xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers

Impact: new Xen-internal API

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/include/xen/events.h b/include/xen/events.h
index 00f53dd..bd03b1e 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -23,6 +23,12 @@
 			   unsigned long irqflags,
 			   const char *devname,
 			   void *dev_id);
+int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
+					  unsigned int remote_port,
+					  irq_handler_t handler,
+					  unsigned long irqflags,
+					  const char *devname,
+					  void *dev_id);
 
 /*
  * Common unbind function for all event sources. Takes IRQ to unbind from.