code: def setup_logical_port_connectivity(self, context, port_db,
                                          hosting_device_id):
          
          hosting_port = port_db.hosting_info.hosting_port
          if hosting_port:
              try:
                  self._dev_mgr.svc_vm_mgr.interface_attach(hosting_device_id,
                                                            hosting_port.id)
                  LOG.debug("Setup logical port completed for port:%s",
                            port_db.id)
              except nova_exc.Conflict as e:
                  # VM is still in vm_state building
                  LOG.debug("Failed to attach interface - spawn thread "
                            "error %(error)s", {'error': str(e)})
                  self._gt_pool.spawn_n(self._attach_hosting_port,
                                        hosting_device_id, hosting_port.id)
              except Exception as e:
                  LOG.error("Failed to attach interface mapped to port:"
                            "%(p_id)s on hosting device:%(hd_id)s due to "
                            "error %(error)s", {'p_id': hosting_port.id,
                                                'hd_id': hosting_device_id,
                                                'error': str(e)})
docs: Establishes connectivity for a logical port.
  
          This is done by hot plugging the interface(VIF) corresponding to the
          port from the VM.