[libvirt-users] question about libvirt network Xml

Hi, I’m an openstack developer trying to use Assignment from a pool of SRIOV VFs in a libvirt <network> definition from this link http://wiki.libvirt.org/page/Networking My question is is it possible for nova (the openstack compute) to know which VF out of the pool will be allocated to a VM before it invokes libvirt to launch it? Thanks In advance, Robert