Created attachment 942245 [details]
engine and vdsm logs

Description of problem:
hotplug/hotunplug NIC to VM fail with error:

Thread-9547::DEBUG::2014-09-28 13:56:17,249::vm::3684::vm.Vm::(hotunplugNic) vmId=`55b9e89a-d5b8-4984-8ab7-72009aba9edb`::Hotunplug NIC xml: <interface type="bridge">
        <address bus="0x00" domain="0x0000" function="0x0" slot="0x09" type="pci"/>
        <mac address="00:1a:4a:16:88:52"/>
        <model type="virtio"/>
        <source bridge="sw163"/>
        <filterref filter="vdsm-no-mac-spoofing"/>
        <link state="up"/>
        <bandwidth/>
</interface>

GuestMonitor-Global_vm_1::DEBUG::2014-09-28 13:56:17,293::vm::486::vm.Vm::(_getUserCpuTuneInfo) vmId=`8e64da17-1d6b-460f-bd35-5710eb0160a2`::Domain Metadata is not set
GuestMonitor-Global_vm_1::DEBUG::2014-09-28 13:56:17,294::vm::486::vm.Vm::(_getUserCpuTuneInfo) vmId=`8e64da17-1d6b-460f-bd35-5710eb0160a2`::Domain Metadata is not set
GuestMonitor-Global_vm_1::DEBUG::2014-09-28 13:56:17,295::vm::486::vm.Vm::(_getUserCpuTuneInfo) vmId=`8e64da17-1d6b-460f-bd35-5710eb0160a2`::Domain Metadata is not set
Thread-9547::ERROR::2014-09-28 13:56:17,530::__init__::491::jsonrpc.JsonRpcServer::(_serveRequest) Internal server error
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/yajsonrpc/__init__.py", line 486, in _serveRequest
    res = method(**params)
  File "/usr/share/vdsm/rpc/Bridge.py", line 286, in _dynamicMethod
    ret = retfield(result)
  File "/usr/share/vdsm/rpc/Bridge.py", line 236, in _fixupRet
    continue
  File "/usr/share/vdsm/rpc/Bridge.py", line 216, in _typeFixup
    logging.warn("Fixing up type %s", symTypeName)
TypeError: argument of type 'NoneType' is not iterable 

Version-Release number of selected component (if applicable):
vdsm-4.16.5-2.el6ev.x86_64

How reproducible:
100%

Steps to Reproduce:
1. hotplug/hotunplug NIC to/from VM


Actual results:
hotplug/hotunplug NIC fail


Additional info:
When running with XML-RPC I don't have this issue