Description of problem:
During FFU new vms with SRIOV ports cannot be created.

Controllers in 0sp16.1 cannot configure new ports in computes Osp13 due to this feature:

https://bugs.launchpad.net/neutron/+bug/1580880


https://github.com/openstack/neutron/blob/master/neutron/plugins/ml2/drivers/mech_sriov/agent/sriov_nic_agent.py#L337

...

    def treat_devices_added_updated(self, devices_info):
        try:
            macs_list = set([device_info[0] for device_info in devices_info])
            devices_details_list = self.plugin_rpc.get_devices_details_list(
                self.context, macs_list, self.agent_id, self.conf.host)
        except Exception as e:
            LOG.debug("Unable to get port details for devices "
                      "with MAC addresses %(devices)s: %(e)s",
                      {'devices': macs_list, 'e': e})
            # resync is needed
            return True

        devices_up = set()
        devices_down = set()
        resync = False
        for device_details in devices_details_list:
            device = device_details['device']
            LOG.debug("Port with MAC address %s is added", device)

            if 'port_id' in device_details:
                LOG.info("Port %(device)s updated. Details: %(details)s",
                         {'device': device, 'details': device_details})
                port_id = device_details['port_id']
                profile = device_details['profile']
                spoofcheck = device_details.get('port_security_enabled', True)
                if self.treat_device(
                        device,
                        profile.get('pci_slot'),
                        device_details['admin_state_up'],
                        spoofcheck,
                        device_details['propagate_uplink_status']):
                    if device_details['admin_state_up']:
                        devices_up.add(device)
                    else:
                        devices_down.add(device)
                else:
                    resync = True
                self._update_network_ports(device_details['network_id'],
                                           port_id,
                                           (device, profile.get('pci_slot')))
                self.ext_manager.handle_port(self.context, device_details)


The function  _get_device_details has changed:

...

020-09-24 00:11:50.858 31268 INFO neutron.plugins.ml2.drivers.mech_sriov.agent.sriov_nic_agent [req-3f246188-d8f7-43b8-b731-9948e4d50557 - - - - -] Device with MAC 00:00:00:00:00:00 not defined on plugin



Version-Release number of selected component (if applicable):

(overcloud) [stack@undercloud-0 ~]$ cat core_puddle_version 
RHOS-16.1-RHEL-8-20200917.n.3(overcloud) [stack@undercloud-0 ~]$

How reproducible:

Execute FFu 13 --->16.1

And after first controller ffu is completed, try to create a vm.

Actual results:
Vm creation fails

Expected results:

Vm is created or document the limitation