vhost: remove fallback in async enqueue API

By design, async enqueue API should return directly if async device
is not registered. This patch removes the corrupted implementation of
the enqueue fallback from async mode to sync mode.

Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")
Cc: stable@dpdk.org
Signed-off-by: Patrick Fu <patrick.fu@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 3a019b7..0307956 100644 (file)
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1714,7 +1714,6 @@ virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
 {
        struct vhost_virtqueue *vq;
        uint32_t nb_tx = 0;
-       bool drawback = false;
 
        VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
        if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
@@ -1727,13 +1726,8 @@ virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
 
        rte_spinlock_lock(&vq->access_lock);
 
-       if (unlikely(vq->enabled == 0))
-               goto out_access_unlock;
-
-       if (unlikely(!vq->async_registered)) {
-               drawback = true;
+       if (unlikely(vq->enabled == 0 || !vq->async_registered))
                goto out_access_unlock;
-       }
 
        if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
                vhost_user_iotlb_rd_lock(vq);
@@ -1760,9 +1754,6 @@ out:
 out_access_unlock:
        rte_spinlock_unlock(&vq->access_lock);
 
-       if (drawback)
-               return rte_vhost_enqueue_burst(dev->vid, queue_id, pkts, count);
-
        return nb_tx;
 }