Use ioemu block drivers through blktap.

Add support for a tap:ioemu pseudo driver. Devices using this driver
won't use tapdisk (containing the code duplication) any more, but will
connect to the qemu-dm of the domain. In this way no working
configuration should be broken right now as you can still choose to
use the tapdisk drivers.

Signed-off-by: Kevin Wolf <kwolf@suse.de>

tools/python/xen/xend/server/BlktapController.py

@@ -13,7 +13,9 @@ blktap_disk_types = [
     'vmdk',
     'ram',
     'qcow',
-    'qcow2'
+    'qcow2',
+
+    'ioemu'
     ]
 
 class BlktapController(BlkifController):