vhost: add packed ring single dequeue

Add vhost single packet dequeue function for packed ring and meanwhile
left space for shadow used ring update function.

Signed-off-by: Marvin Liu <yong.liu@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 4ddf265..87f2ae4 100644 (file)
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1635,6 +1635,61 @@ virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
        return i;
 }
 
+static __rte_always_inline int
+vhost_dequeue_single_packed(struct virtio_net *dev,
+                           struct vhost_virtqueue *vq,
+                           struct rte_mempool *mbuf_pool,
+                           struct rte_mbuf **pkts,
+                           uint16_t *buf_id,
+                           uint16_t *desc_count)
+{
+       struct buf_vector buf_vec[BUF_VECTOR_MAX];
+       uint32_t buf_len;
+       uint16_t nr_vec = 0;
+       int err;
+
+       if (unlikely(fill_vec_buf_packed(dev, vq,
+                                        vq->last_avail_idx, desc_count,
+                                        buf_vec, &nr_vec,
+                                        buf_id, &buf_len,
+                                        VHOST_ACCESS_RO) < 0))
+               return -1;
+
+       *pkts = virtio_dev_pktmbuf_alloc(dev, mbuf_pool, buf_len);
+       if (unlikely(*pkts == NULL)) {
+               RTE_LOG(ERR, VHOST_DATA,
+                       "Failed to allocate memory for mbuf.\n");
+               return -1;
+       }
+
+       err = copy_desc_to_mbuf(dev, vq, buf_vec, nr_vec, *pkts,
+                               mbuf_pool);
+       if (unlikely(err)) {
+               rte_pktmbuf_free(*pkts);
+               return -1;
+       }
+
+       return 0;
+}
+
+static __rte_unused int
+virtio_dev_tx_single_packed(struct virtio_net *dev,
+                           struct vhost_virtqueue *vq,
+                           struct rte_mempool *mbuf_pool,
+                           struct rte_mbuf **pkts)
+{
+
+       uint16_t buf_id, desc_count;
+
+       if (vhost_dequeue_single_packed(dev, vq, mbuf_pool, pkts, &buf_id,
+                                       &desc_count))
+               return -1;
+
+       vq_inc_last_avail_packed(vq, desc_count);
+
+       return 0;
+}
+
 static __rte_noinline uint16_t
 virtio_dev_tx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
        struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)