OVS: fix an issue on xenserver

ovs bridges are deleted by xenserver/ovs automatically
```
[root@ref-trl-1797-x-M7-wei-zhou-xs2 ~]# grep -r xapi7 /var/log/ |grep del-br
/var/log/xensource.log:Sep 15 07:13:44 ref-trl-1797-x-M7-wei-zhou-xs2 xcp-networkd: [ info|localhost|611 |org.xen.xapi.xenops.classic events D:4a3d931cd89f|network_utils] /usr/bin/ovs-vsctl --timeout=20 -- --if-exists del-br xapi7
/var/log/daemon.log:Sep 15 07:13:45 ref-trl-1797-x-M7-wei-zhou-xs2 ovs-vsctl: ovs|00001|vsctl|INFO|Called as /usr/bin/ovs-vsctl --timeout=20 -- --if-exists del-br xapi7
```

which results that xe network exists but bridge does not exist, and operation stuck for 20 minutes at
```
2021-09-15 16:06:56    DEBUG [root] #### VMOPS enter  create_tunnel ####
2021-09-15 16:06:56    DEBUG [root] Creating tunnel from host 2 to host 1 with GRE key 2116
2021-09-15 16:06:56    DEBUG [root] Executing:['/usr/bin/ovs-vsctl', '--timeout=0', 'wait-until', 'bridge', 'xapi7', '--', 'get', 'bridge', 'xapi7', 'name']
2021-09-15 16:26:56    DEBUG [root] bridge xapi7 for creating tunnel - VERIFIED
2021-09-15 16:26:56    DEBUG [root] Executing:['/usr/bin/ovs-vsctl', 'add-port', 'xapi7', 't2116-2-1', '--', 'set', 'interface', 't2116-2-1', 'type=gre', 'options:key=2116', 'options:remote_ip=10.0.34.230']
```

Author: weizhouapache

plugins/hypervisors/xenserver/src/main/java/com/cloud/hypervisor/xenserver/resource/CitrixResourceBase.java

@@ -884,33 +884,18 @@ public synchronized Network configureTunnelNetwork(final Connection conn, final
             // Invoke plugin to setup the bridge which will be used by this
             // network
             final String bridge = nw.getBridge(conn);
-            final Map<String, String> nwOtherConfig = nw.getOtherConfig(conn);
-            final String configuredHosts = nwOtherConfig.get("ovs-host-setup");
-            boolean configured = false;
-            if (configuredHosts != null) {
-                final String hostIdsStr[] = configuredHosts.split(",");
-                for (final String hostIdStr : hostIdsStr) {
-                    if (hostIdStr.equals(((Long)hostId).toString())) {
-                        configured = true;
-                        break;
-                    }
-                }
+            String result;
+            if (bridgeName.startsWith("OVS-DR-VPC-Bridge")) {
+                result = callHostPlugin(conn, "ovstunnel", "setup_ovs_bridge_for_distributed_routing", "bridge", bridge, "key", bridgeName, "xs_nw_uuid", nw.getUuid(conn), "cs_host_id",
+                        ((Long)hostId).toString());
+            } else {
+                result = callHostPlugin(conn, "ovstunnel", "setup_ovs_bridge", "bridge", bridge, "key", bridgeName, "xs_nw_uuid", nw.getUuid(conn), "cs_host_id", ((Long)hostId).toString());
             }
 
-            if (!configured) {
-                String result;
-                if (bridgeName.startsWith("OVS-DR-VPC-Bridge")) {
-                    result = callHostPlugin(conn, "ovstunnel", "setup_ovs_bridge_for_distributed_routing", "bridge", bridge, "key", bridgeName, "xs_nw_uuid", nw.getUuid(conn), "cs_host_id",
-                            ((Long)hostId).toString());
-                } else {
-                    result = callHostPlugin(conn, "ovstunnel", "setup_ovs_bridge", "bridge", bridge, "key", bridgeName, "xs_nw_uuid", nw.getUuid(conn), "cs_host_id", ((Long)hostId).toString());
-                }
-
-                // Note down the fact that the ovs bridge has been setup
-                final String[] res = result.split(":");
-                if (res.length != 2 || !res[0].equalsIgnoreCase("SUCCESS")) {
-                    throw new CloudRuntimeException("Unable to pre-configure OVS bridge " + bridge);
-                }
+            // Note down the fact that the ovs bridge has been setup
+            final String[] res = result.split(":");
+            if (res.length != 2 || !res[0].equalsIgnoreCase("SUCCESS")) {
+                throw new CloudRuntimeException("Unable to pre-configure OVS bridge " + bridge);
             }
             return nw;
         } catch (final Exception e) {

scripts/vm/hypervisor/xenserver/ovstunnel

@@ -106,9 +106,16 @@ def setup_ovs_bridge(session, args):
                                 "uuid=%s" % xs_nw_uuid,
                                 "param-name=other-config",
                                 "param-key=ovs-host-setup"])
-        conf_hosts = cs_host_id + (conf_hosts and ',%s' % conf_hosts or '')
-        lib.do_cmd([lib.XE_PATH, "network-param-set", "uuid=%s" % xs_nw_uuid,
-                   "other-config:ovs-host-setup=%s" % conf_hosts])
+        host_found = False
+        if conf_hosts:
+            setup_hosts = conf_hosts.split(",")
+            for host in setup_hosts:
+                if host == cs_host_id:
+                    host_found = True
+        if not host_found:
+            conf_hosts = cs_host_id + (conf_hosts and ',%s' % conf_hosts or '')
+            lib.do_cmd([lib.XE_PATH, "network-param-set", "uuid=%s" % xs_nw_uuid,
+                       "other-config:ovs-host-setup=%s" % conf_hosts])
 
         # BLOCK IPv6 - Flow spec changes with ovs version
         # Temporarily no need BLOCK IPv6
@@ -161,9 +168,16 @@ def setup_ovs_bridge_for_distributed_routing(session, args):
                                 "uuid=%s" % xs_nw_uuid,
                                 "param-name=other-config",
                                 "param-key=ovs-host-setup"])
-        conf_hosts = cs_host_id + (conf_hosts and ',%s' % conf_hosts or '')
-        lib.do_cmd([lib.XE_PATH, "network-param-set", "uuid=%s" % xs_nw_uuid,
-                   "other-config:ovs-host-setup=%s" % conf_hosts])
+        host_found = False
+        if conf_hosts:
+            setup_hosts = conf_hosts.split(",")
+            for host in setup_hosts:
+                if host == cs_host_id:
+                    host_found = True
+        if not host_found:
+            conf_hosts = cs_host_id + (conf_hosts and ',%s' % conf_hosts or '')
+            lib.do_cmd([lib.XE_PATH, "network-param-set", "uuid=%s" % xs_nw_uuid,
+                       "other-config:ovs-host-setup=%s" % conf_hosts])
 
         # first clear the default rule (rule for 'NORMAL' processing which makes a bridge simple L2 learn & flood switch)
         lib.del_flows(bridge, table=0)