VLAN aware VM (QinQ) is not getting spawned in OVS+DPDK setup

Issue

• Why launch of VLAN aware instance is getting failed with following message?

2017-01-05 02:02:25.126 40178 ERROR nova.network.linux_net [req-b4eebb81-25a2-4060-9d08-69e3a7c9b6f0 30cf353c5c094ad1b6060d55f7d7feff 47e925e032b14635ac2e656811b5c28b - - -] Unable to execute ['ovs-vsctl', '--timeout=120', '--', '--if-exists', 'del-port', u'vhu1b7b2661-d0', '--', 'add-port', u'tbr-3c465abf-e', u'vhu1b7b2661-d0', '--', 'set', 'Interface', u'vhu1b7b2661-d0', u'external-ids:iface-id=1b7b2661-d074-4356-9c57-3b9a29667d36', 'external-ids:iface-status=active', u'external-ids:attached-mac=xx:xx:xx:66:ae', 'external-ids:vm-uuid=9c11637a-8d18-401c-a9c4-018765110d90', 'type=dpdkvhostuser']. Exception: Unexpected error while running command.
Command: sudo nova-rootwrap /etc/nova/rootwrap.conf ovs-vsctl --timeout=120 -- --if-exists del-port vhu1b7b2661-d0 -- add-port tbr-3c465abf-e vhu1b7b2661-d0 -- set Interface vhu1b7b2661-d0 external-ids:iface-id=1b7b2661-d074-4356-9c57-3b9a29667d36 external-ids:iface-status=active external-ids:attached-mac=xx:xx:xx:66:ae external-ids:vm-uuid=9c11637a-8d18-401c-a9c4-018765110d90 type=dpdkvhostuser
Exit code: 1
Stdout: u''
Stderr: u'ovs-vsctl: no bridge named tbr-3c465abf-e\n'
2017-01-05 02:02:25.127 40178 ERROR nova.compute.manager [req-b4eebb81-25a2-4060-9d08-69e3a7c9b6f0 30cf353c5c094ad1b6060d55f7d7feff 47e925e032b14635ac2e656811b5c28b - - -] [instance: 9c11637a-8d18-401c-a9c4-018765110d90] Instance failed to spawn

2017-01-05 02:02:25.127 40178 ERROR nova.compute.manager [instance: 9c11637a-8d18-401c-a9c4-018765110d90] OvsConfigurationFailure: OVS configuration failed with: Unexpected error while running command.
2017-01-05 02:02:25.127 40178 ERROR nova.compute.manager [instance: 9c11637a-8d18-401c-a9c4-018765110d90] Command: sudo nova-rootwrap /etc/nova/rootwrap.conf ovs-vsctl --timeout=120 -- --if-exists del-port vhu1b7b2661-d0 -- add-port tbr-3c465abf-e vhu1b7b2661-d0 -- set Interface vhu1b7b2661-d0 external-ids:iface-id=1b7b2661-d074-4356-9c57-3b9a29667d36 external-ids:iface-status=active external-ids:attached-mac=xx:xx:xx:66:ae external-ids:vm-uuid=9c11637a-8d18-401c-a9c4-018765110d90 type=dpdkvhostuser
2017-01-05 02:02:25.127 40178 ERROR nova.compute.manager [instance: 9c11637a-8d18-401c-a9c4-018765110d90] Exit code: 1
2017-01-05 02:02:25.127 40178 ERROR nova.compute.manager [instance: 9c11637a-8d18-401c-a9c4-018765110d90] Stdout: u''
2017-01-05 02:02:25.127 40178 ERROR nova.compute.manager [instance: 9c11637a-8d18-401c-a9c4-018765110d90] Stderr: u'ovs-vsctl: no bridge named tbr-3c465abf-e\n'.
2017-01-05 02:02:25.127 40178 ERROR nova.compute.manager [instance: 9c11637a-8d18-401c-a9c4-018765110d90] 
2017-01-05 02:02:25.127 40178 INFO nova.compute.manager [req-b4eebb81-25a2-4060-9d08-69e3a7c9b6f0 30cf353c5c094ad1b6060d55f7d7feff 47e925e032b14635ac2e656811b5c28b - - -] [instance: 9c11637a-8d18-401c-a9c4-018765110d90] Terminating instance