Re: [dpdk-dev] [PATCH v6 13/15] vhost: add Tx support for packed ring

[Tiwei Bie <tiwei.bie@intel.com>]

On Mon, Jul 02, 2018 at 10:16:27AM +0200, Maxime Coquelin wrote:
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/librte_vhost/vhost.h      |   1 +
>  lib/librte_vhost/virtio_net.c | 121 +++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 121 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index a7320469a..6ea8fb896 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -56,6 +56,7 @@ struct buf_vector {
>  struct zcopy_mbuf {
>  	struct rte_mbuf *mbuf;
>  	uint32_t desc_idx;
> +	uint16_t desc_count;
>  	uint16_t in_use;
>  
>  	TAILQ_ENTRY(zcopy_mbuf) next;
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index 2e286e228..03dd38235 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -1445,6 +1445,122 @@ virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
>  	return i;
>  }
>  
> +static __rte_always_inline 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)
> +{
> +	uint16_t i;
> +
> +	rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]);
> +
> +	if (unlikely(dev->dequeue_zero_copy)) {
> +		struct zcopy_mbuf *zmbuf, *next;
> +		int nr_updated = 0;
> +
> +		for (zmbuf = TAILQ_FIRST(&vq->zmbuf_list);
> +		     zmbuf != NULL; zmbuf = next) {
> +			next = TAILQ_NEXT(zmbuf, next);
> +
> +			if (mbuf_is_consumed(zmbuf->mbuf)) {
> +				update_shadow_used_ring_packed(vq,
> +						zmbuf->desc_idx,
> +						0,
> +						zmbuf->desc_count);
> +				nr_updated += 1;

nr_updated isn't really used.

> +
> +				TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next);
> +				restore_mbuf(zmbuf->mbuf);
> +				rte_pktmbuf_free(zmbuf->mbuf);
> +				put_zmbuf(zmbuf);
> +				vq->nr_zmbuf -= 1;
> +			}
> +		}
> +
> +		flush_shadow_used_ring_packed(dev, vq);
> +		vhost_vring_call(dev, vq);
> +	}
> +
[...]