[dpdk-dev] [PATCH v5 2/4] vhost: add support for packed ring in async vhost
Jiang, Cheng1
cheng1.jiang at intel.com
Tue Apr 13 13:48:25 CEST 2021
Hi Maxime,
> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin at redhat.com>
> Sent: Tuesday, April 13, 2021 4:37 PM
> To: Jiang, Cheng1 <cheng1.jiang at intel.com>; Xia, Chenbo
> <chenbo.xia at intel.com>
> Cc: dev at dpdk.org; Hu, Jiayu <jiayu.hu at intel.com>; Yang, YvonneX
> <yvonnex.yang at intel.com>; Wang, Yinan <yinan.wang at intel.com>; Liu,
> Yong <yong.liu at intel.com>
> Subject: Re: [PATCH v5 2/4] vhost: add support for packed ring in async vhost
>
>
>
> On 4/12/21 1:34 PM, Cheng Jiang wrote:
> > 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 at intel.com>
> > ---
> > lib/librte_vhost/rte_vhost_async.h | 1 +
> > lib/librte_vhost/vhost.c | 27 +-
> > lib/librte_vhost/vhost.h | 7 +-
> > lib/librte_vhost/virtio_net.c | 438 +++++++++++++++++++++++++++--
> > 4 files changed, 448 insertions(+), 25 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
> > a70fe01d8..8c9935c0f 100644
> > --- a/lib/librte_vhost/vhost.c
> > +++ b/lib/librte_vhost/vhost.c
> > @@ -342,15 +342,21 @@ 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;
> > + }
> > + if (vq->async_descs_split) {
>
> You can remove the check, rte_free is safe with NULL pointers.
> You can do the same for the other ones in this function.
OK, it will be fixed.
>
> > 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;
> > }
> > @@ -1627,9 +1633,9 @@ 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;
> > }
> > @@ -1667,11 +1673,18 @@ 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,
> > + vq->size * 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 ||
> > - !vq->it_pool || !vq->vec_pool) {
> > + }
> > +
> > + if (!vq->async_buffers_packed || !vq->async_descs_split ||
> > + !vq->async_pkts_info || !vq->it_pool || !vq->vec_pool) {
> > vhost_free_async_mem(vq);
> > VHOST_LOG_CONFIG(ERR,
> > "async register failed: cannot allocate
> memory for vq data "
> > diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> > f628714c2..fe131ae8f 100644
> > --- a/lib/librte_vhost/vhost.h
> > +++ b/lib/librte_vhost/vhost.h
> > @@ -201,9 +201,14 @@ struct vhost_virtqueue {
> > uint16_t async_pkts_idx;
> > uint16_t async_pkts_inflight_n;
> > uint16_t async_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;
>
> Don't dupplicate variable names, async_desc_idx can be reused for packed
> ring. Also, they are representing the same thing, why use desc in one case
> and buffer in the other?
The main reason is that the unit of the packed used ring is buffer, which can contain many desc.
I think using desc_idx will cause ambiguity, but if you think that I should reuse the desc_idx, I have no problem with that.
>
> > uint16_t last_async_desc_idx;
> > + uint16_t last_async_buffer_idx;
>
> Same remark here.
>
> > /* vq async features */
> > bool async_inorder;
> > diff --git a/lib/librte_vhost/virtio_net.c
> > b/lib/librte_vhost/virtio_net.c index c43ab0093..410be9678 100644
> > --- a/lib/librte_vhost/virtio_net.c
> > +++ b/lib/librte_vhost/virtio_net.c
> > @@ -363,14 +363,14 @@
> > 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,
> > - uint32_t len[],
> > - uint16_t id[],
> > - uint16_t count[],
> > +vhost_shadow_enqueue_packed(struct vhost_virtqueue *vq,
> > + uint32_t *len,
> > + uint16_t *id,
> > + uint16_t *count,
> > uint16_t num_buffers)
> > {
> > uint16_t i;
> > +
> > for (i = 0; i < num_buffers; i++) {
> > /* enqueue shadow flush action aligned with batch num */
> > if (!vq->shadow_used_idx)
> > @@ -382,6 +382,17 @@ 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);
> > @@ -1481,6 +1492,62 @@ shadow_ring_store(struct vhost_virtqueue *vq,
> void *shadow_ring, void *d_ring,
> > }
> > }
> >
> > +static __rte_always_inline void
> > +vhost_update_used_packed(struct vhost_virtqueue *vq,
> > + struct vring_used_elem_packed *shadow_ring,
> > + uint16_t count)
> > +{
> > + if (count == 0)
> > + return;
>
> Move this after the variables declaration.
Sure.
>
> > +
> > + 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;
> > +
> > + } 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; }
> > +
> > static __rte_noinline uint32_t
> > virtio_dev_rx_async_submit_split(struct virtio_net *dev,
> > struct vhost_virtqueue *vq, uint16_t queue_id, @@ -1656,6
> +1723,294
> > @@ 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 vring_packed_desc *async_descs,
> > + 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 = 0;
> > + 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;
> > + /* store descriptors for DMA */
> > + if (avail_idx >= *nr_descs)
> > + rte_memcpy(async_descs,
> > + &vq->desc_packed[vq->last_avail_idx],
> > + *nr_descs * sizeof(struct vring_packed_desc));
>
> Please add brackets for the 'if' since there are for the 'else'.
Sure, sorry for that.
>
> > + else {
> > + uint16_t nr_copy = vq->size - vq->last_avail_idx;
> > + rte_memcpy(async_descs,
> > + &vq->desc_packed[vq->last_avail_idx],
> > + nr_copy * sizeof(struct vring_packed_desc));
> > + rte_memcpy(async_descs + nr_copy,
> > + vq->desc_packed, (*nr_descs - nr_copy) *
> > + sizeof(struct vring_packed_desc));
> > + }
> > +
> > + 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 vring_packed_desc *async_descs,
> > + 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,
> > + async_descs,
> > + 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) {
> > + uint32_t pkt_idx = 0, pkt_burst_idx = 0;
> > + uint16_t async_descs_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;
> > + uint16_t iovec_idx = 0, it_idx = 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 vring_packed_desc async_descs[vq->size];
> > +
> > + rte_prefetch0(&vq->desc_packed[vq->last_avail_idx & (vq->size -
> > +1)]);
>
> The size of the ring is not necessarily a power of two with packed ring.
For the size of the ring is not necessarily a power of two,
so maybe I can use codes like
Indx % vq->size ?
I'm not sure if it's a good way to do that.
>
> > +
> > + 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,
> > +
> &async_descs[async_descs_idx],
> > + &src_iovec[iovec_idx],
> > + &dst_iovec[iovec_idx],
> > + &src_it[it_idx],
> > + &dst_it[it_idx]) < 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);
>
> Same here.
Sure.
>
> > + if (src_it[it_idx].count) {
> > + uint16_t from, to;
> > +
> > + async_descs_idx += num_desc;
> > + async_fill_desc(&tdes[pkt_burst_idx++],
> &src_it[it_idx],
> > + &dst_it[it_idx]);
> > + pkts_info[slot_idx].descs = num_desc;
> > + pkts_info[slot_idx].nr_buffers = num_buffers;
> > + pkts_info[slot_idx].mbuf = pkts[pkt_idx];
> > + num_async_pkts++;
> > + iovec_idx += src_it[it_idx].nr_segs;
> > + it_idx += 2;
> > +
> > + segs_await += src_it[it_idx].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);
> > + shadow_ring_store(vq, vq->shadow_used_packed,
> > + vq->async_buffers_packed,
> > + from, to, num_buffers,
> > + sizeof(struct
> vring_used_elem_packed));
> > +
> > + vq->async_packed_buffer_idx += num_buffers;
> > + vq->shadow_used_idx -= num_buffers;
> > + } else
>
> Brackets needed.
Sure.
>
> > + 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);
> > + iovec_idx = 0;
> > + it_idx = 0;
> > + 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;
> > + pkt_idx++;
> > + 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 descs_err = 0;
> > + uint16_t buffers_err = 0;
> > +
> > + num_async_pkts -= pkt_err;
> > + pkt_idx -= pkt_err;
> > + /* calculate the sum of buffers and descs of DMA-error packets. */
> > + while (pkt_err-- > 0) {
> > + descs_err +=
> > + pkts_info[slot_idx & (vq->size - 1)].descs;
>
> The size of the ring is not necessarily a power of two with packed ring.
Will be fixed.
>
> > + buffers_err +=
> > + pkts_info[slot_idx & (vq->size -
> 1)].nr_buffers;
>
> Ditto.
Will be fixed.
>
> > + slot_idx--;
> > + }
> > +
> > + vq->async_packed_buffer_idx -= buffers_err;
> > +
> > + if (vq->last_avail_idx >= descs_err) {
> > + vq->last_avail_idx -= descs_err;
> > +
> > + rte_memcpy(&vq->desc_packed[vq->last_avail_idx],
> > + &async_descs[async_descs_idx - descs_err],
> > + descs_err * sizeof(struct
> vring_packed_desc));
> > + } else {
> > + uint16_t nr_copy;
> > +
> > + vq->last_avail_idx = vq->last_avail_idx + vq->size
> > + - descs_err;
> > + nr_copy = vq->size - vq->last_avail_idx;
> > + rte_memcpy(&vq->desc_packed[vq->last_avail_idx],
> > + &async_descs[async_descs_idx - descs_err],
> > + nr_copy * sizeof(struct vring_packed_desc));
> > + descs_err -= nr_copy;
> > + rte_memcpy(vq->desc_packed,
> > + &async_descs[async_descs_idx - descs_err],
> > + descs_err * sizeof(struct
> vring_packed_desc));
> > + vq->avail_wrap_counter ^= 1;
> > + }
> > +
> > + num_done_pkts = pkt_idx - num_async_pkts;
> > + }
>
> This error handling could be moved in a dedicated function.
Sure, will fix it in the next version.
>
> > + 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;
> > +}
>
> Above function is very big and complex, it should be possible to split it in
> several ones to make it maintainable.
I think move the error handling code will make it smaller.
Thanks.
Cheng
>
> > +
> > static __rte_always_inline void
> > write_back_completed_descs_split(struct vhost_virtqueue *vq, uint16_t
> > n_descs) { @@ -1693,12 +2048,40 @@
> > write_back_completed_descs_split(struct vhost_virtqueue *vq, uint16_t
> n_descs)
> > } while (nr_left > 0);
> > }
> >
> > +static __rte_always_inline void
> > +write_back_completed_descs_packed(struct vhost_virtqueue *vq,
> > + uint16_t n_buffers)
> > +{
> > + uint16_t nr_left = n_buffers;
> > + uint16_t from, to;
> > +
> > + do {
> > + from = vq->last_async_buffer_idx &
> > + (vq->size - 1);
> > + to = (from + nr_left) & (vq->size - 1);
>
> The size of the ring is not necessarily a power of two with packed ring.
Sure.
>
> > + if (to > from) {
> > + vhost_update_used_packed(vq,
> > + vq->async_buffers_packed + from,
> > + to - from);
> > + vq->last_async_buffer_idx += nr_left;
> > + nr_left = 0;
> > + } else {
> > + vhost_update_used_packed(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);
> > +}
> > +
> > 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;
> > @@ -1740,21 +2123,41 @@ 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);
>
> Unlike split ring, packed ring size is not necessarily a power of 2.
Sure.
Thanks.
>
> > + 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)) {
> > - write_back_completed_descs_split(vq, n_descs);
> > + if (vq_is_packed(dev)) {
> > + write_back_completed_descs_packed(vq,
> n_buffers);
> >
> > - __atomic_add_fetch(&vq->used->idx, n_descs,
> __ATOMIC_RELEASE);
> > - vhost_vring_call_split(dev, vq);
> > - } else
> > - vq->last_async_desc_idx += n_descs;
> > + vhost_vring_call_packed(dev, vq);
> > + } else {
> > + write_back_completed_descs_split(vq, n_descs);
> > +
> > + __atomic_add_fetch(&vq->used->idx, n_descs,
> > + __ATOMIC_RELEASE);
> > + vhost_vring_call_split(dev, vq);
> > + }
> > + } 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);
> > @@ -1795,9 +2198,10 @@ 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,
> >
More information about the dev
mailing list