Re: [dpdk-dev] [PATCH v2] vhost: add support for packed ring in async vhost

["Jiang, Cheng1" <cheng1.jiang@intel.com>]

Hi,

> -----Original Message-----
> From: Liu, Yong <yong.liu@intel.com>
> Sent: Wednesday, March 24, 2021 5:19 PM
> To: Jiang, Cheng1 <cheng1.jiang@intel.com>; maxime.coquelin@redhat.com;
> Xia, Chenbo <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX
> <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Jiang,
> Cheng1 <cheng1.jiang@intel.com>
> Subject: RE: [dpdk-dev] [PATCH v2] vhost: add support for packed ring in
> async vhost
> 
> 
> 
> > -----Original Message-----
> > From: dev <dev-bounces@dpdk.org> On Behalf Of Cheng Jiang
> > Sent: Monday, March 22, 2021 2:15 PM
> > To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> > Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX
> > <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Jiang,
> > Cheng1 <cheng1.jiang@intel.com>
> > Subject: [dpdk-dev] [PATCH v2] vhost: add support for packed ring in
> > async vhost
> >
> > For now async vhost data path only supports split ring structure. In
> > order to make async vhost compatible with virtio 1.1 spec this patch
> > enables packed ring in async vhost data path.
> >
> > Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> > ---
> > v2:
> >   * fix wrong buffer index in rte_vhost_poll_enqueue_completed()
> >   * add async_buffers_packed memory free in vhost_free_async_mem()
> >
> >  lib/librte_vhost/rte_vhost_async.h |   1 +
> >  lib/librte_vhost/vhost.c           |  24 +-
> >  lib/librte_vhost/vhost.h           |   7 +-
> >  lib/librte_vhost/virtio_net.c      | 447 +++++++++++++++++++++++++++--
> >  4 files changed, 441 insertions(+), 38 deletions(-)
> >
> > diff --git a/lib/librte_vhost/rte_vhost_async.h
> > b/lib/librte_vhost/rte_vhost_async.h
> > index c855ff875..6faa31f5a 100644
> > --- a/lib/librte_vhost/rte_vhost_async.h
> > +++ b/lib/librte_vhost/rte_vhost_async.h
> > @@ -89,6 +89,7 @@ struct rte_vhost_async_channel_ops {  struct
> > async_inflight_info {  struct rte_mbuf *mbuf;  uint16_t descs; /* num
> > of descs inflight */
> > +uint16_t nr_buffers; /* num of buffers inflight for packed ring */
> >  };
> >
> >  /**
> > diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c index
> > 52ab93d1e..51b44d6f2 100644
> > --- a/lib/librte_vhost/vhost.c
> > +++ b/lib/librte_vhost/vhost.c
> > @@ -330,15 +330,20 @@ vhost_free_async_mem(struct vhost_virtqueue
> > *vq)
> >  {
> >  if (vq->async_pkts_info)
> >  rte_free(vq->async_pkts_info);
> > -if (vq->async_descs_split)
> > +if (vq->async_buffers_packed) {
> > +rte_free(vq->async_buffers_packed);
> > +vq->async_buffers_packed = NULL;
> > +} else {
> >  rte_free(vq->async_descs_split);
> > +vq->async_descs_split = NULL;
> > +}
> > +
> >  if (vq->it_pool)
> >  rte_free(vq->it_pool);
> >  if (vq->vec_pool)
> >  rte_free(vq->vec_pool);
> >
> >  vq->async_pkts_info = NULL;
> > -vq->async_descs_split = NULL;
> >  vq->it_pool = NULL;
> >  vq->vec_pool = NULL;
> >  }
> > @@ -1603,9 +1608,9 @@ int rte_vhost_async_channel_register(int vid,
> > uint16_t queue_id,  return -1;
> >
> >  /* packed queue is not supported */
> > -if (unlikely(vq_is_packed(dev) || !f.async_inorder)) {
> > +if (unlikely(!f.async_inorder)) {
> >  VHOST_LOG_CONFIG(ERR,
> > -"async copy is not supported on packed queue or non-inorder mode "
> > +"async copy is not supported on non-inorder mode "
> >  "(vid %d, qid: %d)\n", vid, queue_id);  return -1;  } @@ -1643,10
> > +1648,17 @@ int rte_vhost_async_channel_register(int vid, uint16_t
> > queue_id,  vq->vec_pool = rte_malloc_socket(NULL,
> VHOST_MAX_ASYNC_VEC
> > * sizeof(struct iovec),  RTE_CACHE_LINE_SIZE, node);
> > -vq->async_descs_split = rte_malloc_socket(NULL,
> > +if (vq_is_packed(dev)) {
> > +vq->async_buffers_packed = rte_malloc_socket(NULL, size *
> > +vq->sizeof(struct vring_used_elem_packed),
> > +RTE_CACHE_LINE_SIZE, node);
> > +} else {
> > +vq->async_descs_split = rte_malloc_socket(NULL,
> >  vq->size * sizeof(struct vring_used_elem),  RTE_CACHE_LINE_SIZE,
> > node); -if (!vq->async_descs_split || !vq->async_pkts_info ||
> > +}
> > +
> > +if (!vq->async_pkts_info ||
> >  !vq->it_pool || !vq->vec_pool) {
> >  vhost_free_async_mem(vq);
> >  VHOST_LOG_CONFIG(ERR,
> > diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> > 658f6fc28..d6324fbf8 100644
> > --- a/lib/librte_vhost/vhost.h
> > +++ b/lib/librte_vhost/vhost.h
> > @@ -206,9 +206,14 @@ struct vhost_virtqueue {  uint16_tasync_pkts_idx;
> > uint16_tasync_pkts_inflight_n;  uint16_tasync_last_pkts_n; -struct
> > vring_used_elem  *async_descs_split;
> > +union {
> > +struct vring_used_elem  *async_descs_split; struct
> > +vring_used_elem_packed *async_buffers_packed; };
> >  uint16_t async_desc_idx;
> > +uint16_t async_packed_buffer_idx;
> >  uint16_t last_async_desc_idx;
> > +uint16_t last_async_buffer_idx;
> >
> >  /* vq async features */
> >  boolasync_inorder;
> > diff --git a/lib/librte_vhost/virtio_net.c
> > b/lib/librte_vhost/virtio_net.c index 583bf379c..fa8c4f4fe 100644
> > --- a/lib/librte_vhost/virtio_net.c
> > +++ b/lib/librte_vhost/virtio_net.c
> > @@ -363,8 +363,7 @@
> > vhost_shadow_dequeue_single_packed_inorder(struct vhost_virtqueue
> *vq,
> > }
> >
> >  static __rte_always_inline void
> > -vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
> > -   struct vhost_virtqueue *vq,
> > +vhost_shadow_enqueue_packed(struct vhost_virtqueue *vq,
> >     uint32_t len[],
> >     uint16_t id[],
> >     uint16_t count[],
> > @@ -382,6 +381,17 @@ vhost_shadow_enqueue_single_packed(struct
> > virtio_net *dev,
> >  vq->shadow_aligned_idx += count[i];
> >  vq->shadow_used_idx++;
> >  }
> > +}
> > +
> > +static __rte_always_inline void
> > +vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
> > +   struct vhost_virtqueue *vq,
> > +   uint32_t len[],
> > +   uint16_t id[],
> > +   uint16_t count[],
> > +   uint16_t num_buffers)
> > +{
> > +vhost_shadow_enqueue_packed(vq, len, id, count, num_buffers);
> >
> >  if (vq->shadow_aligned_idx >= PACKED_BATCH_SIZE) {
> > do_data_copy_enqueue(dev, vq); @@ -1633,12 +1643,343 @@
> > virtio_dev_rx_async_submit_split(struct
> > virtio_net *dev,
> >  return pkt_idx;
> >  }
> >
> > +static __rte_always_inline int
> > +vhost_enqueue_async_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_buffers,
> > +    struct iovec *src_iovec, struct iovec *dst_iovec,
> > +    struct rte_vhost_iov_iter *src_it,
> > +    struct rte_vhost_iov_iter *dst_it) { 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 + sizeof(struct
> > virtio_net_hdr_mrg_rxbuf);
> > +uint32_t buffer_len[vq->size];
> > +uint16_t buffer_buf_id[vq->size];
> > +uint16_t buffer_desc_count[vq->size]; *nr_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;
> > +
> > +buffer_len[*nr_buffers] = len;
> > +buffer_buf_id[*nr_buffers] = buf_id;
> > +buffer_desc_count[*nr_buffers] = desc_count; *nr_buffers += 1;
> > +
> > +*nr_descs += desc_count;
> > +avail_idx += desc_count;
> > +if (avail_idx >= vq->size)
> > +avail_idx -= vq->size;
> > +}
> > +
> > +if (async_mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, *nr_buffers,
> > +src_iovec, dst_iovec, src_it, dst_it) < 0) return -1;
> > +
> > +vhost_shadow_enqueue_packed(vq, buffer_len, buffer_buf_id,
> > +   buffer_desc_count, *nr_buffers);
> > +
> > +return 0;
> > +}
> > +
> > +static __rte_always_inline int16_t
> > +virtio_dev_rx_async_single_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 buf_vector
> > +buf_vec[BUF_VECTOR_MAX]; *nr_descs = 0; *nr_buffers = 0;
> > +
> > +if (unlikely(vhost_enqueue_async_single_packed(dev, vq, pkt,
> > buf_vec,
> > + nr_descs,
> > + nr_buffers,
> > + src_iovec, dst_iovec,
> > + src_it, dst_it) < 0)) {
> > +VHOST_LOG_DATA(DEBUG,
> > +"(%d) failed to get enough desc from vring\n",
> > +dev->vid);
> > +return -1;
> > +}
> > +
> > +VHOST_LOG_DATA(DEBUG, "(%d) current index %d | end
> > index %d\n",
> > +dev->vid, vq->last_avail_idx,
> > +vq->last_avail_idx + *nr_descs);
> > +
> > +return 0;
> > +}
> > +
> > +static __rte_noinline uint32_t
> > +virtio_dev_rx_async_submit_packed(struct virtio_net *dev, struct
> > +vhost_virtqueue *vq, uint16_t queue_id, struct rte_mbuf **pkts,
> > +uint32_t count, struct rte_mbuf **comp_pkts, uint32_t *comp_count) {
> 
> Hi Cheng,
> There're some common parts in virtio_dev_rx_async_submit_packed and
> virtio_dev_rx_async_submit_split.
> We can abstract some functions for those common parts which can bring
> more clarity.

Sure, but the structure or variable used by packed ring and split ring are different, it may not be very suitable for abstraction, I will consider it again, thank you.

> 
> Also this patch may be too huge for reviewing, please separate it into few
> parts for better understanding.

I'll make it better in the next version.

> 
> Thanks,
> Marvin
> 
> > +uint32_t pkt_idx = 0, pkt_burst_idx = 0; uint16_t num_buffers;
> > +uint16_t num_desc;
> > +
> > +struct rte_vhost_iov_iter *it_pool = vq->it_pool; struct iovec
> > +*vec_pool = vq->vec_pool; struct rte_vhost_async_desc
> > +tdes[MAX_PKT_BURST]; struct iovec *src_iovec = vec_pool; struct iovec
> > +*dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >> 1); struct
> > +rte_vhost_iov_iter *src_it = it_pool; struct rte_vhost_iov_iter
> > +*dst_it = it_pool + 1; uint16_t slot_idx = 0; uint16_t segs_await =
> > +0; struct async_inflight_info *pkts_info = vq->async_pkts_info;
> > +uint32_t n_pkts = 0, pkt_err = 0; uint32_t num_async_pkts = 0,
> > +num_done_pkts = 0; struct { uint16_t pkt_idx; uint16_t
> > +last_avail_idx; } async_pkts_log[MAX_PKT_BURST];
> > +
> > +rte_prefetch0(&vq->desc[vq->last_avail_idx & (vq->size - 1)]);
> > +
> > +for (pkt_idx = 0; pkt_idx < count; pkt_idx++) { if
> > +(unlikely(virtio_dev_rx_async_single_packed(dev, vq, pkts[pkt_idx],
> > +&num_desc, &num_buffers, src_iovec, dst_iovec, src_it, dst_it) < 0))
> > +{ break; }
> > +
> > +VHOST_LOG_DATA(DEBUG, "(%d) current index %d | end
> > index %d\n",
> > +dev->vid, vq->last_avail_idx,
> > +vq->last_avail_idx + num_desc);
> > +
> > +slot_idx = (vq->async_pkts_idx + num_async_pkts) & (vq->size - 1); if
> > +(src_it->count) { uint16_t from, to;
> > +
> > +async_fill_desc(&tdes[pkt_burst_idx++], src_it, dst_it);
> > +pkts_info[slot_idx].descs = num_desc; pkts_info[slot_idx].nr_buffers
> > += num_buffers; pkts_info[slot_idx].mbuf = pkts[pkt_idx];
> > +async_pkts_log[num_async_pkts].pkt_idx = pkt_idx;
> > +async_pkts_log[num_async_pkts++].last_avail_idx =
> > +vq->last_avail_idx;
> > +src_iovec += src_it->nr_segs;
> > +dst_iovec += dst_it->nr_segs;
> > +src_it += 2;
> > +dst_it += 2;
> > +segs_await += src_it->nr_segs;
> > +
> > +/**
> > + * recover shadow used ring and keep DMA-occupied
> > + * descriptors.
> > + */
> > +from = vq->shadow_used_idx - num_buffers; to =
> > +vq->async_packed_buffer_idx & (vq->size - 1); if (num_buffers + to <=
> > +vq->size) { rte_memcpy(&vq->async_buffers_packed[to],
> > +&vq->shadow_used_packed[from],
> > +num_buffers *
> > +sizeof(struct
> > vring_used_elem_packed));
> > +} else {
> > +int size = vq->size - to;
> > +
> > +rte_memcpy(&vq->async_buffers_packed[to],
> > +&vq->shadow_used_packed[from],
> > +size *
> > +sizeof(struct
> > vring_used_elem_packed));
> > +rte_memcpy(vq->async_buffers_packed,
> > +&vq->shadow_used_packed[from +
> > +size], (num_buffers - size) *
> > +sizeof(struct
> > vring_used_elem_packed));
> > +}
> > +vq->async_packed_buffer_idx += num_buffers; shadow_used_idx -=
> > +vq->num_buffers;
> > +} else
> > +comp_pkts[num_done_pkts++] = pkts[pkt_idx];
> > +
> > +vq_inc_last_avail_packed(vq, num_desc);
> > +
> > +/*
> > + * conditions to trigger async device transfer:
> > + * - buffered packet number reaches transfer threshold
> > + * - unused async iov number is less than max vhost vector  */ if
> > +(unlikely(pkt_burst_idx >=
> > VHOST_ASYNC_BATCH_THRESHOLD ||
> > +((VHOST_MAX_ASYNC_VEC >> 1) - segs_await <
> > +BUF_VECTOR_MAX))) {
> > +n_pkts = vq->async_ops.transfer_data(dev->vid,
> > +queue_id, tdes, 0, pkt_burst_idx);
> > +src_iovec = vec_pool;
> > +dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >>
> > 1);
> > +src_it = it_pool;
> > +dst_it = it_pool + 1;
> > +segs_await = 0;
> > +vq->async_pkts_inflight_n += n_pkts;
> > +
> > +if (unlikely(n_pkts < pkt_burst_idx)) {
> > +/*
> > + * log error packets number here and do
> > actual
> > + * error processing when applications poll
> > + * completion
> > + */
> > +pkt_err = pkt_burst_idx - n_pkts;
> > +pkt_burst_idx = 0;
> > +break;
> > +}
> > +
> > +pkt_burst_idx = 0;
> > +}
> > +}
> > +
> > +if (pkt_burst_idx) {
> > +n_pkts = vq->async_ops.transfer_data(dev->vid,
> > +queue_id, tdes, 0, pkt_burst_idx);
> > +vq->async_pkts_inflight_n += n_pkts;
> > +
> > +if (unlikely(n_pkts < pkt_burst_idx)) pkt_err = pkt_burst_idx -
> > +n_pkts; }
> > +
> > +do_data_copy_enqueue(dev, vq);
> > +
> > +if (unlikely(pkt_err)) {
> > +uint16_t num_buffers = 0;
> > +
> > +num_async_pkts -= pkt_err;
> > +/* calculate the sum of descriptors of DMA-error packets. */ while
> > +(pkt_err-- > 0) { num_buffers += pkts_info[slot_idx & (vq->size -
> > +1)].nr_buffers; slot_idx--; }
> > +vq->async_packed_buffer_idx -= num_buffers;
> > +/* recover shadow used ring and available ring */
> > +vq->shadow_used_idx -= (vq->last_avail_idx -
> > +
> > async_pkts_log[num_async_pkts].last_avail_idx -
> > +num_buffers);
> 
> Could it possible that vq->last_avail_idx smaller than
> async_pkts_log[num_async_pkts].last_avail_idx when operations near the
> ring's boundary?

Yes, you are right. Will be fixed, thanks.

Cheng

> 
> > +vq->last_avail_idx =
> > +async_pkts_log[num_async_pkts].last_avail_idx;
> > +pkt_idx = async_pkts_log[num_async_pkts].pkt_idx;
> > +num_done_pkts = pkt_idx - num_async_pkts; }
> > +
> > +vq->async_pkts_idx += num_async_pkts;
> > +*comp_count = num_done_pkts;
> > +
> > +if (likely(vq->shadow_used_idx)) {
> > +vhost_flush_enqueue_shadow_packed(dev, vq);
> > +vhost_vring_call_packed(dev, vq); }
> > +
> > +return pkt_idx;
> > +}
> > +
> > +static __rte_always_inline void
> > +vhost_update_used_packed(struct virtio_net *dev,
> > +  struct vhost_virtqueue *vq,
> > +  struct vring_used_elem_packed
> > *shadow_ring,
> > +  uint16_t count)
> > +{
> > +if (count == 0)
> > +return;
> > +int i;
> > +uint16_t used_idx = vq->last_used_idx; uint16_t head_idx =
> > +vq->last_used_idx; uint16_t head_flags = 0;
> > +
> > +/* Split loop in two to save memory barriers */ for (i = 0; i <
> > +count; i++) {
> > +vq->desc_packed[used_idx].id = shadow_ring[i].id;
> > +vq->desc_packed[used_idx].len = shadow_ring[i].len;
> > +
> > +used_idx += shadow_ring[i].count;
> > +if (used_idx >= vq->size)
> > +used_idx -= vq->size;
> > +}
> > +
> > +/* The ordering for storing desc flags needs to be enforced. */
> > +rte_atomic_thread_fence(__ATOMIC_RELEASE);
> > +
> > +for (i = 0; i < count; i++) {
> > +uint16_t flags;
> > +
> > +if (vq->shadow_used_packed[i].len)
> > +flags = VRING_DESC_F_WRITE;
> > +else
> > +flags = 0;
> > +
> > +if (vq->used_wrap_counter) {
> > +flags |= VRING_DESC_F_USED;
> > +flags |= VRING_DESC_F_AVAIL;
> > +} else {
> > +flags &= ~VRING_DESC_F_USED;
> > +flags &= ~VRING_DESC_F_AVAIL;
> > +}
> > +
> > +if (i > 0) {
> > +vq->desc_packed[vq->last_used_idx].flags = flags;
> > +
> > +vhost_log_cache_used_vring(dev, vq,
> > +vq->last_used_idx *
> > +sizeof(struct vring_packed_desc),
> > +sizeof(struct vring_packed_desc));
> > +} else {
> > +head_idx = vq->last_used_idx;
> > +head_flags = flags;
> > +}
> > +
> > +vq_inc_last_used_packed(vq, shadow_ring[i].count); }
> > +
> > +vq->desc_packed[head_idx].flags = head_flags;
> > +
> > +vhost_log_cache_used_vring(dev, vq,
> > +head_idx *
> > +sizeof(struct vring_packed_desc),
> > +sizeof(struct vring_packed_desc));
> > +
> > +vhost_log_cache_sync(dev, vq);
> > +}
> > +
> >  uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
> > struct rte_mbuf **pkts, uint16_t count)  {  struct virtio_net *dev =
> > get_device(vid);  struct vhost_virtqueue *vq; -uint16_t n_pkts_cpl =
> > 0, n_pkts_put = 0, n_descs = 0;
> > +uint16_t n_pkts_cpl = 0, n_pkts_put = 0, n_descs = 0, n_buffers = 0;
> >  uint16_t start_idx, pkts_idx, vq_size;  struct async_inflight_info
> > *pkts_info;  uint16_t from, i; @@ -1680,53 +2021,96 @@ uint16_t
> > rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,  goto
> > done;  }
> >
> > -for (i = 0; i < n_pkts_put; i++) {
> > -from = (start_idx + i) & (vq_size - 1); -n_descs +=
> > pkts_info[from].descs; -pkts[i] = pkts_info[from].mbuf;
> > +if (vq_is_packed(dev)) {
> > +for (i = 0; i < n_pkts_put; i++) {
> > +from = (start_idx + i) & (vq_size - 1); n_buffers +=
> > +pkts_info[from].nr_buffers; pkts[i] = pkts_info[from].mbuf; } } else
> > +{ for (i = 0; i < n_pkts_put; i++) { from = (start_idx + i) &
> > +(vq_size - 1); n_descs += pkts_info[from].descs; pkts[i] =
> > +pkts_info[from].mbuf; }
> >  }
> > +
> >  vq->async_last_pkts_n = n_pkts_cpl - n_pkts_put;
> > vq->async_pkts_inflight_n -= n_pkts_put;
> >
> >  if (likely(vq->enabled && vq->access_ok)) { -uint16_t nr_left =
> > n_descs;  uint16_t nr_copy;  uint16_t to;
> >
> >  /* write back completed descriptors to used ring */ -do { -from =
> > vq->last_async_desc_idx & (vq->size - 1); -nr_copy = nr_left + from <=
> > vq->size ? nr_left :
> > -vq->size - from;
> > -to = vq->last_used_idx & (vq->size - 1);
> > -
> > -if (to + nr_copy <= vq->size) {
> > -rte_memcpy(&vq->used->ring[to],
> > +if (vq_is_packed(dev)) {
> > +uint16_t nr_left = n_buffers;
> > +uint16_t to;
> > +do {
> > +from = vq->last_async_buffer_idx &
> > +(vq->size - 1);
> > +to = (from + nr_left) & (vq->size - 1);
> > +
> > +if (to > from) {
> > +vhost_update_used_packed(dev, vq,
> > +vq->async_buffers_packed +
> > from,
> > +to - from);
> > +vq->last_async_buffer_idx += nr_left;
> > +nr_left = 0;
> > +} else {
> > +vhost_update_used_packed(dev, vq,
> > +vq->async_buffers_packed +
> > from,
> > +vq->size - from);
> > +vq->last_async_buffer_idx +=
> > +vq->size -
> > from;
> > +nr_left -= vq->size - from;
> > +}
> > +} while (nr_left > 0);
> > +vhost_vring_call_packed(dev, vq);
> > +} else {
> > +uint16_t nr_left = n_descs;
> > +do {
> > +from = vq->last_async_desc_idx & (vq->size -
> > 1);
> > +nr_copy = nr_left + from <= vq->size ? nr_left :
> > +vq->size - from;
> > +to = vq->last_used_idx & (vq->size - 1);
> > +
> > +if (to + nr_copy <= vq->size) {
> > +rte_memcpy(&vq->used->ring[to],
> >  &vq-
> > >async_descs_split[from],
> >  nr_copy *
> >  sizeof(struct
> > vring_used_elem));
> > -} else {
> > -uint16_t size = vq->size - to;
> > +} else {
> > +uint16_t size = vq->size - to;
> >
> > -rte_memcpy(&vq->used->ring[to],
> > +rte_memcpy(&vq->used->ring[to],
> >  &vq-
> > >async_descs_split[from],
> >  size *
> >  sizeof(struct
> > vring_used_elem));
> > -rte_memcpy(vq->used->ring,
> > +rte_memcpy(vq->used->ring,
> >  &vq->async_descs_split[from
> > +
> >  size], (nr_copy - size) *
> >  sizeof(struct
> > vring_used_elem));
> > -}
> > +}
> > +
> > +vq->last_async_desc_idx += nr_copy;
> > +vq->last_used_idx += nr_copy;
> > +nr_left -= nr_copy;
> > +} while (nr_left > 0);
> > +
> > +__atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
> > +vhost_vring_call_split(dev, vq); }
> >
> > -vq->last_async_desc_idx += nr_copy;
> > -vq->last_used_idx += nr_copy;
> > -nr_left -= nr_copy;
> > -} while (nr_left > 0);
> >
> > -__atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
> > -vhost_vring_call_split(dev, vq); -} else
> > -vq->last_async_desc_idx += n_descs;
> > +
> > +} else {
> > +if (vq_is_packed(dev))
> > +vq->last_async_buffer_idx += n_buffers;
> > +else
> > +vq->last_async_desc_idx += n_descs;
> > +}
> >
> >  done:
> >  rte_spinlock_unlock(&vq->access_lock);
> > @@ -1767,9 +2151,10 @@ virtio_dev_rx_async_submit(struct virtio_net
> > *dev, uint16_t queue_id,  if (count == 0)  goto out;
> >
> > -/* TODO: packed queue not implemented */  if (vq_is_packed(dev))
> > -nb_tx = 0;
> > +nb_tx = virtio_dev_rx_async_submit_packed(dev,
> > +vq, queue_id, pkts, count, comp_pkts, comp_count);
> >  else
> >  nb_tx = virtio_dev_rx_async_submit_split(dev,
> >  vq, queue_id, pkts, count, comp_pkts,
> > --
> > 2.29.2
>