Index: sys/dev/xen/bus/xen_intr.c
===================================================================
--- sys/dev/xen/bus/xen_intr.c
+++ sys/dev/xen/bus/xen_intr.c
@@ -433,7 +433,8 @@
 	*isrcp = NULL;
 	if (port_handlep == NULL) {
 		printf("%s: %s: Bad event handle\n", intr_owner, __func__);
-		return (EINVAL);
+		error = EINVAL;
+		goto failearly;
 	}
 	*port_handlep = NULL;
 
@@ -443,8 +444,10 @@
 	    params->xi_type));
 
 	isrc = xen_intr_alloc_isrc(params);
-	if (isrc == NULL)
-		return (ENOSPC);
+	if (isrc == NULL) {
+		error = ENOSPC;
+		goto failearly;
+	}
 	refcount_init(&isrc->xi_refcount, 1);
 #ifdef SMP
 	cpu = isrc->xi_cpu;
@@ -502,6 +505,15 @@
 	/* Assign the opaque handler */
 	*port_handlep = xen_intr_handle_from_isrc(isrc);
 	return (0);
+
+failearly:
+	if (params->xi_close) {
+		evtchn_close_t close = { .port = params->xi_port };
+		if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close))
+			panic("EVTCHNOP_close failed");
+	}
+
+	return (error);
 }
 
 /**