Comment 8 for bug 1607714

Nevermind, it's the compute manager in nova that's telling neutron that the port is no longer bound:

https://github.com/openstack/nova/blob/fdf3328107e53f1c5578c2e4dfbad78d832b01c6/nova/compute/manager.py#L4990

We first call the virt driver to detach the interface (which is async) and then update the port telling neutron that the device_id is '', which is what tempest is waiting for.

So if we add a poll / retry in the libvirt guest module for the detach, we can delay the port update which tempest is waiting for and we should be good.