Adding uplink_status_propagation option

Add charm option uplink-status-propagation, which for releases >= stein
will add the ml2 plugin uplink_status_propagation, that enabled ports to
have the propagate_uplink_status attribute to allow instance VF to see the PF
link state change for SR-IOV ports.

Change-Id: I4f1ace630c74363057b0bbdbc759c482125ad015
Closes-Bug: 1949491

config.yaml

@@ -800,3 +800,10 @@ options:
     description: |
       If True, on Ussuri or later, igmp snooping will be set on OVS and OVN
       control plane will learn about multicast traffic going on in the cluster.
+  uplink-status-propagation:
+    type: boolean
+    default: False
+    description: |
+      If True, on Stein or later attribute 'propagate_uplink_status' will be
+      available to port. This attribute can be implemented for VF port to
+      indicate if the VF link state should follow the state of the PF.

hooks/neutron_api_context.py

@@ -52,6 +52,7 @@ EXTENSION_DRIVER_PORT_SECURITY = 'port_security'
 EXTENSION_DRIVER_DNS = 'dns'
 EXTENSION_DRIVER_DNS_DOMAIN_PORTS = 'dns_domain_ports'
 EXTENSION_DRIVER_QOS = 'qos'
+EXTENSION_DRIVER_UPLINK_STATUS_PROP = 'uplink_status_propagation'
 
 ETC_NEUTRON = '/etc/neutron'
 
@@ -590,6 +591,9 @@ class NeutronCCContext(context.NeutronContext):
         if is_qos_requested_and_valid():
             extension_drivers.append(EXTENSION_DRIVER_QOS)
 
+        if config('uplink-status-propagation') and cmp_release >= 'stein':
+            extension_drivers.append(EXTENSION_DRIVER_UPLINK_STATUS_PROP)
+
         if extension_drivers:
             ctxt['extension_drivers'] = ','.join(extension_drivers)