x86/vvmx: don't enable interrupt window when using virt intr delivery

If virtual interrupt delivery is used to inject the interrupt to the
guest the interrupt window shouldn't be enabled, as the interrupt is
already injected using the GUEST_INTR_STATUS vmcs field.

Reported-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

xen/arch/x86/hvm/vmx/intr.c

@@ -209,7 +209,7 @@ static int nvmx_intr_intercept(struct vcpu *v, struct hvm_intack intack)
                 if ( unlikely(intack.source != hvm_intsrc_none) )
                     vmx_enable_intr_window(v, intack);
             }
-            else
+            else if ( !cpu_has_vmx_virtual_intr_delivery )
                 vmx_enable_intr_window(v, intack);
 
             return 1;