examples/vhost: fix corrupted vdev tailq list

There are two tailq lists, one for logging all vhost devices, another
one for logging vhost devices distributed on a specific core. However,
there is just one tailq entry, named "next", to chain the two list,
which is wrong and could result to a corrupted tailq list, that the
tailq list might always be non-empty: the entry is still there even
after you have invoked TAILQ_REMOVE several times.

Fix it by introducing two tailq entries, one for each list.

Fixes: 45657a5c6861 ("examples/vhost: use tailq to link vhost devices")

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index f849571..671a7eb 100644 (file)
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -691,7 +691,7 @@ find_vhost_dev(struct ether_addr *mac)
 {
        struct vhost_dev *vdev;
 
-       TAILQ_FOREACH(vdev, &vhost_dev_list, next) {
+       TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
                if (vdev->ready == DEVICE_RX &&
                    is_same_ether_addr(mac, &vdev->mac_address))
                        return vdev;
@@ -945,7 +945,7 @@ virtio_tx_route(struct vhost_dev *vdev, struct rte_mbuf *m, uint16_t vlan_tag)
        if (unlikely(is_broadcast_ether_addr(&nh->d_addr))) {
                struct vhost_dev *vdev2;
 
-               TAILQ_FOREACH(vdev2, &vhost_dev_list, next) {
+               TAILQ_FOREACH(vdev2, &vhost_dev_list, global_vdev_entry) {
                        virtio_xmit(vdev2, vdev, m);
                }
                goto queue2nic;
@@ -1149,7 +1149,8 @@ switch_worker(void *arg __rte_unused)
                /*
                 * Process vhost devices
                 */
-               TAILQ_FOREACH(vdev, &lcore_info[lcore_id].vdev_list, next) {
+               TAILQ_FOREACH(vdev, &lcore_info[lcore_id].vdev_list,
+                             lcore_vdev_entry) {
                        if (unlikely(vdev->remove)) {
                                unlink_vmdq(vdev);
                                vdev->ready = DEVICE_SAFE_REMOVE;
@@ -1188,8 +1189,10 @@ destroy_device (volatile struct virtio_net *dev)
                rte_pause();
        }
 
-       TAILQ_REMOVE(&lcore_info[vdev->coreid].vdev_list, vdev, next);
-       TAILQ_REMOVE(&vhost_dev_list, vdev, next);
+       TAILQ_REMOVE(&lcore_info[vdev->coreid].vdev_list, vdev,
+                    lcore_vdev_entry);
+       TAILQ_REMOVE(&vhost_dev_list, vdev, global_vdev_entry);
+
 
        /* Set the dev_removal_flag on each lcore. */
        RTE_LCORE_FOREACH_SLAVE(lcore)
@@ -1234,7 +1237,7 @@ new_device (struct virtio_net *dev)
        vdev->dev = dev;
        dev->priv = vdev;
 
-       TAILQ_INSERT_TAIL(&vhost_dev_list, vdev, next);
+       TAILQ_INSERT_TAIL(&vhost_dev_list, vdev, global_vdev_entry);
        vdev->vmdq_rx_q
                = dev->device_fh * queues_per_pool + vmdq_queue_base;
 
@@ -1251,7 +1254,8 @@ new_device (struct virtio_net *dev)
        }
        vdev->coreid = core_add;
 
-       TAILQ_INSERT_TAIL(&lcore_info[vdev->coreid].vdev_list, vdev, next);
+       TAILQ_INSERT_TAIL(&lcore_info[vdev->coreid].vdev_list, vdev,
+                         lcore_vdev_entry);
        lcore_info[vdev->coreid].device_num++;
 
        /* Disable notifications. */
@@ -1294,7 +1298,7 @@ print_stats(void)
                printf("%s%s\n", clr, top_left);
                printf("Device statistics =================================\n");
 
-               TAILQ_FOREACH(vdev, &vhost_dev_list, next) {
+               TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
                        tx_total   = vdev->stats.tx_total;
                        tx         = vdev->stats.tx;
                        tx_dropped = tx_total - tx;

diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index c4591b4..bd7f1a3 100644 (file)
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -67,7 +67,8 @@ struct vhost_dev {
        volatile uint8_t remove;
 
        struct device_statistics stats;
-       TAILQ_ENTRY(vhost_dev) next;
+       TAILQ_ENTRY(vhost_dev) global_vdev_entry;
+       TAILQ_ENTRY(vhost_dev) lcore_vdev_entry;
 } __rte_cache_aligned;
 
 TAILQ_HEAD(vhost_dev_tailq_list, vhost_dev);