vhost: add packed ring single enqueue

Add vhost enqueue function for single packet and meanwhile left space
for flush used ring 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 070d62b..4fb6552 100644 (file)
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -770,6 +770,60 @@ out:
        return error;
 }
 
+static __rte_always_inline int
+vhost_enqueue_single_packed(struct virtio_net *dev,
+                           struct vhost_virtqueue *vq,
+                           struct rte_mbuf *pkt,
+                           struct buf_vector *buf_vec,
+                           uint16_t *nr_descs)
+{
+       uint16_t nr_vec = 0;
+       uint16_t avail_idx = vq->last_avail_idx;
+       uint16_t max_tries, tries = 0;
+       uint16_t buf_id = 0;
+       uint32_t len = 0;
+       uint16_t desc_count;
+       uint32_t size = pkt->pkt_len + dev->vhost_hlen;
+       uint16_t num_buffers = 0;
+
+       if (rxvq_is_mergeable(dev))
+               max_tries = vq->size - 1;
+       else
+               max_tries = 1;
+
+       while (size > 0) {
+               /*
+                * if we tried all available ring items, and still
+                * can't get enough buf, it means something abnormal
+                * happened.
+                */
+               if (unlikely(++tries > max_tries))
+                       return -1;
+
+               if (unlikely(fill_vec_buf_packed(dev, vq,
+                                               avail_idx, &desc_count,
+                                               buf_vec, &nr_vec,
+                                               &buf_id, &len,
+                                               VHOST_ACCESS_RW) < 0))
+                       return -1;
+
+               len = RTE_MIN(len, size);
+               size -= len;
+
+               num_buffers += 1;
+
+               *nr_descs += desc_count;
+               avail_idx += desc_count;
+               if (avail_idx >= vq->size)
+                       avail_idx -= vq->size;
+       }
+
+       if (copy_mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, num_buffers) < 0)
+               return -1;
+
+       return 0;
+}
+
 static __rte_noinline uint32_t
 virtio_dev_rx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
        struct rte_mbuf **pkts, uint32_t count)
@@ -827,6 +881,32 @@ virtio_dev_rx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
        return pkt_idx;
 }
 
+static __rte_unused int16_t
+virtio_dev_rx_single_packed(struct virtio_net *dev,
+                           struct vhost_virtqueue *vq,
+                           struct rte_mbuf *pkt)
+{
+       struct buf_vector buf_vec[BUF_VECTOR_MAX];
+       uint16_t nr_descs = 0;
+
+       rte_smp_rmb();
+       if (unlikely(vhost_enqueue_single_packed(dev, vq, pkt, buf_vec,
+                                                &nr_descs) < 0)) {
+               VHOST_LOG_DEBUG(VHOST_DATA,
+                               "(%d) failed to get enough desc from vring\n",
+                               dev->vid);
+               return -1;
+       }
+
+       VHOST_LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
+                       dev->vid, vq->last_avail_idx,
+                       vq->last_avail_idx + nr_descs);
+
+       vq_inc_last_avail_packed(vq, nr_descs);
+
+       return 0;
+}
+
 static __rte_noinline uint32_t
 virtio_dev_rx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
        struct rte_mbuf **pkts, uint32_t count)