netdev-dpdk: Don't use PMD driver if not configured successfully

When initialization of the DPDK PMD driver fails
(dpdk_eth_dev_init()), the reconfigure_datapath() function will remove
the port from dp_netdev, and the port is not used.

Now when bridge_reconfigure() is called again, no changes to the
previous failing netdev configuration are detected and therefore the
ports gets added to dp_netdev and used uninitialized. This is causing
exceptions...

The fix has two parts to it. First in netdev-dpdk.c we remember if the
DPDK port was started or not, and when calling
netdev_dpdk_reconfigure() we also try re-initialization if the port
was not already active. The second part of the change is in
dpif-netdev.c where it makes sure netdev_reconfigure() is called if
the port needs reconfiguration, as netdev_is_reconf_required() is only
true until netdev_reconfigure() is called (even if it fails).

Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Tested-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Ian Stokes <ian.stokes@intel.com>

lib/dpif-netdev.c

@@ -3146,8 +3146,6 @@ port_reconfigure(struct dp_netdev_port *port)
     struct netdev *netdev = port->netdev;
     int i, err;
 
-    port->need_reconfigure = false;
-
     /* Closes the existing 'rxq's. */
     for (i = 0; i < port->n_rxq; i++) {
         netdev_rxq_close(port->rxqs[i].rx);
@@ -3156,7 +3154,7 @@ port_reconfigure(struct dp_netdev_port *port)
     port->n_rxq = 0;
 
     /* Allows 'netdev' to apply the pending configuration changes. */
-    if (netdev_is_reconf_required(netdev)) {
+    if (netdev_is_reconf_required(netdev) || port->need_reconfigure) {
         err = netdev_reconfigure(netdev);
         if (err && (err != EOPNOTSUPP)) {
             VLOG_ERR("Failed to set interface %s new configuration",
@@ -3183,6 +3181,9 @@ port_reconfigure(struct dp_netdev_port *port)
     /* Parse affinity list to apply configuration for new queues. */
     dpif_netdev_port_set_rxq_affinity(port, port->rxq_affinity_list);
 
+    /* If reconfiguration was successful mark it as such, so we can use it */
+    port->need_reconfigure = false;
+
     return 0;
 }
 

lib/netdev-dpdk.c

@@ -390,6 +390,9 @@ struct netdev_dpdk {
     /* If true, device was attached by rte_eth_dev_attach(). */
     bool attached;
 
+    /* If true, rte_eth_dev_start() was successfully called */
+    bool started;
+
     /* In dpdk_list. */
     struct ovs_list list_node OVS_GUARDED_BY(dpdk_mutex);
 
@@ -847,6 +850,7 @@ dpdk_eth_dev_init(struct netdev_dpdk *dev)
                  rte_strerror(-diag));
         return -diag;
     }
+    dev->started = true;
 
     rte_eth_promiscuous_enable(dev->port_id);
     rte_eth_allmulticast_enable(dev->port_id);
@@ -1124,6 +1128,7 @@ netdev_dpdk_destruct(struct netdev *netdev)
     ovs_mutex_lock(&dpdk_mutex);
 
     rte_eth_dev_stop(dev->port_id);
+    dev->started = false;
 
     if (dev->attached) {
         rte_eth_dev_close(dev->port_id);
@@ -3243,13 +3248,15 @@ netdev_dpdk_reconfigure(struct netdev *netdev)
         && dev->lsc_interrupt_mode == dev->requested_lsc_interrupt_mode
         && dev->rxq_size == dev->requested_rxq_size
         && dev->txq_size == dev->requested_txq_size
-        && dev->socket_id == dev->requested_socket_id) {
+        && dev->socket_id == dev->requested_socket_id
+        && dev->started) {
         /* Reconfiguration is unnecessary */
 
         goto out;
     }
 
     rte_eth_dev_stop(dev->port_id);
+    dev->started = false;
 
     if (dev->mtu != dev->requested_mtu
         || dev->socket_id != dev->requested_socket_id) {