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>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c61ec9c..4db0c8a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3269,6 +3269,7 @@
 int emulate_clts(struct kvm_vcpu *vcpu)
 {
 	kvm_x86_ops->set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~X86_CR0_TS));
+	kvm_x86_ops->fpu_activate(vcpu);
 	return X86EMUL_CONTINUE;
 }