libvirt: Add some testcases for virsh cpu-compare

Li Yang (2):
  libvirt: Add some test cases for virsh cpu-compare
  virt: Add set_cpu_mode() function for virsh cpu-compare

 libvirt/tests/cfg/virsh_cpu_compare.cfg |   40 ++++++++++++++---
 libvirt/tests/virsh_cpu_compare.py      |   73 ++++++++++++++++++++++++++-----
 virttest/libvirt_xml/vm_xml.py          |   28 ++++++++++++
 3 files changed, 122 insertions(+), 19 deletions(-)