netdev-dpdk: Set Vhost port maximum number of queue pairs.

This patch uses the new rte_vhost_driver_set_max_queue_num API to set the maximum number of queue pairs supported by the Vhost-user port. This is required for VDUSE which needs to specify the maximum number of queue pairs at creation time. Without it 128 queue pairs metadata would be allocated. To configure it, a new 'vhost-queue-pairs-max' option is introduced. Signed-off-by: Maxime Coquelin <[email protected]> Acked-by: Eelco Chaudron <[email protected]> Signed-off-by: 0-day Robot <[email protected]>
ovsrobot · Dec 4, 2024 · e29d1b7 · e29d1b7
1 parent 77ac0b2
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diff --git a/Documentation/topics/dpdk/vhost-user.rst b/Documentation/topics/dpdk/vhost-user.rst
@@ -375,6 +375,21 @@ Tx retries max can be set for vhost-user-client ports::
 
   Configurable vhost tx retries are not supported with vhost-user ports.
 
+vhost-user-client max queue pairs config
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For vhost-user-client interfaces using the VDUSE backend, the maximum umber of
+queue pairs the Virtio device will support can be set at port creation time. If
+not set, the default value is 1 queue pair. As of DPDK v24.11, this value is
+ignored for Vhost-user backends.
+
+Maximum number of queue pairs can be set for vhost-user-client-ports::
+
+    $ ovs-vsctl add-port br0 vduse0 \
+        -- set Interface vduse0 type=dpdkvhostuserclient \
+            options:vhost-server-path=/dev/vduse/vduse0 \
+            options:vhost-queue-pairs-max=4
+
 .. _dpdk-testpmd:
 
 DPDK in the Guest

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
@@ -19,6 +19,7 @@
 
 #include <errno.h>
 #include <signal.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -153,6 +154,9 @@ typedef uint16_t dpdk_port_t;
 /* Legacy default value for vhost tx retries. */
 #define VHOST_ENQ_RETRY_DEF 8
 
+/* VDUSE-only, ignore for Vhost-user */
+#define VHOST_QUEUE_PAIRS_MAX_DEF 1
+
 #define IF_NAME_SZ (PATH_MAX > IFNAMSIZ ? PATH_MAX : IFNAMSIZ)
 
 /* List of required flags advertised by the hardware that will be used
@@ -497,6 +501,9 @@ struct netdev_dpdk {
 
         atomic_uint8_t vhost_tx_retries_max;
 
+        /* Ignored by DPDK for Vhost-user backends, only for VDUSE */
+        uint32_t vhost_queue_pairs_max;
+
         /* Flags for virtio features recovery mechanism. */
         uint8_t virtio_features_state;
 
@@ -1609,6 +1616,8 @@ vhost_common_construct(struct netdev *netdev)
 
     atomic_init(&dev->vhost_tx_retries_max, VHOST_ENQ_RETRY_DEF);
 
+    dev->vhost_queue_pairs_max = VHOST_QUEUE_PAIRS_MAX_DEF;
+
     return common_construct(netdev, DPDK_ETH_PORT_ID_INVALID,
                             DPDK_DEV_VHOST, socket_id);
 }
@@ -2491,13 +2500,22 @@ netdev_dpdk_vhost_client_set_config(struct netdev *netdev,
     struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
     const char *path;
     int max_tx_retries, cur_max_tx_retries;
+    uint32_t queue_pairs_max;
 
     ovs_mutex_lock(&dev->mutex);
     if (!(dev->vhost_driver_flags & RTE_VHOST_USER_CLIENT)) {
         path = smap_get(args, "vhost-server-path");
         if (!nullable_string_is_equal(path, dev->vhost_id)) {
             free(dev->vhost_id);
             dev->vhost_id = nullable_xstrdup(path);
+
+            queue_pairs_max = smap_get_int(args, "vhost-queue-pairs-max",
+                                           VHOST_QUEUE_PAIRS_MAX_DEF);
+            if (queue_pairs_max < 1) {
+                queue_pairs_max = VHOST_QUEUE_PAIRS_MAX_DEF;
+            }
+            dev->vhost_queue_pairs_max = queue_pairs_max;
+
             netdev_request_reconfigure(netdev);
         }
     }
@@ -2514,6 +2532,7 @@ netdev_dpdk_vhost_client_set_config(struct netdev *netdev,
         VLOG_INFO("Max Tx retries for vhost device '%s' set to %d",
                   netdev_get_name(netdev), max_tx_retries);
     }
+
     ovs_mutex_unlock(&dev->mutex);
 
     return 0;
@@ -6400,6 +6419,14 @@ netdev_dpdk_vhost_client_reconfigure(struct netdev *netdev)
             goto unlock;
         }
 
+        err = rte_vhost_driver_set_max_queue_num(dev->vhost_id,
+                                                 dev->vhost_queue_pairs_max);
+        if (err) {
+            VLOG_ERR("rte_vhost_driver_set_max_queue_num failed for "
+                    "vhost-user client port: %s\n", dev->up.name);
+            goto unlock;
+        }
+
         err = rte_vhost_driver_start(dev->vhost_id);
         if (err) {
             VLOG_ERR("rte_vhost_driver_start failed for vhost user "