diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h
index cd69391..fbb5883 100644
--- a/include/xen/interface/physdev.h
+++ b/include/xen/interface/physdev.h
@@ -121,6 +121,12 @@
 	} u;
 };
 
+#define PHYSDEVOP_get_nr_pirqs    22
+struct physdev_nr_pirqs {
+    /* OUT */
+    uint32_t nr_pirqs;
+};
+
 /*
  * Notify that some PIRQ-bound event channels have been unmasked.
  * ** This command is obsolete since interface version 0x00030202 and is **