KVM: x86: Fix xsave cpuid exposing bug

[deliverable/linux.git] / arch / x86 / kvm / x86.c

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 151e8c3b1f4a3f3e41053c2bea4f91093e7644c2..3da8df8ea63cd34c0f09434a75e7bce96b12f73e 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -595,13 +595,13 @@ static void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu)
 
 int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
 {
-       u64 xcr0;
+       u64 xcr0 = xcr;
+       u64 old_xcr0 = vcpu->arch.xcr0;
        u64 valid_bits;
 
        /* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now  */
        if (index != XCR_XFEATURE_ENABLED_MASK)
                return 1;
-       xcr0 = xcr;
        if (!(xcr0 & XSTATE_FP))
                return 1;
        if ((xcr0 & XSTATE_YMM) && !(xcr0 & XSTATE_SSE))
@@ -618,6 +618,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
 
        kvm_put_guest_xcr0(vcpu);
        vcpu->arch.xcr0 = xcr0;
+
+       if ((xcr0 ^ old_xcr0) & XSTATE_EXTEND_MASK)
+               kvm_update_cpuid(vcpu);
        return 0;
 }