> -----Original Message-----
> From: Maxime Coquelin <maxime.coque...@redhat.com>
> Sent: Wednesday, October 27, 2021 12:29 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo....@intel.com>; Hu, Jiayu
> <jiayu...@intel.com>; Wang, YuanX <yuanx.w...@intel.com>; Ma, WenwuX
> <wenwux...@intel.com>; Richardson, Bruce <bruce.richard...@intel.com>;
> Mcnamara, John <john.mcnam...@intel.com>
> Cc: Maxime Coquelin <maxime.coque...@redhat.com>
> Subject: [PATCH v2 06/15] vhost: introduce specific iovec structure
>
> This patch introduces rte_vhost_iovec struct that contains
> both source and destination addresses since we always have
> a 1:1 mapping between source and destination. While using
> the standard iovec struct might have seemed better, having
> to duplicate IO vectors and its iterators is memory
> inefficient and make the implementation more complex.
>
> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
> ---
> examples/vhost/ioat.c | 24 ++++++-------
> lib/vhost/rte_vhost_async.h | 19 +++++++----
> lib/vhost/vhost.h | 6 ++--
> lib/vhost/virtio_net.c | 68 ++++++++++++++-----------------------
> 4 files changed, 52 insertions(+), 65 deletions(-)
>
> diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c
> index 457f8171f0..dcbcf65e4e 100644
> --- a/examples/vhost/ioat.c
> +++ b/examples/vhost/ioat.c
> @@ -129,33 +129,31 @@ ioat_transfer_data_cb(int vid, uint16_t queue_id,
> {
> uint32_t i_desc;
> uint16_t dev_id = dma_bind[vid].dmas[queue_id * 2 + VIRTIO_RXQ].dev_id;
> - struct rte_vhost_iov_iter *src = NULL;
> - struct rte_vhost_iov_iter *dst = NULL;
> + struct rte_vhost_iov_iter *iter = NULL;
> unsigned long i_seg;
> unsigned short mask = MAX_ENQUEUED_SIZE - 1;
> unsigned short write = cb_tracker[dev_id].next_write;
>
> if (!opaque_data) {
> for (i_desc = 0; i_desc < count; i_desc++) {
> - src = descs[i_desc].src;
> - dst = descs[i_desc].dst;
> + iter = descs[i_desc].iter;
> i_seg = 0;
> - if (cb_tracker[dev_id].ioat_space < src->nr_segs)
> + if (cb_tracker[dev_id].ioat_space < iter->nr_segs)
> break;
> - while (i_seg < src->nr_segs) {
> + while (i_seg < iter->nr_segs) {
> rte_ioat_enqueue_copy(dev_id,
> - (uintptr_t)(src->iov[i_seg].iov_base)
> - + src->offset,
> - (uintptr_t)(dst->iov[i_seg].iov_base)
> - + dst->offset,
> - src->iov[i_seg].iov_len,
> + (uintptr_t)(iter->iov[i_seg].src_addr)
> + + iter->offset,
> + (uintptr_t)(iter->iov[i_seg].dst_addr)
> + + iter->offset,
> + iter->iov[i_seg].len,
> 0,
> 0);
> i_seg++;
> }
> write &= mask;
> - cb_tracker[dev_id].size_track[write] = src->nr_segs;
> - cb_tracker[dev_id].ioat_space -= src->nr_segs;
> + cb_tracker[dev_id].size_track[write] = iter->nr_segs;
> + cb_tracker[dev_id].ioat_space -= iter->nr_segs;
> write++;
> }
> } else {
> diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
> index 789b80f5a0..d7bb77bf90 100644
> --- a/lib/vhost/rte_vhost_async.h
> +++ b/lib/vhost/rte_vhost_async.h
> @@ -7,6 +7,15 @@
>
> #include "rte_vhost.h"
>
> +/**
> + * iovec
> + */
> +struct rte_vhost_iovec {
> + void *src_addr;
> + void *dst_addr;
> + size_t len;
> +};
> +
> /**
> * iovec iterator
> */
> @@ -16,19 +25,17 @@ struct rte_vhost_iov_iter {
> /** total bytes of data in this iterator */
> size_t count;
> /** pointer to the iovec array */
> - struct iovec *iov;
> + struct rte_vhost_iovec *iov;
> /** number of iovec in this iterator */
> unsigned long nr_segs;
> };
>
> /**
> - * dma transfer descriptor pair
> + * dma transfer descriptor
> */
> struct rte_vhost_async_desc {
> - /** source memory iov_iter */
> - struct rte_vhost_iov_iter *src;
> - /** destination memory iov_iter */
> - struct rte_vhost_iov_iter *dst;
> + /* memory iov_iter */
> + struct rte_vhost_iov_iter *iter;
> };
>
> /**
> diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
> index 132c1b070e..e51e496ebe 100644
> --- a/lib/vhost/vhost.h
> +++ b/lib/vhost/vhost.h
> @@ -132,10 +132,8 @@ struct vhost_async {
> /* operation callbacks for DMA */
> struct rte_vhost_async_channel_ops ops;
>
> - struct rte_vhost_iov_iter src_iov_iter[VHOST_MAX_ASYNC_IT];
> - struct rte_vhost_iov_iter dst_iov_iter[VHOST_MAX_ASYNC_IT];
> - struct iovec src_iovec[VHOST_MAX_ASYNC_VEC];
> - struct iovec dst_iovec[VHOST_MAX_ASYNC_VEC];
> + struct rte_vhost_iov_iter iov_iter[VHOST_MAX_ASYNC_IT];
> + struct rte_vhost_iovec iovec[VHOST_MAX_ASYNC_VEC];
>
> /* data transfer status */
> struct async_inflight_info *pkts_info;
> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
> index c4a8b5276f..3c8be48ca7 100644
> --- a/lib/vhost/virtio_net.c
> +++ b/lib/vhost/virtio_net.c
> @@ -925,15 +925,16 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct
> vhost_virtqueue *vq,
> }
>
> static __rte_always_inline void
> -async_fill_vec(struct iovec *v, void *base, size_t len)
> +async_fill_vec(struct rte_vhost_iovec *v, void *src, void *dst, size_t len)
> {
> - v->iov_base = base;
> - v->iov_len = len;
> + v->src_addr = src;
> + v->dst_addr = dst;
> + v->len = len;
> }
>
> static __rte_always_inline void
> async_fill_iter(struct rte_vhost_iov_iter *it, size_t count,
> - struct iovec *vec, unsigned long nr_seg)
> + struct rte_vhost_iovec *vec, unsigned long nr_seg)
> {
> it->offset = 0;
> it->count = count;
> @@ -948,20 +949,16 @@ async_fill_iter(struct rte_vhost_iov_iter *it, size_t
> count,
> }
>
> static __rte_always_inline void
> -async_fill_desc(struct rte_vhost_async_desc *desc,
> - struct rte_vhost_iov_iter *src, struct rte_vhost_iov_iter *dst)
> +async_fill_desc(struct rte_vhost_async_desc *desc, struct rte_vhost_iov_iter
> *iter)
> {
> - desc->src = src;
> - desc->dst = dst;
> + desc->iter = iter;
> }
>
> static __rte_always_inline int
> async_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
> struct rte_mbuf *m, struct buf_vector *buf_vec,
> uint16_t nr_vec, uint16_t num_buffers,
> - struct iovec *src_iovec, struct iovec *dst_iovec,
> - struct rte_vhost_iov_iter *src_it,
> - struct rte_vhost_iov_iter *dst_it)
> + struct rte_vhost_iovec *iovec, struct rte_vhost_iov_iter
> *iter)
> {
> struct rte_mbuf *hdr_mbuf;
> struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL;
> @@ -1075,11 +1072,9 @@ async_mbuf_to_desc(struct virtio_net *dev, struct
> vhost_virtqueue *vq,
> goto out;
> }
>
> - async_fill_vec(src_iovec + tvec_idx,
> + async_fill_vec(iovec + tvec_idx,
> (void *)(uintptr_t)rte_pktmbuf_iova_offset(m,
> - mbuf_offset), (size_t)mapped_len);
> - async_fill_vec(dst_iovec + tvec_idx,
> - hpa, (size_t)mapped_len);
> + mbuf_offset), hpa, (size_t)mapped_len);
>
> tlen += (uint32_t)mapped_len;
> cpy_len -= (uint32_t)mapped_len;
> @@ -1091,8 +1086,7 @@ async_mbuf_to_desc(struct virtio_net *dev, struct
> vhost_virtqueue *vq,
> }
> }
>
> - async_fill_iter(src_it, tlen, src_iovec, tvec_idx);
> - async_fill_iter(dst_it, tlen, dst_iovec, tvec_idx);
> + async_fill_iter(iter, tlen, iovec, tvec_idx);
> out:
> return error;
> }
> @@ -1509,11 +1503,9 @@ virtio_dev_rx_async_submit_split(struct virtio_net
> *dev,
> uint16_t avail_head;
>
> struct vhost_async *async = vq->async;
> - struct rte_vhost_iov_iter *src_iter = async->src_iov_iter;
> - struct rte_vhost_iov_iter *dst_iter = async->dst_iov_iter;
> + struct rte_vhost_iov_iter *iter = async->iov_iter;
> struct rte_vhost_async_desc tdes[MAX_PKT_BURST];
> - struct iovec *src_iovec = async->src_iovec;
> - struct iovec *dst_iovec = async->dst_iovec;
> + struct rte_vhost_iovec *iovec = async->iovec;
> struct async_inflight_info *pkts_info = async->pkts_info;
> uint32_t n_pkts = 0, pkt_err = 0;
> int32_t n_xfer;
> @@ -1545,19 +1537,18 @@ virtio_dev_rx_async_submit_split(struct virtio_net
> *dev,
> vq->last_avail_idx + num_buffers);
>
> if (async_mbuf_to_desc(dev, vq, pkts[pkt_idx], buf_vec, nr_vec,
> num_buffers,
> - &src_iovec[iovec_idx], &dst_iovec[iovec_idx],
> - &src_iter[it_idx], &dst_iter[it_idx]) < 0) {
> + &iovec[iovec_idx], &iter[it_idx]) < 0) {
> vq->shadow_used_idx -= num_buffers;
> break;
> }
>
> - async_fill_desc(&tdes[pkt_burst_idx++], &src_iter[it_idx],
> &dst_iter[it_idx]);
> + async_fill_desc(&tdes[pkt_burst_idx++], &iter[it_idx]);
>
> slot_idx = (async->pkts_idx + pkt_idx) & (vq->size - 1);
> pkts_info[slot_idx].descs = num_buffers;
> pkts_info[slot_idx].mbuf = pkts[pkt_idx];
>
> - iovec_idx += src_iter[it_idx].nr_segs;
> + iovec_idx += iter[it_idx].nr_segs;
> it_idx++;
>
> vq->last_avail_idx += num_buffers;
> @@ -1707,9 +1698,8 @@ vhost_enqueue_async_packed(struct virtio_net *dev,
> struct buf_vector *buf_vec,
> uint16_t *nr_descs,
> uint16_t *nr_buffers,
> - struct iovec *src_iovec, struct iovec *dst_iovec,
> - struct rte_vhost_iov_iter *src_it,
> - struct rte_vhost_iov_iter *dst_it)
> + struct rte_vhost_iovec *iovec,
> + struct rte_vhost_iov_iter *iter)
> {
> uint16_t nr_vec = 0;
> uint16_t avail_idx = vq->last_avail_idx;
> @@ -1757,8 +1747,7 @@ vhost_enqueue_async_packed(struct virtio_net *dev,
> }
>
> if (unlikely(async_mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec,
> - *nr_buffers, src_iovec, dst_iovec,
> - src_it, dst_it) < 0))
> + *nr_buffers, iovec, iter) < 0))
> return -1;
>
> vhost_shadow_enqueue_packed(vq, buffer_len, buffer_buf_id,
> buffer_desc_count, *nr_buffers);
> @@ -1769,14 +1758,12 @@ vhost_enqueue_async_packed(struct virtio_net *dev,
> static __rte_always_inline int16_t
> virtio_dev_rx_async_packed(struct virtio_net *dev, struct vhost_virtqueue
> *vq,
> struct rte_mbuf *pkt, uint16_t *nr_descs, uint16_t
> *nr_buffers,
> - struct iovec *src_iovec, struct iovec *dst_iovec,
> - struct rte_vhost_iov_iter *src_it, struct
> rte_vhost_iov_iter *dst_it)
> + struct rte_vhost_iovec *iovec, struct
> rte_vhost_iov_iter
> *iter)
> {
> struct buf_vector buf_vec[BUF_VECTOR_MAX];
>
> if (unlikely(vhost_enqueue_async_packed(dev, vq, pkt, buf_vec, nr_descs,
> nr_buffers,
> - src_iovec, dst_iovec,
> - src_it, dst_it) < 0)) {
> + iovec, iter) < 0)) {
> VHOST_LOG_DATA(DEBUG, "(%d) failed to get enough desc from
> vring\n", dev->vid);
> return -1;
> }
> @@ -1825,11 +1812,9 @@ virtio_dev_rx_async_submit_packed(struct virtio_net
> *dev,
> uint16_t num_descs;
>
> struct vhost_async *async = vq->async;
> - struct rte_vhost_iov_iter *src_iter = async->src_iov_iter;
> - struct rte_vhost_iov_iter *dst_iter = async->dst_iov_iter;
> + struct rte_vhost_iov_iter *iter = async->iov_iter;
> struct rte_vhost_async_desc tdes[MAX_PKT_BURST];
> - struct iovec *src_iovec = async->src_iovec;
> - struct iovec *dst_iovec = async->dst_iovec;
> + struct rte_vhost_iovec *iovec = async->iovec;
> struct async_inflight_info *pkts_info = async->pkts_info;
> uint32_t n_pkts = 0, pkt_err = 0;
> uint16_t slot_idx = 0;
> @@ -1842,17 +1827,16 @@ virtio_dev_rx_async_submit_packed(struct virtio_net
> *dev,
> num_descs = 0;
> if (unlikely(virtio_dev_rx_async_packed(dev, vq, pkts[pkt_idx],
> &num_descs, &num_buffers,
> - &src_iovec[iovec_idx],
> &dst_iovec[iovec_idx],
> - &src_iter[it_idx],
> &dst_iter[it_idx]) < 0))
> + &iovec[iovec_idx],
> &iter[it_idx]) < 0))
> break;
>
> slot_idx = (async->pkts_idx + pkt_idx) % vq->size;
>
> - async_fill_desc(&tdes[pkt_burst_idx++], &src_iter[it_idx],
> &dst_iter[it_idx]);
> + async_fill_desc(&tdes[pkt_burst_idx++], &iter[it_idx]);
> pkts_info[slot_idx].descs = num_descs;
> pkts_info[slot_idx].nr_buffers = num_buffers;
> pkts_info[slot_idx].mbuf = pkts[pkt_idx];
> - iovec_idx += src_iter[it_idx].nr_segs;
> + iovec_idx += iter[it_idx].nr_segs;
> it_idx++;
>
> pkt_idx++;
> --
> 2.31.1
Reviewed-by: Chenbo Xia <chenbo....@intel.com>
