[v1,01/14] vhost: add single packet enqueue function
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Commit Message
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>
Comments
This code could be more concise.
> +/*
> + * Returns -1 on fail, 0 on success
> + */
That is standard convention, and probably doesn't need a comment.
> +static 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;
> + uint16_t max_tries, tries = 0;
> +
> + uint16_t buf_id = 0;
> + uint32_t len = 0;
> + uint16_t desc_count;
You don't need extra blank lines in declarations.
> +
> + uint32_t size = pkt->pkt_len + dev->vhost_hlen;
> + avail_idx = vq->last_avail_idx;
> +
> + if (rxvq_is_mergeable(dev))
> + max_tries = vq->size - 1;
> + else
> + max_tries = 1;
> +
> + uint16_t num_buffers = 0;
> +
> + 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;
> + }
Brackets are not necessary on single statement return.
> + len = RTE_MIN(len, size);
> +
> + size -= len;
No need for blank line in between.
> +
> + avail_idx += desc_count;
> + if (avail_idx >= vq->size)
> + avail_idx -= vq->size;
> +
> + *nr_descs += desc_count;
> + num_buffers += 1;
> + }
> +
> + if (copy_mbuf_to_desc(dev, vq, pkt,
> + buf_vec, nr_vec,
> + num_buffers) < 0) {
> + return 0;
> + }
> +
> + return 0;
> +}
> +
> +
@@ -774,6 +774,71 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
return error;
}
+/*
+ * Returns -1 on fail, 0 on success
+ */
+static 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;
+ 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;
+ avail_idx = vq->last_avail_idx;
+
+ if (rxvq_is_mergeable(dev))
+ max_tries = vq->size - 1;
+ else
+ max_tries = 1;
+
+ uint16_t num_buffers = 0;
+
+ 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;
+
+ avail_idx += desc_count;
+ if (avail_idx >= vq->size)
+ avail_idx -= vq->size;
+
+ *nr_descs += desc_count;
+ num_buffers += 1;
+ }
+
+ if (copy_mbuf_to_desc(dev, vq, pkt,
+ buf_vec, nr_vec,
+ num_buffers) < 0) {
+ return 0;
+ }
+
+ 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)
@@ -831,6 +896,35 @@ 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 0;
+ }
+
+ 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->last_avail_idx += nr_descs;
+ if (vq->last_avail_idx >= vq->size) {
+ vq->last_avail_idx -= vq->size;
+ vq->avail_wrap_counter ^= 1;
+ }
+
+ return 1;
+}
+
static __rte_noinline uint32_t
virtio_dev_rx_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
struct rte_mbuf **pkts, uint32_t count)