KVM: x86: fix CR8 handling

The handling of CR8 writes in KVM is currently somewhat cumbersome.
This patch makes it look like the other CR register handlers
and fixes a possible issue in VMX, where the RIP would be incremented
despite an injected #GP.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c195260..8e87bae 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3185,8 +3185,8 @@
 		case 8: {
 				u8 cr8_prev = kvm_get_cr8(vcpu);
 				u8 cr8 = kvm_register_read(vcpu, reg);
-				kvm_set_cr8(vcpu, cr8);
-				skip_emulated_instruction(vcpu);
+				err = kvm_set_cr8(vcpu, cr8);
+				complete_insn_gp(vcpu, err);
 				if (irqchip_in_kernel(vcpu->kvm))
 					return 1;
 				if (cr8_prev <= cr8)