diff --git a/tools/python/xen/xend/XendDomainInfo.py b/tools/python/xen/xend/XendDomainInfo.py
index e9d3e7e..36dc599 100644
--- a/tools/python/xen/xend/XendDomainInfo.py
+++ b/tools/python/xen/xend/XendDomainInfo.py
@@ -1167,7 +1167,7 @@ class XendDomainInfo:
         @param dev_config: device configuration
         @type  dev_config: SXP object (parsed config)
         @param devid:      device id
-        @type  devid:      int
+        @type  devid:      str
         @return: Returns True if successfully updated device
         @rtype: boolean
         """
@@ -1193,24 +1193,24 @@ class XendDomainInfo:
 
         dev_control = self.getDeviceController(dev_class)
         if devid is None:
-            dev = dev_config.get('dev', '')
-            if not dev:
+            devid = dev_config.get('dev', '')
+            if not devid:
                 raise VmError('Block device must have virtual details specified')
-            if 'ioemu:' in dev:
-                (_, dev) = dev.split(':', 1)
+            if 'ioemu:' in devid:
+                (_, devid) = devid.split(':', 1)
             try:
-                (dev, _) = dev.split(':', 1)  # Remove ":disk" or ":cdrom"
+                (devid, _) = devid.split(':', 1)  # Remove ":disk" or ":cdrom"
             except ValueError:
                 pass
-            devid = dev_control.convertToDeviceNumber(dev)
-        dev_info = self._getDeviceInfo_vbd(devid)
+        dev = dev_control.convertToDeviceNumber(devid)
+        dev_info = self._getDeviceInfo_vbd(dev)
         if dev_info is None:
             raise VmError("Device %s not connected" % devid)
         dev_uuid = sxp.child_value(dev_info, 'uuid')
 
         if self.domid is not None:
             # use DevController.reconfigureDevice to change device config
-            dev_control.reconfigureDevice(devid, dev_config)
+            dev_control.reconfigureDevice(dev, dev_config)
         else:
             (_, new_b, new_f) = dev_control.getDeviceDetails(dev_config)
             if (new_f['device-type'] == 'cdrom' and
@@ -1220,7 +1220,7 @@ class XendDomainInfo:
                 pass
             else:
                 raise VmError('Refusing to reconfigure device %s:%d to %s' %
-                              (dev_class, devid, dev_config))
+                              (dev_class, dev, dev_config))
 
         # update XendConfig with new device info
         self.info.device_update(dev_uuid, dev_sxp)