Xend forgets to write the domain's VDI UUID into the domain state file

once the domain is started (before it's there). Once xend is restarted
it will not know the association between the VBD and VDI anymore due
to the missing UUID. This patch fixes this.

Signed-off-by: Stefan Berger <stefanb@us.ibm.com>

tools/python/xen/xend/XendConfig.py

@@ -991,6 +991,7 @@ class XendConfig(dict):
                                     dev_type, dev_cfg = self['devices'][dev_uuid]
                                     is_bootable = dev_cfg.get('bootable', 0)
                                     config.append(['bootable', int(is_bootable)])
+                                    config.append(['VDI'], dev_cfg.get('VDI', ''))
 
                                 sxpr.append(['device', config])