diff mbox

[ovs-dev,v3,3/6] netdev-dpdk: Add netdev_dpdk_vhost_txq_flush function.

Message ID 1498775976-4142-4-git-send-email-bhanuprakash.bodireddy@intel.com
State Not Applicable
Delegated to: Darrell Ball
Headers show

Commit Message

Bodireddy, Bhanuprakash June 29, 2017, 10:39 p.m. UTC
Add netdev_dpdk_vhost_txq_flush(), that flushes packets on vHost User
port queues. Also add netdev_dpdk_vhost_tx_burst() function that
uses rte_vhost_enqueue_burst() to enqueue burst of packets on vHost User
ports.

Signed-off-by: Bhanuprakash Bodireddy <bhanuprakash.bodireddy@intel.com>
Signed-off-by: Antonio Fischetti <antonio.fischetti@intel.com>
Co-authored-by: Antonio Fischetti <antonio.fischetti@intel.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
---
 lib/netdev-dpdk.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 108 insertions(+), 4 deletions(-)
diff mbox

Patch

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index dd42716..51d528d 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -307,12 +307,22 @@  struct dpdk_tx_queue {
                                     * pmd threads (see 'concurrent_txq'). */
     int map;                       /* Mapping of configured vhost-user queues
                                     * to enabled by guest. */
-    int dpdk_pkt_cnt;              /* Number of buffered packets waiting to
+    union {
+        int dpdk_pkt_cnt;          /* Number of buffered packets waiting to
                                       be sent on DPDK tx queue. */
-    struct rte_mbuf *dpdk_burst_pkts[INTERIM_QUEUE_BURST_THRESHOLD];
+        int vhost_pkt_cnt;         /* Number of buffered packets waiting to
+                                      be sent on vhost port. */
+    };
+
+    union {
+        struct rte_mbuf *dpdk_burst_pkts[INTERIM_QUEUE_BURST_THRESHOLD];
                                    /* Intermediate queue where packets can
                                     * be buffered to amortize the cost of MMIO
                                     * writes. */
+        struct dp_packet *vhost_burst_pkts[INTERIM_QUEUE_BURST_THRESHOLD];
+                                   /* Intermediate queue where packets can
+                                    * be buffered for vhost ports. */
+    };
 };
 
 /* dpdk has no way to remove dpdk ring ethernet devices
@@ -1717,6 +1727,88 @@  netdev_dpdk_vhost_update_tx_counters(struct netdev_stats *stats,
     }
 }
 
+static int
+netdev_dpdk_vhost_tx_burst(struct netdev_dpdk *dev, int qid)
+{
+    struct dpdk_tx_queue *txq = &dev->tx_q[qid];
+    struct rte_mbuf **cur_pkts = (struct rte_mbuf **)txq->vhost_burst_pkts;
+
+    int tx_vid = netdev_dpdk_get_vid(dev);
+    int tx_qid = qid * VIRTIO_QNUM + VIRTIO_RXQ;
+    uint32_t sent = 0;
+    uint32_t retries = 0;
+    uint32_t sum, total_pkts;
+
+    total_pkts = sum = txq->vhost_pkt_cnt;
+    do {
+        uint32_t ret;
+        ret = rte_vhost_enqueue_burst(tx_vid, tx_qid, &cur_pkts[sent], sum);
+        if (OVS_UNLIKELY(!ret)) {
+            /* No packets enqueued - do not retry. */
+            break;
+        } else {
+            /* Packet have been sent */
+            sent += ret;
+
+            /* 'sum' packet have to be retransmitted */
+            sum -= ret;
+        }
+    } while (sum && (retries++ < VHOST_ENQ_RETRY_NUM));
+
+    for (int i = 0; i < total_pkts; i++) {
+        dp_packet_delete(txq->vhost_burst_pkts[i]);
+    }
+
+    /* Reset pkt count */
+    txq->vhost_pkt_cnt = 0;
+
+    /* 'sum' refers to packets dropped */
+    return sum;
+}
+
+/* Flush the txq if there are any packets available. */
+static int
+netdev_dpdk_vhost_txq_flush(struct netdev *netdev, int qid,
+                            bool concurrent_txq OVS_UNUSED)
+{
+    struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
+    struct dpdk_tx_queue *txq;
+
+    qid = dev->tx_q[qid % netdev->n_txq].map;
+
+    /* The qid may be disabled in the guest and has been set to
+     * OVS_VHOST_QUEUE_DISABLED.
+     */
+    if (OVS_UNLIKELY(qid < 0)) {
+        return 0;
+    }
+
+    txq = &dev->tx_q[qid];
+    /* Increment the drop count and free the memory. */
+    if (OVS_UNLIKELY(!is_vhost_running(dev) ||
+                     !(dev->flags & NETDEV_UP))) {
+
+        if (txq->vhost_pkt_cnt) {
+            rte_spinlock_lock(&dev->stats_lock);
+            dev->stats.tx_dropped+= txq->vhost_pkt_cnt;
+            rte_spinlock_unlock(&dev->stats_lock);
+
+            for (int i = 0; i < txq->vhost_pkt_cnt; i++) {
+                dp_packet_delete(txq->vhost_burst_pkts[i]);
+            }
+            txq->vhost_pkt_cnt = 0;
+        }
+    }
+
+    if (OVS_LIKELY(txq->vhost_pkt_cnt)) {
+        rte_spinlock_lock(&dev->tx_q[qid].tx_lock);
+        netdev_dpdk_vhost_tx_burst(dev, qid);
+        rte_spinlock_unlock(&dev->tx_q[qid].tx_lock);
+    }
+
+    return 0;
+}
+
 static void
 __netdev_dpdk_vhost_send(struct netdev *netdev, int qid,
                          struct dp_packet **pkts, int cnt)
@@ -2717,6 +2809,17 @@  vring_state_changed(int vid, uint16_t queue_id, int enable)
             if (enable) {
                 dev->tx_q[qid].map = qid;
             } else {
+                /* If the queue is disabled in the guest, the corresponding qid
+                 * map shall be set to OVS_VHOST_QUEUE_DISABLED(-2).
+                 *
+                 * The packets that were queued in 'qid' could be potentially
+                 * stuck and needs be dropped.
+                 *
+                 * XXX: The queues may be already disabled on the guest so
+                 * flush function in this case only helps in updating stats
+                 * and freeing memory.
+                 */
+                netdev_dpdk_vhost_txq_flush(&dev->up, qid, 0);
                 dev->tx_q[qid].map = OVS_VHOST_QUEUE_DISABLED;
             }
             netdev_dpdk_remap_txqs(dev);
@@ -3400,7 +3503,8 @@  static const struct netdev_class dpdk_vhost_class =
         NULL,
         netdev_dpdk_vhost_reconfigure,
         netdev_dpdk_vhost_rxq_recv,
-        NULL);
+        netdev_dpdk_vhost_txq_flush);
+
 static const struct netdev_class dpdk_vhost_client_class =
     NETDEV_DPDK_CLASS(
         "dpdkvhostuserclient",
@@ -3416,7 +3520,7 @@  static const struct netdev_class dpdk_vhost_client_class =
         NULL,
         netdev_dpdk_vhost_client_reconfigure,
         netdev_dpdk_vhost_rxq_recv,
-        NULL);
+        netdev_dpdk_vhost_txq_flush);
 
 void
 netdev_dpdk_register(void)