'Get vcpu usage number of physical computer.
:returns: The total number of vcpu(s) that are currently being used.'

def _get_vcpu_used(self):

    total = 0
    for guest in self._host.list_guests():
        try:
            vcpus = guest.get_vcpus_info()
            total += len(list(vcpus))
        except libvirt.libvirtError:
            total += 1
        greenthread.sleep(0)
    return total
