Index: sys/xen/xen_intr.h
===================================================================
--- sys/xen/xen_intr.h
+++ sys/xen/xen_intr.h
@@ -38,7 +38,7 @@
 /** Registered Xen interrupt callback handle. */
 typedef void * xen_intr_handle_t;
 
-void xen_intr_handle_upcall(struct trapframe *trap_frame);
+driver_filter_t xen_intr_handle_upcall;
 
 /**
  * Associate an already allocated local event channel port an interrupt
Index: sys/xen/xen_intr.c
===================================================================
--- sys/xen/xen_intr.c
+++ sys/xen/xen_intr.c
@@ -491,9 +491,11 @@
  * 
  * \param trap_frame  The trap frame context for the current interrupt.
  */
-void
-xen_intr_handle_upcall(struct trapframe *trap_frame)
+int
+xen_intr_handle_upcall(void *_trap_frame)
 {
+	struct trapframe *trap_frame = _trap_frame;
+
 	u_int l1i, l2i, port, cpu;
 	u_long masked_l1, masked_l2;
 	struct xenisrc *isrc;
@@ -594,10 +596,14 @@
 		}
 	}
 
+#if defined(__amd64__) || defined(__i386__)
 	if (xen_evtchn_needs_ack)
 		lapic_eoi();
+#endif
 
 	critical_exit();
+
+	return (FILTER_HANDLED);
 }
 
 static int