intel_iommu: set IR bit for ECAP register

Enable IR in IOMMU Extended Capability register.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index b648e69..5b98a11 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -176,6 +176,8 @@
 /* (offset >> 4) << 8 */
 #define VTD_ECAP_IRO                (DMAR_IOTLB_REG_OFFSET << 4)
 #define VTD_ECAP_QI                 (1ULL << 1)
+/* Interrupt Remapping support */
+#define VTD_ECAP_IR                 (1ULL << 3)
 
 /* CAP_REG */
 /* (offset >> 4) << 24 */