diff -uNrp libvirt.orig/src/xend_internal.c libvirt/src/xend_internal.c
--- libvirt.orig/src/xend_internal.c	2009-02-14 03:23:23.000000000 +0900
+++ libvirt/src/xend_internal.c	2009-03-09 12:28:48.000000000 +0900
@@ -5566,7 +5566,11 @@ virDomainXMLDevID(virDomainPtr domain,
     char *xref;
 
     if (dev->type == VIR_DOMAIN_DEVICE_DISK) {
-        strcpy(class, "vbd");
+        if (!(strcmp(dev->data.disk->driverName, "tap"))) {
+            strcpy(class, "tap");
+        } else {
+            strcpy(class, "vbd");
+        }
         if (dev->data.disk->dst == NULL)
             return -1;
         xenUnifiedLock(priv);