
-               rdmsrl(msr->index, msr->data);
+       case MSR_IA32_ARCH_CAPABILITIES:
+               rdmsrl_safe(msr->index, &msr->data);
                break;
        default:
                if (kvm_x86_ops->get_msr_feature(msr))