[ovs-dev,v5,1/2] northd: Make `vxlan_mode` a global variable.

diff --git a/northd/en-global-config.c b/northd/en-global-config.c
index 28c78a12c..873649a89 100644
--- a/northd/en-global-config.c
+++ b/northd/en-global-config.c
@@ -115,8 +115,8 @@  en_global_config_run(struct engine_node *node , void *data)
                      config_data->svc_monitor_mac);
     }
 
-    char *max_tunid = xasprintf("%d",
-        get_ovn_max_dp_key_local(sbrec_chassis_table));
+    init_vxlan_mode(sbrec_chassis_table);
+    char *max_tunid = xasprintf("%d", get_ovn_max_dp_key_local());
     smap_replace(options, "max_tunid", max_tunid);
     free(max_tunid);
 
diff --git a/northd/northd.c b/northd/northd.c
index 133cddb69..0e0ae24db 100644
--- a/northd/northd.c
+++ b/northd/northd.c
@@ -90,6 +90,10 @@  static bool use_ct_inv_match = true;
  */
 static bool default_acl_drop;
 
+/* If this option is 'true' northd will use limited 24-bit space for datapath
+ * and ports tunnel key allocation (12 bits for each instead of default 16). */
+static bool vxlan_mode;
+
 #define MAX_OVN_TAGS 4096
 
 
@@ -881,40 +885,40 @@  join_datapaths(const struct nbrec_logical_switch_table *nbrec_ls_table,
     }
 }
 
-static bool
-is_vxlan_mode(const struct sbrec_chassis_table *sbrec_chassis_table)
+void
+init_vxlan_mode(const struct sbrec_chassis_table *sbrec_chassis_table)
 {
     const struct sbrec_chassis *chassis;
     SBREC_CHASSIS_TABLE_FOR_EACH (chassis, sbrec_chassis_table) {
         for (int i = 0; i < chassis->n_encaps; i++) {
             if (!strcmp(chassis->encaps[i]->type, "vxlan")) {
-                return true;
+                vxlan_mode = true;
+                return;
             }
         }
     }
-    return false;
+    vxlan_mode = false;
 }
 
 uint32_t
-get_ovn_max_dp_key_local(const struct sbrec_chassis_table *sbrec_chassis_table)
+get_ovn_max_dp_key_local(void)
 {
-    if (is_vxlan_mode(sbrec_chassis_table)) {
-        /* OVN_MAX_DP_GLOBAL_NUM doesn't apply for vxlan mode. */
+    if (vxlan_mode) {
+        /* OVN_MAX_DP_GLOBAL_NUM doesn't apply for VXLAN mode. */
         return OVN_MAX_DP_VXLAN_KEY;
     }
     return OVN_MAX_DP_KEY - OVN_MAX_DP_GLOBAL_NUM;
 }
 
 static void
-ovn_datapath_allocate_key(const struct sbrec_chassis_table *sbrec_ch_table,
-                          struct hmap *datapaths, struct hmap *dp_tnlids,
+ovn_datapath_allocate_key(struct hmap *datapaths, struct hmap *dp_tnlids,
                           struct ovn_datapath *od, uint32_t *hint)
 {
     if (!od->tunnel_key) {
         od->tunnel_key = ovn_allocate_tnlid(dp_tnlids, "datapath",
-                                    OVN_MIN_DP_KEY_LOCAL,
-                                    get_ovn_max_dp_key_local(sbrec_ch_table),
-                                    hint);
+                                            OVN_MIN_DP_KEY_LOCAL,
+                                            get_ovn_max_dp_key_local(),
+                                            hint);
         if (!od->tunnel_key) {
             if (od->sb) {
                 sbrec_datapath_binding_delete(od->sb);
@@ -927,7 +931,6 @@  ovn_datapath_allocate_key(const struct sbrec_chassis_table *sbrec_ch_table,
 
 static void
 ovn_datapath_assign_requested_tnl_id(
-    const struct sbrec_chassis_table *sbrec_chassis_table,
     struct hmap *dp_tnlids, struct ovn_datapath *od)
 {
     const struct smap *other_config = (od->nbs
@@ -936,8 +939,7 @@  ovn_datapath_assign_requested_tnl_id(
     uint32_t tunnel_key = smap_get_int(other_config, "requested-tnl-key", 0);
     if (tunnel_key) {
         const char *interconn_ts = smap_get(other_config, "interconn-ts");
-        if (!interconn_ts && is_vxlan_mode(sbrec_chassis_table) &&
-            tunnel_key >= 1 << 12) {
+        if (!interconn_ts && vxlan_mode && tunnel_key >= 1 << 12) {
             static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
             VLOG_WARN_RL(&rl, "Tunnel key %"PRIu32" for datapath %s is "
                          "incompatible with VXLAN", tunnel_key,
@@ -985,7 +987,6 @@  build_datapaths(struct ovsdb_idl_txn *ovnsb_txn,
                 const struct nbrec_logical_switch_table *nbrec_ls_table,
                 const struct nbrec_logical_router_table *nbrec_lr_table,
                 const struct sbrec_datapath_binding_table *sbrec_dp_table,
-                const struct sbrec_chassis_table *sbrec_chassis_table,
                 struct ovn_datapaths *ls_datapaths,
                 struct ovn_datapaths *lr_datapaths,
                 struct ovs_list *lr_list)
@@ -1000,12 +1001,11 @@  build_datapaths(struct ovsdb_idl_txn *ovnsb_txn,
     struct hmap dp_tnlids = HMAP_INITIALIZER(&dp_tnlids);
     struct ovn_datapath *od;
     LIST_FOR_EACH (od, list, &both) {
-        ovn_datapath_assign_requested_tnl_id(sbrec_chassis_table, &dp_tnlids,
-                                             od);
+        ovn_datapath_assign_requested_tnl_id(&dp_tnlids, od);
     }
     LIST_FOR_EACH (od, list, &nb_only) {
-        ovn_datapath_assign_requested_tnl_id(sbrec_chassis_table, &dp_tnlids,
-                                             od); }
+        ovn_datapath_assign_requested_tnl_id(&dp_tnlids, od);
+    }
 
     /* Keep nonconflicting tunnel IDs that are already assigned. */
     LIST_FOR_EACH (od, list, &both) {
@@ -1017,12 +1017,10 @@  build_datapaths(struct ovsdb_idl_txn *ovnsb_txn,
     /* Assign new tunnel ids where needed. */
     uint32_t hint = 0;
     LIST_FOR_EACH_SAFE (od, list, &both) {
-        ovn_datapath_allocate_key(sbrec_chassis_table,
-                                  datapaths, &dp_tnlids, od, &hint);
+        ovn_datapath_allocate_key(datapaths, &dp_tnlids, od, &hint);
     }
     LIST_FOR_EACH_SAFE (od, list, &nb_only) {
-        ovn_datapath_allocate_key(sbrec_chassis_table,
-                                  datapaths, &dp_tnlids, od, &hint);
+        ovn_datapath_allocate_key(datapaths, &dp_tnlids, od, &hint);
     }
 
     /* Sync tunnel ids from nb to sb. */
@@ -3982,16 +3980,14 @@  ovn_port_add_tnlid(struct ovn_port *op, uint32_t tunnel_key)
  * that the I-P engine can fallback to recompute if needed; otherwise return
  * true (even if the key is not allocated). */
 static bool
-ovn_port_assign_requested_tnl_id(
-    const struct sbrec_chassis_table *sbrec_chassis_table, struct ovn_port *op)
+ovn_port_assign_requested_tnl_id(struct ovn_port *op)
 {
     const struct smap *options = (op->nbsp
                                   ? &op->nbsp->options
                                   : &op->nbrp->options);
     uint32_t tunnel_key = smap_get_int(options, "requested-tnl-key", 0);
     if (tunnel_key) {
-        if (is_vxlan_mode(sbrec_chassis_table) &&
-                tunnel_key >= OVN_VXLAN_MIN_MULTICAST) {
+        if (vxlan_mode && tunnel_key >= OVN_VXLAN_MIN_MULTICAST) {
             static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
             VLOG_WARN_RL(&rl, "Tunnel key %"PRIu32" for port %s "
                          "is incompatible with VXLAN",
@@ -4011,11 +4007,10 @@  ovn_port_assign_requested_tnl_id(
 }
 
 static bool
-ovn_port_allocate_key(const struct sbrec_chassis_table *sbrec_chassis_table,
-                      struct ovn_port *op)
+ovn_port_allocate_key(struct ovn_port *op)
 {
     if (!op->tunnel_key) {
-        uint8_t key_bits = is_vxlan_mode(sbrec_chassis_table)? 12 : 16;
+        uint8_t key_bits = vxlan_mode ? 12 : 16;
         op->tunnel_key = ovn_allocate_tnlid(&op->od->port_tnlids, "port",
                                             1, (1u << (key_bits - 1)) - 1,
                                             &op->od->port_key_hint);
@@ -4035,7 +4030,6 @@  ovn_port_allocate_key(const struct sbrec_chassis_table *sbrec_chassis_table,
 static void
 build_ports(struct ovsdb_idl_txn *ovnsb_txn,
     const struct sbrec_port_binding_table *sbrec_port_binding_table,
-    const struct sbrec_chassis_table *sbrec_chassis_table,
     const struct sbrec_mirror_table *sbrec_mirror_table,
     const struct sbrec_mac_binding_table *sbrec_mac_binding_table,
     const struct sbrec_ha_chassis_group_table *sbrec_ha_chassis_group_table,
@@ -4069,10 +4063,10 @@  build_ports(struct ovsdb_idl_txn *ovnsb_txn,
     /* Assign explicitly requested tunnel ids first. */
     struct ovn_port *op;
     LIST_FOR_EACH (op, list, &both) {
-        ovn_port_assign_requested_tnl_id(sbrec_chassis_table, op);
+        ovn_port_assign_requested_tnl_id(op);
     }
     LIST_FOR_EACH (op, list, &nb_only) {
-        ovn_port_assign_requested_tnl_id(sbrec_chassis_table, op);
+        ovn_port_assign_requested_tnl_id(op);
     }
 
     /* Keep nonconflicting tunnel IDs that are already assigned. */
@@ -4084,14 +4078,14 @@  build_ports(struct ovsdb_idl_txn *ovnsb_txn,
 
     /* Assign new tunnel ids where needed. */
     LIST_FOR_EACH_SAFE (op, list, &both) {
-        if (!ovn_port_allocate_key(sbrec_chassis_table, op)) {
+        if (!ovn_port_allocate_key(op)) {
             sbrec_port_binding_delete(op->sb);
             ovs_list_remove(&op->list);
             ovn_port_destroy(ports, op);
         }
     }
     LIST_FOR_EACH_SAFE (op, list, &nb_only) {
-        if (!ovn_port_allocate_key(sbrec_chassis_table, op)) {
+        if (!ovn_port_allocate_key(op)) {
             ovs_list_remove(&op->list);
             ovn_port_destroy(ports, op);
         }
@@ -4303,14 +4297,13 @@  ls_port_init(struct ovn_port *op, struct ovsdb_idl_txn *ovnsb_txn,
              struct ovn_datapath *od,
              const struct sbrec_port_binding *sb,
              const struct sbrec_mirror_table *sbrec_mirror_table,
-             const struct sbrec_chassis_table *sbrec_chassis_table,
              struct ovsdb_idl_index *sbrec_chassis_by_name,
              struct ovsdb_idl_index *sbrec_chassis_by_hostname)
 {
     op->od = od;
     parse_lsp_addrs(op);
     /* Assign explicitly requested tunnel ids first. */
-    if (!ovn_port_assign_requested_tnl_id(sbrec_chassis_table, op)) {
+    if (!ovn_port_assign_requested_tnl_id(op)) {
         return false;
     }
     /* Keep nonconflicting tunnel IDs that are already assigned. */
@@ -4320,7 +4313,7 @@  ls_port_init(struct ovn_port *op, struct ovsdb_idl_txn *ovnsb_txn,
         }
     }
     /* Assign new tunnel ids where needed. */
-    if (!ovn_port_allocate_key(sbrec_chassis_table, op)) {
+    if (!ovn_port_allocate_key(op)) {
         return false;
     }
     /* Create new binding, if needed. */
@@ -4344,15 +4337,13 @@  ls_port_create(struct ovsdb_idl_txn *ovnsb_txn, struct hmap *ls_ports,
                const char *key, const struct nbrec_logical_switch_port *nbsp,
                struct ovn_datapath *od,
                const struct sbrec_mirror_table *sbrec_mirror_table,
-               const struct sbrec_chassis_table *sbrec_chassis_table,
                struct ovsdb_idl_index *sbrec_chassis_by_name,
                struct ovsdb_idl_index *sbrec_chassis_by_hostname)
 {
     struct ovn_port *op = ovn_port_create(ls_ports, key, nbsp, NULL,
                                           NULL);
     hmap_insert(&od->ports, &op->dp_node, hmap_node_hash(&op->key_node));
-    if (!ls_port_init(op, ovnsb_txn, od, NULL,
-                      sbrec_mirror_table, sbrec_chassis_table,
+    if (!ls_port_init(op, ovnsb_txn, od, NULL, sbrec_mirror_table,
                       sbrec_chassis_by_name, sbrec_chassis_by_hostname)) {
         ovn_port_destroy(ls_ports, op);
         return NULL;
@@ -4367,7 +4358,6 @@  ls_port_reinit(struct ovn_port *op, struct ovsdb_idl_txn *ovnsb_txn,
                 struct ovn_datapath *od,
                 const struct sbrec_port_binding *sb,
                 const struct sbrec_mirror_table *sbrec_mirror_table,
-                const struct sbrec_chassis_table *sbrec_chassis_table,
                 struct ovsdb_idl_index *sbrec_chassis_by_name,
                 struct ovsdb_idl_index *sbrec_chassis_by_hostname)
 {
@@ -4375,8 +4365,7 @@  ls_port_reinit(struct ovn_port *op, struct ovsdb_idl_txn *ovnsb_txn,
     op->sb = sb;
     ovn_port_set_nb(op, nbsp, NULL);
     op->l3dgw_port = op->cr_port = NULL;
-    return ls_port_init(op, ovnsb_txn, od, sb,
-                        sbrec_mirror_table, sbrec_chassis_table,
+    return ls_port_init(op, ovnsb_txn, od, sb, sbrec_mirror_table,
                         sbrec_chassis_by_name, sbrec_chassis_by_hostname);
 }
 
@@ -4521,7 +4510,6 @@  ls_handle_lsp_changes(struct ovsdb_idl_txn *ovnsb_idl_txn,
             op = ls_port_create(ovnsb_idl_txn, &nd->ls_ports,
                                 new_nbsp->name, new_nbsp, od,
                                 ni->sbrec_mirror_table,
-                                ni->sbrec_chassis_table,
                                 ni->sbrec_chassis_by_name,
                                 ni->sbrec_chassis_by_hostname);
             if (!op) {
@@ -4553,7 +4541,6 @@  ls_handle_lsp_changes(struct ovsdb_idl_txn *ovnsb_idl_txn,
             if (!ls_port_reinit(op, ovnsb_idl_txn,
                                 new_nbsp,
                                 od, sb, ni->sbrec_mirror_table,
-                                ni->sbrec_chassis_table,
                                 ni->sbrec_chassis_by_name,
                                 ni->sbrec_chassis_by_hostname)) {
                 if (sb) {
@@ -17609,11 +17596,12 @@  ovnnb_db_run(struct northd_input *input_data,
     use_common_zone = smap_get_bool(input_data->nb_options, "use_common_zone",
                                     false);
 
+    init_vxlan_mode(input_data->sbrec_chassis_table);
+
     build_datapaths(ovnsb_txn,
                     input_data->nbrec_logical_switch_table,
                     input_data->nbrec_logical_router_table,
                     input_data->sbrec_datapath_binding_table,
-                    input_data->sbrec_chassis_table,
                     &data->ls_datapaths,
                     &data->lr_datapaths, &data->lr_list);
     build_lb_datapaths(input_data->lbs, input_data->lbgrps,
@@ -17621,7 +17609,6 @@  ovnnb_db_run(struct northd_input *input_data,
                        &data->lb_datapaths_map, &data->lb_group_datapaths_map);
     build_ports(ovnsb_txn,
                 input_data->sbrec_port_binding_table,
-                input_data->sbrec_chassis_table,
                 input_data->sbrec_mirror_table,
                 input_data->sbrec_mac_binding_table,
                 input_data->sbrec_ha_chassis_group_table,
diff --git a/northd/northd.h b/northd/northd.h
index 940926945..be480003e 100644
--- a/northd/northd.h
+++ b/northd/northd.h
@@ -791,6 +791,9 @@  lr_has_multiple_gw_ports(const struct ovn_datapath *od)
     return od->n_l3dgw_ports > 1 && !od->is_gw_router;
 }
 
-uint32_t get_ovn_max_dp_key_local(const struct sbrec_chassis_table *);
+void
+init_vxlan_mode(const struct sbrec_chassis_table *sbrec_chassis_table);
+
+uint32_t get_ovn_max_dp_key_local(void);
 
 #endif /* NORTHD_H */
diff --git a/ovn-architecture.7.xml b/ovn-architecture.7.xml
index bfd8680ce..3ecb58933 100644
--- a/ovn-architecture.7.xml
+++ b/ovn-architecture.7.xml
@@ -2809,11 +2809,11 @@ 
   </ul>
 
   <p>
-      When VXLAN is enabled on any hypervisor in a cluster, datapath and egress
-      port identifier ranges are reduced to 12-bits. This is done because only
-      STT and Geneve provide the large space for metadata (over 32 bits per
-      packet). To accommodate for VXLAN, 24 bits available are split as
-      follows:
+    When VXLAN is enabled on any hypervisor in a cluster, datapath and egress
+    port identifier ranges are reduced to 12-bits.  This is done because only
+    STT and Geneve provide the large space for metadata (over 32 bits per
+    packet).  The mode with reduced ranges is called <code>VXLAN mode</code>.
+    To accommodate for VXLAN, 24 bits available are split as follows:
   </p>
 
   <ul>