From fe8477ebbd945cee1a322b348b52f9f276160efc Mon Sep 17 00:00:00 2001 From: Cheng Jiang Date: Mon, 13 Jun 2022 08:21:59 +0000 Subject: [PATCH] vhost: support async packed ring dequeue This patch implements packed ring dequeue data path for asynchronous vhost. Signed-off-by: Cheng Jiang Reviewed-by: Maxime Coquelin --- lib/vhost/virtio_net.c | 234 ++++++++++++++++++++++++++++++++++------- 1 file changed, 195 insertions(+), 39 deletions(-) diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index c939624ad9..229e6b32f4 100644 --- a/lib/vhost/virtio_net.c +++ b/lib/vhost/virtio_net.c @@ -27,7 +27,7 @@ #define MAX_BATCH_LEN 256 static __rte_always_inline uint16_t -async_poll_dequeue_completed_split(struct virtio_net *dev, struct vhost_virtqueue *vq, +async_poll_dequeue_completed(struct virtio_net *dev, struct vhost_virtqueue *vq, struct rte_mbuf **pkts, uint16_t count, int16_t dma_id, uint16_t vchan_id, bool legacy_ol_flags); @@ -2207,12 +2207,7 @@ rte_vhost_clear_queue_thread_unsafe(int vid, uint16_t queue_id, n_pkts_cpl = vhost_poll_enqueue_completed(dev, queue_id, pkts, count, dma_id, vchan_id); else { - if (unlikely(vq_is_packed(dev))) - VHOST_LOG_DATA(ERR, - "(%s) %s: async dequeue does not support packed ring.\n", - dev->ifname, __func__); - else - n_pkts_cpl = async_poll_dequeue_completed_split(dev, vq, pkts, count, + n_pkts_cpl = async_poll_dequeue_completed(dev, vq, pkts, count, dma_id, vchan_id, dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS); } @@ -2271,12 +2266,7 @@ rte_vhost_clear_queue(int vid, uint16_t queue_id, struct rte_mbuf **pkts, n_pkts_cpl = vhost_poll_enqueue_completed(dev, queue_id, pkts, count, dma_id, vchan_id); else { - if (unlikely(vq_is_packed(dev))) - VHOST_LOG_DATA(ERR, - "(%s) %s: async dequeue does not support packed ring.\n", - dev->ifname, __func__); - else - n_pkts_cpl = async_poll_dequeue_completed_split(dev, vq, pkts, count, + n_pkts_cpl = async_poll_dequeue_completed(dev, vq, pkts, count, dma_id, vchan_id, dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS); } @@ -3339,7 +3329,7 @@ out_access_unlock: } static __rte_always_inline uint16_t -async_poll_dequeue_completed_split(struct virtio_net *dev, struct vhost_virtqueue *vq, +async_poll_dequeue_completed(struct virtio_net *dev, struct vhost_virtqueue *vq, struct rte_mbuf **pkts, uint16_t count, int16_t dma_id, uint16_t vchan_id, bool legacy_ol_flags) { @@ -3354,7 +3344,7 @@ async_poll_dequeue_completed_split(struct virtio_net *dev, struct vhost_virtqueu from = start_idx; while (vq->async->pkts_cmpl_flag[from] && count--) { vq->async->pkts_cmpl_flag[from] = false; - from = (from + 1) & (vq->size - 1); + from = (from + 1) % vq->size; nr_cpl_pkts++; } @@ -3362,7 +3352,7 @@ async_poll_dequeue_completed_split(struct virtio_net *dev, struct vhost_virtqueu return 0; for (i = 0; i < nr_cpl_pkts; i++) { - from = (start_idx + i) & (vq->size - 1); + from = (start_idx + i) % vq->size; pkts[i] = pkts_info[from].mbuf; if (virtio_net_with_host_offload(dev)) @@ -3371,10 +3361,14 @@ async_poll_dequeue_completed_split(struct virtio_net *dev, struct vhost_virtqueu } /* write back completed descs to used ring and update used idx */ - write_back_completed_descs_split(vq, nr_cpl_pkts); - __atomic_add_fetch(&vq->used->idx, nr_cpl_pkts, __ATOMIC_RELEASE); - vhost_vring_call_split(dev, vq); - + if (vq_is_packed(dev)) { + write_back_completed_descs_packed(vq, nr_cpl_pkts); + vhost_vring_call_packed(dev, vq); + } else { + write_back_completed_descs_split(vq, nr_cpl_pkts); + __atomic_add_fetch(&vq->used->idx, nr_cpl_pkts, __ATOMIC_RELEASE); + vhost_vring_call_split(dev, vq); + } vq->async->pkts_inflight_n -= nr_cpl_pkts; return nr_cpl_pkts; @@ -3511,8 +3505,8 @@ virtio_dev_tx_async_split(struct virtio_net *dev, struct vhost_virtqueue *vq, out: /* DMA device may serve other queues, unconditionally check completed. */ - nr_done_pkts = async_poll_dequeue_completed_split(dev, vq, pkts, pkts_size, - dma_id, vchan_id, legacy_ol_flags); + nr_done_pkts = async_poll_dequeue_completed(dev, vq, pkts, pkts_size, + dma_id, vchan_id, legacy_ol_flags); return nr_done_pkts; } @@ -3539,6 +3533,171 @@ virtio_dev_tx_async_split_compliant(struct virtio_net *dev, pkts, count, dma_id, vchan_id, false); } +static __rte_always_inline void +vhost_async_shadow_dequeue_single_packed(struct vhost_virtqueue *vq, uint16_t buf_id) +{ + struct vhost_async *async = vq->async; + uint16_t idx = async->buffer_idx_packed; + + async->buffers_packed[idx].id = buf_id; + async->buffers_packed[idx].len = 0; + async->buffers_packed[idx].count = 1; + + async->buffer_idx_packed++; + if (async->buffer_idx_packed >= vq->size) + async->buffer_idx_packed -= vq->size; + +} + +static __rte_always_inline int +virtio_dev_tx_async_single_packed(struct virtio_net *dev, + struct vhost_virtqueue *vq, + struct rte_mempool *mbuf_pool, + struct rte_mbuf *pkts, + uint16_t slot_idx, + bool legacy_ol_flags) +{ + int err; + uint16_t buf_id, desc_count = 0; + uint16_t nr_vec = 0; + uint32_t buf_len; + struct buf_vector buf_vec[BUF_VECTOR_MAX]; + static bool allocerr_warned; + + if (unlikely(fill_vec_buf_packed(dev, vq, vq->last_avail_idx, &desc_count, + buf_vec, &nr_vec, &buf_id, &buf_len, + VHOST_ACCESS_RO) < 0)) + return -1; + + if (unlikely(virtio_dev_pktmbuf_prep(dev, pkts, buf_len))) { + if (!allocerr_warned) { + VHOST_LOG_DATA(ERR, "(%s) Failed mbuf alloc of size %d from %s.\n", + dev->ifname, buf_len, mbuf_pool->name); + + allocerr_warned = true; + } + return -1; + } + + err = desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkts, mbuf_pool, + legacy_ol_flags, slot_idx, true); + if (unlikely(err)) { + rte_pktmbuf_free(pkts); + if (!allocerr_warned) { + VHOST_LOG_DATA(ERR, "(%s) Failed to copy desc to mbuf on.\n", dev->ifname); + allocerr_warned = true; + } + return -1; + } + + /* update async shadow packed ring */ + vhost_async_shadow_dequeue_single_packed(vq, buf_id); + + return err; +} + +static __rte_always_inline uint16_t +virtio_dev_tx_async_packed(struct virtio_net *dev, struct vhost_virtqueue *vq, + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, + uint16_t count, uint16_t dma_id, uint16_t vchan_id, bool legacy_ol_flags) +{ + uint16_t pkt_idx; + uint16_t slot_idx = 0; + uint16_t nr_done_pkts = 0; + uint16_t pkt_err = 0; + uint32_t n_xfer; + struct vhost_async *async = vq->async; + struct async_inflight_info *pkts_info = async->pkts_info; + struct rte_mbuf *pkts_prealloc[MAX_PKT_BURST]; + + VHOST_LOG_DATA(DEBUG, "(%d) about to dequeue %u buffers\n", dev->vid, count); + + async_iter_reset(async); + + if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts_prealloc, count)) + goto out; + + for (pkt_idx = 0; pkt_idx < count; pkt_idx++) { + struct rte_mbuf *pkt = pkts_prealloc[pkt_idx]; + + rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]); + + slot_idx = (async->pkts_idx + pkt_idx) % vq->size; + if (unlikely(virtio_dev_tx_async_single_packed(dev, vq, mbuf_pool, pkt, + slot_idx, legacy_ol_flags))) { + rte_pktmbuf_free_bulk(&pkts_prealloc[pkt_idx], count - pkt_idx); + break; + } + + pkts_info[slot_idx].mbuf = pkt; + + vq_inc_last_avail_packed(vq, 1); + + } + + n_xfer = vhost_async_dma_transfer(dev, vq, dma_id, vchan_id, async->pkts_idx, + async->iov_iter, pkt_idx); + + async->pkts_inflight_n += n_xfer; + + pkt_err = pkt_idx - n_xfer; + + if (unlikely(pkt_err)) { + pkt_idx -= pkt_err; + + /** + * recover DMA-copy related structures and free pktmbuf for DMA-error pkts. + */ + if (async->buffer_idx_packed >= pkt_err) + async->buffer_idx_packed -= pkt_err; + else + async->buffer_idx_packed += vq->size - pkt_err; + + while (pkt_err-- > 0) { + rte_pktmbuf_free(pkts_info[slot_idx % vq->size].mbuf); + slot_idx--; + } + + /* recover available ring */ + if (vq->last_avail_idx >= pkt_err) { + vq->last_avail_idx -= pkt_err; + } else { + vq->last_avail_idx += vq->size - pkt_err; + vq->avail_wrap_counter ^= 1; + } + } + + async->pkts_idx += pkt_idx; + if (async->pkts_idx >= vq->size) + async->pkts_idx -= vq->size; + +out: + nr_done_pkts = async_poll_dequeue_completed(dev, vq, pkts, count, + dma_id, vchan_id, legacy_ol_flags); + + return nr_done_pkts; +} + +__rte_noinline +static uint16_t +virtio_dev_tx_async_packed_legacy(struct virtio_net *dev, struct vhost_virtqueue *vq, + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, + uint16_t count, uint16_t dma_id, uint16_t vchan_id) +{ + return virtio_dev_tx_async_packed(dev, vq, mbuf_pool, + pkts, count, dma_id, vchan_id, true); +} + +__rte_noinline +static uint16_t +virtio_dev_tx_async_packed_compliant(struct virtio_net *dev, struct vhost_virtqueue *vq, + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, + uint16_t count, uint16_t dma_id, uint16_t vchan_id) +{ + return virtio_dev_tx_async_packed(dev, vq, mbuf_pool, + pkts, count, dma_id, vchan_id, false); +} + uint16_t rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id, struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count, @@ -3641,25 +3800,22 @@ rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id, count -= 1; } - if (unlikely(vq_is_packed(dev))) { - static bool not_support_pack_log; - if (!not_support_pack_log) { - VHOST_LOG_DATA(ERR, - "(%s) %s: async dequeue does not support packed ring.\n", - dev->ifname, __func__); - not_support_pack_log = true; - } - count = 0; - goto out; + if (vq_is_packed(dev)) { + if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS) + count = virtio_dev_tx_async_packed_legacy(dev, vq, mbuf_pool, + pkts, count, dma_id, vchan_id); + else + count = virtio_dev_tx_async_packed_compliant(dev, vq, mbuf_pool, + pkts, count, dma_id, vchan_id); + } else { + if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS) + count = virtio_dev_tx_async_split_legacy(dev, vq, mbuf_pool, + pkts, count, dma_id, vchan_id); + else + count = virtio_dev_tx_async_split_compliant(dev, vq, mbuf_pool, + pkts, count, dma_id, vchan_id); } - if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS) - count = virtio_dev_tx_async_split_legacy(dev, vq, mbuf_pool, pkts, - count, dma_id, vchan_id); - else - count = virtio_dev_tx_async_split_compliant(dev, vq, mbuf_pool, pkts, - count, dma_id, vchan_id); - *nr_inflight = vq->async->pkts_inflight_n; out: -- 2.39.5