From a3cfa8081f65339b356591036ed25a510098a901 Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Tue, 26 Oct 2021 18:28:59 +0200 Subject: [PATCH] vhost: simplify async enqueue completion vhost_poll_enqueue_completed() assumes some inflight packets could have been completed in a previous call but not returned to the application. But this is not the case, since check_completed_copies callback is never called with more than the current count as argument. In other words, async->last_pkts_n is always 0. Removing it greatly simplifies the function. Signed-off-by: Maxime Coquelin Reviewed-by: Jiayu Hu --- lib/vhost/vhost.h | 1 - lib/vhost/virtio_net.c | 76 ++++++++++++++++-------------------------- 2 files changed, 28 insertions(+), 49 deletions(-) diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h index 1e3f1bad91..1ba9a60ef2 100644 --- a/lib/vhost/vhost.h +++ b/lib/vhost/vhost.h @@ -141,7 +141,6 @@ struct vhost_async { struct async_inflight_info *pkts_info; uint16_t pkts_idx; uint16_t pkts_inflight_n; - uint16_t last_pkts_n; union { struct vring_used_elem *descs_split; struct vring_used_elem_packed *buffers_packed; diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index dfe864b3e9..3206b3f816 100644 --- a/lib/vhost/virtio_net.c +++ b/lib/vhost/virtio_net.c @@ -1619,7 +1619,11 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev, vq->shadow_used_idx); async->desc_idx_split += vq->shadow_used_idx; + async->pkts_idx += pkt_idx; + if (async->pkts_idx >= vq->size) + async->pkts_idx -= vq->size; + async->pkts_inflight_n += pkt_idx; vq->shadow_used_idx = 0; } @@ -1921,68 +1925,44 @@ static __rte_always_inline uint16_t vhost_poll_enqueue_completed(struct virtio_net *dev, uint16_t queue_id, struct rte_mbuf **pkts, uint16_t count) { - struct vhost_virtqueue *vq; - struct vhost_async *async; - struct async_inflight_info *pkts_info; + struct vhost_virtqueue *vq = dev->virtqueue[queue_id]; + struct vhost_async *async = vq->async; + struct async_inflight_info *pkts_info = async->pkts_info; int32_t n_cpl; - uint16_t n_pkts_cpl = 0, n_pkts_put = 0, n_descs = 0, n_buffers = 0; - uint16_t start_idx, pkts_idx, vq_size; - uint16_t from, i; + uint16_t n_descs = 0, n_buffers = 0; + uint16_t start_idx, from, i; - vq = dev->virtqueue[queue_id]; - async = vq->async; - pkts_idx = async->pkts_idx % vq->size; - pkts_info = async->pkts_info; - vq_size = vq->size; - start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx, - vq_size, async->pkts_inflight_n); - - if (count > async->last_pkts_n) { - n_cpl = async->ops.check_completed_copies(dev->vid, - queue_id, 0, count - async->last_pkts_n); - if (likely(n_cpl >= 0)) { - n_pkts_cpl = n_cpl; - } else { - VHOST_LOG_DATA(ERR, - "(%d) %s: failed to check completed copies for queue id %d.\n", + start_idx = virtio_dev_rx_async_get_info_idx(async->pkts_idx, + vq->size, async->pkts_inflight_n); + + n_cpl = async->ops.check_completed_copies(dev->vid, queue_id, 0, count); + if (unlikely(n_cpl < 0)) { + VHOST_LOG_DATA(ERR, "(%d) %s: failed to check completed copies for queue id %d.\n", dev->vid, __func__, queue_id); - n_pkts_cpl = 0; - } + return 0; } - n_pkts_cpl += async->last_pkts_n; - n_pkts_put = RTE_MIN(n_pkts_cpl, count); - if (unlikely(n_pkts_put == 0)) { - async->last_pkts_n = n_pkts_cpl; + if (n_cpl == 0) return 0; - } - if (vq_is_packed(dev)) { - for (i = 0; i < n_pkts_put; i++) { - from = (start_idx + i) % vq_size; - 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; - } + for (i = 0; i < n_cpl; i++) { + from = (start_idx + i) % vq->size; + /* Only used with packed ring */ + n_buffers += pkts_info[from].nr_buffers; + /* Only used with split ring */ + n_descs += pkts_info[from].descs; + pkts[i] = pkts_info[from].mbuf; } - async->last_pkts_n = n_pkts_cpl - n_pkts_put; - async->pkts_inflight_n -= n_pkts_put; + + async->pkts_inflight_n -= n_cpl; if (likely(vq->enabled && vq->access_ok)) { if (vq_is_packed(dev)) { write_back_completed_descs_packed(vq, n_buffers); - 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); + __atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE); vhost_vring_call_split(dev, vq); } } else { @@ -1995,7 +1975,7 @@ vhost_poll_enqueue_completed(struct virtio_net *dev, uint16_t queue_id, } } - return n_pkts_put; + return n_cpl; } uint16_t -- 2.39.5