KVM: Activate fpu on clts

Assume that if the guest executes clts, it knows what it's doing, and load the
guest fpu to prevent an #NM exception.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index a281368c3b96..800208a60a51 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1259,12 +1259,17 @@ static int ud_interception(struct vcpu_svm *svm)
         return 1;
 }
 
-static int nm_interception(struct vcpu_svm *svm)
+static void svm_fpu_activate(struct kvm_vcpu *vcpu)
 {
+        struct vcpu_svm *svm = to_svm(vcpu);
         svm->vmcb->control.intercept_exceptions &= ~(1 << NM_VECTOR);
         svm->vcpu.fpu_active = 1;
         update_cr0_intercept(svm);
+}
 
+static int nm_interception(struct vcpu_svm *svm)
+{
+        svm_fpu_activate(&svm->vcpu);
         return 1;
 }
 
@@ -2977,6 +2982,7 @@ static struct kvm_x86_ops svm_x86_ops = {
         .cache_reg = svm_cache_reg,
         .get_rflags = svm_get_rflags,
         .set_rflags = svm_set_rflags,
+        .fpu_activate = svm_fpu_activate,
         .fpu_deactivate = svm_fpu_deactivate,
 
         .tlb_flush = svm_flush_tlb,