Hack around problem whereby VMX domains (using the ioemu device) now fail

because the new hotplug script error checking kicks in.

ioemu really ought to move out of blkif.py.

Signed-off-by: Ewan Mellor <ewan@xensource.com>

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

@@ -57,6 +57,8 @@ class DevController:
         @return The ID for the newly created device.
         """
         (devid, back, front) = self.getDeviceDetails(config)
+        if devid is None:
+            return 0
 
         self.writeDetails(config, devid, back, front)
 

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

@@ -43,7 +43,7 @@ class BlkifController(DevController):
         
         dev = sxp.child_value(config, 'dev')
         if re.match('^ioemu:', dev):
-            return (0,{},{})
+            return (None,{},{})
 
         devid = blkif.blkdev_name_to_number(dev)