Comment 6 for bug 1323204

A fix added to contrailvif driver. The root cause of the issue is that the tap device is deleted before the vhost-net could be freed up from libvirt. When libvirt initializes vhost-net, the corresponding tap device already exists, however, during deletion path, tap device is freed up first followed by attempted vhost-net deallocation by libvirt. This results in qemu core. It seems to be a known issue (a similar bug exists, https://bugzilla.redhat.com/show_bug.cgi?format=multiple&id=1004608). The fix is to defer the deletion of tap device from contrailvif driver to a later time so that libvirt could free up vhost-net.