Created attachment 1105288 [details]
vdsm log

Description of problem:
Start vm with "Pass-Through Host CPU" enabled failed with traceback under vdsm log:
Thread-22434::ERROR::2015-12-13 05:03:58,956::vm::758::virt.vm::(_startUnderlyingVm) vmId=`3f3cd31f-b2de-4341-b36b-6b63898935f0`::The vm start process failed
Traceback (most recent call last):
  File "/usr/share/vdsm/virt/vm.py", line 702, in _startUnderlyingVm
    self._run()
  File "/usr/share/vdsm/virt/vm.py", line 1889, in _run
    self._connection.createXML(domxml, flags),
  File "/usr/lib/python2.7/site-packages/vdsm/libvirtconnection.py", line 124, in wrapper
    ret = f(*args, **kwargs)
  File "/usr/lib64/python2.7/site-packages/libvirt.py", line 3611, in createXML
    if ret is None:raise libvirtError('virDomainCreateXML() failed', conn=self)
libvirtError: internal error: Unknown CPU model hostPassthrough


Version-Release number of selected component (if applicable):
vdsm-4.17.13-1.el7ev.noarch

How reproducible:
Always

Steps to Reproduce:
1. Create vm and pin it to host
2. Enable "Pass-Through Host CPU" option on vm
3. Start vm

Actual results:
vm failed to start with above error

Expected results:
vm succeed to start and inherit cpu flags from host cpu

Additional info:
looks like instead of mode we send hostPassthrough to cpu model
  <cpu>
                <model>hostPassthrough</model>
                <topology cores="1" sockets="1" threads="1"/>
        </cpu>