Description of problem:
Trying hot-plug cpu fails with the following exception:
Thread-5131::DEBUG::2014-09-03 16:55:56,825::__init__::467::jsonrpc.JsonRpcServer::(_serveRequest) Calling 'VM.setNumberOfCpus' in bridge with {u'numberOfCpus': u'1', u'vmID': u'e3dca780-cf24-47b9-a803-62ac086b7b10'}
Thread-5131::ERROR::2014-09-03 16:55:56,826::__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 264, in _dynamicMethod
    raise InvalidCall(fn, methodArgs, e)
InvalidCall: Attempt to call function: <bound method VM.setNumberOfCpus of <API.VM object at 0x7f54e0a27c90>> with arguments: (u'1',) error: setNumberOfCpus() takes exactly 3 arguments (2 given)


i tried without json and it works


 {'kernel': {'buildtime': 1384114794.0,
	                        'release': '431.el6.x86_64',
	                        'version': '2.6.32'},
	             'libvirt': {'buildtime': 1406015335,
	                         'release': '29.el6_5.11',
	                         'version': '0.10.2'},
	             'mom': {'buildtime': 1403794344, 'release': '2.el6', 'version': '0.4.1'},
	             'qemu-img': {'buildtime': 1408575896,
	                          'release': '2.415.el6_5.14',
	                          'version': '0.12.1.2'},
	             'qemu-kvm': {'buildtime': 1408575896,
	                          'release': '2.415.el6_5.14',
	                          'version': '0.12.1.2'},
	             'spice-server': {'buildtime': 1401730350,
	                              'release': '6.el6_5.2',
	                              'version': '0.12.4'},
	             'vdsm': {'buildtime': 1408610413,
	                      'release': '1.gite8cba75.el6',
	                      'version': '4.16.2'}}