xm block-create doesn't work. It seems like this command hasn't even

been tested (perhaps since the un-Twisting?).  This particular problem 
was that one function was being called with self instead of the right 
argument and another function's return value was being used when it 
didn't actually return anything.

This patch also improves the error handling a bit by making sure we 
don't thrown an exception on a log statement with a None value.  In 
general, one should always use the % formatter instead of concatination 
for strings in Python (even though this is not what this patch does).

Signed-off-by: Anthony Liguori

tools/python/xen/xend/XendDomainInfo.py

@@ -138,7 +138,7 @@ def dom_get(dom):
     if domlist and dom == domlist[0]['dom']:
         return domlist[0]
     return None
-    
+
 class XendDomainInfo:
     """Virtual machine object."""
 
@@ -754,7 +754,7 @@ class XendDomainInfo:
         @param dev_config: device configuration
         """
         dev_type = sxp.name(dev_config)
-        dev = self.createDevice(self, dev_config, change=True)
+        dev = self.createDevice(dev_type, dev_config, change=True)
         self.config.append(['device', dev.getConfig()])
         return dev.sxpr()
 

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

@@ -142,7 +142,7 @@ class DevControllerTable:
     def createDevController(self, type, vm, recreate=False):
         cls = self.getDevControllerClass(type)
         if not cls:
-            raise XendError("unknown device type: " + type)
+            raise XendError("unknown device type: " + str(type))
         return cls.createDevController(vm, recreate=recreate)
 
 def getDevControllerTable():
@@ -283,6 +283,8 @@ class DevController:
         dev.attach(recreate=recreate, change=change)
         dev.exportToDB()
 
+        return dev
+
     def configureDevice(self, id, config, change=False):
         """Reconfigure an existing device.
         May be defined in subclass."""
@@ -325,7 +327,7 @@ class DevController:
     def getDevice(self, id, error=False):
         dev = self.devices.get(id)
         if error and not dev:
-            raise XendError("invalid device id: " + id)
+            raise XendError("invalid device id: " + str(id))
         return dev
 
     def getDeviceIds(self):