netdev-dpdk: Reset queue number for vhost devices on vm shutdown.

Rather than poll all disabled queues and waste some memory for vms that
have been shutdown, we can reconfigure when receiving a destroy
connection notification from the vhost library.

$ while true; do
  ovs-appctl dpif-netdev/pmd-rxq-show |awk '
  /port: / {
    tot++;
    if ($5 == "(enabled)") {
      en++;
    }
  }
  END {
    print "total: " tot ", enabled: " en
  }'
  sleep 1
done

total: 66, enabled: 66
total: 6, enabled: 2

This change requires a fix in the DPDK vhost library, so bump the minimal
required version to 18.11.2.

Co-authored-by: Ilya Maximets <i.maximets@samsung.com>
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Ian Stokes <ian.stokes@intel.com>

diff --git a/NEWS b/NEWS
index c03e2877551fea7486514c91df16d10eae34d502..2f8171f22ea774a409dd109d65e2d993a1f0ea14 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -4,7 +4,9 @@ Post-v2.11.0
      * New option 'other_config:dpdk-socket-limit' to limit amount of
        hugepage memory that can be used by DPDK.
      * Add support for vHost Post-copy Live Migration (experimental).
-     * OVS validated with DPDK 18.11.2 which is recommended to be used.
+     * OVS validated with DPDK 18.11.2 which is the new minimal supported
+       version.
+     * DPDK 18.11.1 and lower is no longer supported.
    - OpenFlow:
      * All features required by OpenFlow 1.5 are now implemented, so
        ovs-vswitchd now enables OpenFlow 1.5 by default (in addition to

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index b7f45438f7e70bc1a34f1cb7af8db86dfd1441f7..0b9bea405e694cc9e5bb8d0646f307d00ddbfc87 100644 (file)
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -185,12 +185,15 @@ static const struct rte_eth_conf port_conf = {
 static int new_device(int vid);
 static void destroy_device(int vid);
 static int vring_state_changed(int vid, uint16_t queue_id, int enable);
+static void destroy_connection(int vid);
 static const struct vhost_device_ops virtio_net_device_ops =
 {
     .new_device =  new_device,
     .destroy_device = destroy_device,
     .vring_state_changed = vring_state_changed,
-    .features_changed = NULL
+    .features_changed = NULL,
+    .new_connection = NULL,
+    .destroy_connection = destroy_connection,
 };
 
 enum { DPDK_RING_SIZE = 256 };
@@ -3663,6 +3666,48 @@ vring_state_changed(int vid, uint16_t queue_id, int enable)
     return 0;
 }
 
+static void
+destroy_connection(int vid)
+{
+    struct netdev_dpdk *dev;
+    char ifname[IF_NAME_SZ];
+    bool exists = false;
+
+    rte_vhost_get_ifname(vid, ifname, sizeof ifname);
+
+    ovs_mutex_lock(&dpdk_mutex);
+    LIST_FOR_EACH (dev, list_node, &dpdk_list) {
+        ovs_mutex_lock(&dev->mutex);
+        if (nullable_string_is_equal(ifname, dev->vhost_id)) {
+            uint32_t qp_num = NR_QUEUE;
+
+            if (netdev_dpdk_get_vid(dev) >= 0) {
+                VLOG_ERR("Connection on socket '%s' destroyed while vhost "
+                         "device still attached.", dev->vhost_id);
+            }
+
+            /* Restore the number of queue pairs to default. */
+            if (dev->requested_n_txq != qp_num
+                || dev->requested_n_rxq != qp_num) {
+                dev->requested_n_rxq = qp_num;
+                dev->requested_n_txq = qp_num;
+                netdev_request_reconfigure(&dev->up);
+            }
+            ovs_mutex_unlock(&dev->mutex);
+            exists = true;
+            break;
+        }
+        ovs_mutex_unlock(&dev->mutex);
+    }
+    ovs_mutex_unlock(&dpdk_mutex);
+
+    if (exists) {
+        VLOG_INFO("vHost Device '%s' connection has been destroyed", ifname);
+    } else {
+        VLOG_INFO("vHost Device '%s' not found", ifname);
+    }
+}
+
 /*
  * Retrieve the DPDK virtio device ID (vid) associated with a vhostuser
  * or vhostuserclient netdev.