VMs fail to start or migrate, reporting "internal error missing IFLA_VF_INFO in netlink response" error

Issue

• Since upgrading to RHEL 6.7, VMs in a Cicso VMFEX environment will no longer start.

• VMs also fail to migrate to such a host.

• libvirtd reports internal error missing IFLA_VF_INFO in netlink response when trying to start a VM in a Cicso VMFEX environment.

• The vdsm logs contain the following error;

 Traceback (most recent call last):
  File "/usr/share/vdsm/virt/migration.py", line 246, in run
    self._startUnderlyingMigration(time.time())
  File "/usr/share/vdsm/virt/migration.py", line 335, in _startUnderlyingMigration
    None, maxBandwidth)
  File "/usr/share/vdsm/virt/vm.py", line 702, in f
    ret = attr(*args, **kwargs)
  File "/usr/lib/python2.6/site-packages/vdsm/libvirtconnection.py", line 111, in wrapper
    ret = f(*args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 1210, in migrateToURI2
    if ret == -1: raise libvirtError ('virDomainMigrateToURI2() failed', dom=self)
libvirtError: internal error missing IFLA_VF_INFO in netlink response