Hi Cheng,
> -----Original Message-----
> From: Jiang, Cheng1 <cheng1.ji...@intel.com>
> Sent: Wednesday, April 14, 2021 2:14 PM
> To: maxime.coque...@redhat.com; Xia, Chenbo <chenbo....@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu...@intel.com>; Yang, YvonneX
> <yvonnex.y...@intel.com>; Wang, Yinan <yinan.w...@intel.com>; Liu,
> Yong <yong....@intel.com>; Jiang, Cheng1 <cheng1.ji...@intel.com>
> Subject: [PATCH v7 2/4] vhost: add support for packed ring in async vhost
>
> For now async vhost data path only supports split ring. This patch
> enables packed ring in async vhost data path to make async vhost
> compatible with virtio 1.1 spec.
>
> Signed-off-by: Cheng Jiang <cheng1.ji...@intel.com>
> ---
> lib/librte_vhost/rte_vhost_async.h | 1 +
> lib/librte_vhost/vhost.c | 49 ++--
> lib/librte_vhost/vhost.h | 15 +-
> lib/librte_vhost/virtio_net.c | 432 +++++++++++++++++++++++++++--
> 4 files changed, 456 insertions(+), 41 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..f509186c6 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -338,19 +338,22 @@ cleanup_device(struct virtio_net *dev, int destroy)
> }
>
> static void
> -vhost_free_async_mem(struct vhost_virtqueue *vq)
> +vhost_free_async_mem(struct virtio_net *dev, struct vhost_virtqueue *vq)
> {
> - if (vq->async_pkts_info)
> - rte_free(vq->async_pkts_info);
> - if (vq->async_descs_split)
> + rte_free(vq->async_pkts_info);
> +
> + if (vq_is_packed(dev)) {
> + rte_free(vq->async_buffers_packed);
> + vq->async_buffers_packed = NULL;
> + } else {
> rte_free(vq->async_descs_split);
> - if (vq->it_pool)
> - rte_free(vq->it_pool);
> - if (vq->vec_pool)
> - rte_free(vq->vec_pool);
> + vq->async_descs_split = NULL;
> + }
> +
> + rte_free(vq->it_pool);
> + rte_free(vq->vec_pool);
>
> vq->async_pkts_info = NULL;
> - vq->async_descs_split = NULL;
> vq->it_pool = NULL;
> vq->vec_pool = NULL;
> }
> @@ -360,10 +363,10 @@ free_vq(struct virtio_net *dev, struct
> vhost_virtqueue *vq)
> {
> if (vq_is_packed(dev))
> rte_free(vq->shadow_used_packed);
> - else {
> + else
> rte_free(vq->shadow_used_split);
> - vhost_free_async_mem(vq);
> - }
> +
> + vhost_free_async_mem(dev, vq);
> rte_free(vq->batch_copy_elems);
> if (vq->iotlb_pool)
> rte_mempool_free(vq->iotlb_pool);
> @@ -1626,10 +1629,9 @@ int rte_vhost_async_channel_register(int vid,
> uint16_t queue_id,
> if (unlikely(vq == NULL || !dev->async_copy))
> 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;
> }
> @@ -1667,12 +1669,19 @@ 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) {
> - vhost_free_async_mem(vq);
> + }
> +
> + if (!vq->async_buffers_packed || !vq->async_descs_split ||
async_buffers_packed and async_descs_split are two members of a union.
Like the way processed in vhost_free_async_mem(), do you think it's better
to check if they are NULL in if-else respectively?
> + !vq->async_pkts_info || !vq->it_pool || !vq->vec_pool) {
> + vhost_free_async_mem(dev, vq);
> VHOST_LOG_CONFIG(ERR,
> "async register failed: cannot allocate
> memory for vq data "
> "(vid %d, qid: %d)\n", vid, queue_id);
> @@ -1728,7 +1737,7 @@ int rte_vhost_async_channel_unregister(int vid,
> uint16_t queue_id)
> goto out;
> }
>
> - vhost_free_async_mem(vq);
> + vhost_free_async_mem(dev, vq);
>
> vq->async_ops.transfer_data = NULL;
> vq->async_ops.check_completed_copies = NULL;
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index f628714c2..673335217 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -201,9 +201,18 @@ 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;
> - uint16_t async_desc_idx;
> - uint16_t last_async_desc_idx;
> + union {
> + struct vring_used_elem *async_descs_split;
> + struct vring_used_elem_packed *async_buffers_packed;
> + };
> + union {
> + uint16_t async_desc_idx;
> + uint16_t async_packed_buffer_idx;
> + };
> + union {
> + uint16_t last_async_desc_idx;
> + uint16_t last_async_buffer_idx;
> + };
>
> /* vq async features */
> bool async_inorder;
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index 438bdafd1..54e11e3a5 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);
> @@ -1474,6 +1485,23 @@ store_dma_desc_info_split(struct
> vring_used_elem *s_ring, struct vring_used_elem
> }
> }
>
> +static __rte_always_inline void
> +store_dma_desc_info_packed(struct vring_used_elem_packed *s_ring,
> + struct vring_used_elem_packed *d_ring,
> + uint16_t ring_size, uint16_t s_idx, uint16_t d_idx, uint16_t
> count)
> +{
> + uint16_t elem_size = sizeof(struct vring_used_elem_packed);
> +
> + if (d_idx + count <= ring_size) {
> + rte_memcpy(d_ring + d_idx, s_ring + s_idx, count *
> elem_size);
> + } else {
> + uint16_t size = ring_size - d_idx;
> +
> + rte_memcpy(d_ring + d_idx, s_ring + s_idx, size * elem_size);
> + rte_memcpy(d_ring, s_ring + s_idx + size, (count - size) *
> elem_size);
> + }
> +}
> +
> static __rte_noinline uint32_t
> virtio_dev_rx_async_submit_split(struct virtio_net *dev,
> struct vhost_virtqueue *vq, uint16_t queue_id,
> @@ -1641,6 +1669,330 @@ virtio_dev_rx_async_submit_split(struct
> virtio_net *dev,
> return pkt_idx;
> }
>
> +static __rte_always_inline void
> +vhost_update_used_packed(struct vhost_virtqueue *vq,
> + struct vring_used_elem_packed *shadow_ring,
> + uint16_t count)
> +{
> + int i;
> + uint16_t used_idx = vq->last_used_idx;
> + uint16_t head_idx = vq->last_used_idx;
> + uint16_t head_flags = 0;
> +
> + if (count == 0)
> + return;
> +
> + /* 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;
> +
No need a blank line above.
> + } 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_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));
> + } 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_always_inline void
> +dma_error_handler_packed(struct vhost_virtqueue *vq, struct
> vring_packed_desc *async_descs,
> + uint16_t async_descs_idx, uint16_t slot_idx, uint32_t
> nr_err,
> + uint32_t *pkt_idx, uint32_t *num_async_pkts,
> uint32_t *num_done_pkts)
> +{
> + uint16_t descs_err = 0;
> + uint16_t buffers_err = 0;
> + struct async_inflight_info *pkts_info = vq->async_pkts_info;
> +
> + *num_async_pkts -= nr_err;
> + *pkt_idx -= nr_err;
> + /* calculate the sum of buffers and descs of DMA-error packets. */
> + while (nr_err-- > 0) {
> + descs_err += pkts_info[slot_idx % vq->size].descs;
I notice there are several parts using "%" to wrap around index, but
existed code uses "& (vq->size - 1)" instead. I think it's better to keep
it consistent.
Thanks,
Jiayu
