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From: Chenbo Xia <chenbox@nvidia.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
	"david.marchand@redhat.com" <david.marchand@redhat.com>
Subject: Re: [PATCH v3 2/3] vhost: rework dequeue paths error handling
Date: Thu, 16 Jan 2025 12:15:13 +0000	[thread overview]
Message-ID: <C0006886-54DD-4B1E-9877-E0A173537F44@nvidia.com> (raw)
In-Reply-To: <20250116095416.3655699-3-maxime.coquelin@redhat.com>



> On Jan 16, 2025, at 17:54, Maxime Coquelin <maxime.coquelin@redhat.com> wrote:
> 
> External email: Use caution opening links or attachments
> 
> 
> This patch refactors the error handling in the Vhost
> dequeue paths to ease its maintenance and readability.
> 
> Suggested-by: David Marchand <david.marchand@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
> lib/vhost/virtio_net.c | 58 +++++++++++++++++++-----------------------
> 1 file changed, 26 insertions(+), 32 deletions(-)
> 
> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
> index a340e5a772..59ea2d16a5 100644
> --- a/lib/vhost/virtio_net.c
> +++ b/lib/vhost/virtio_net.c
> @@ -3593,6 +3593,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
>        struct rte_mbuf *rarp_mbuf = NULL;
>        struct vhost_virtqueue *vq;
>        int16_t success = 1;
> +       uint16_t nb_rx = 0;
> 
>        dev = get_device(vid);
>        if (!dev)
> @@ -3602,25 +3603,23 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
>                VHOST_DATA_LOG(dev->ifname, ERR,
>                        "%s: built-in vhost net backend is disabled.",
>                        __func__);
> -               return 0;
> +               goto out_no_unlock;
>        }
> 
>        if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
>                VHOST_DATA_LOG(dev->ifname, ERR,
>                        "%s: invalid virtqueue idx %d.",
>                        __func__, queue_id);
> -               return 0;
> +               goto out_no_unlock;
>        }
> 
>        vq = dev->virtqueue[queue_id];
> 
>        if (unlikely(rte_rwlock_read_trylock(&vq->access_lock) != 0))
> -               return 0;
> +               goto out_no_unlock;
> 
> -       if (unlikely(!vq->enabled)) {
> -               count = 0;
> +       if (unlikely(!vq->enabled))
>                goto out_access_unlock;
> -       }
> 
>        vhost_user_iotlb_rd_lock(vq);
> 
> @@ -3630,7 +3629,6 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
> 
>                virtio_dev_vring_translate(dev, vq);
> 
> -               count = 0;
>                goto out_no_unlock;
>        }
> 
> @@ -3657,7 +3655,6 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
>                rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
>                if (rarp_mbuf == NULL) {
>                        VHOST_DATA_LOG(dev->ifname, ERR, "failed to make RARP packet.");
> -                       count = 0;
>                        goto out;
>                }
>                /*
> @@ -3672,17 +3669,17 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
> 
>        if (vq_is_packed(dev)) {
>                if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
> -                       count = virtio_dev_tx_packed_legacy(dev, vq, mbuf_pool, pkts, count);
> +                       nb_rx = virtio_dev_tx_packed_legacy(dev, vq, mbuf_pool, pkts, count);
>                else
> -                       count = virtio_dev_tx_packed_compliant(dev, vq, mbuf_pool, pkts, count);
> +                       nb_rx = virtio_dev_tx_packed_compliant(dev, vq, mbuf_pool, pkts, count);
>        } else {
>                if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
> -                       count = virtio_dev_tx_split_legacy(dev, vq, mbuf_pool, pkts, count);
> +                       nb_rx = virtio_dev_tx_split_legacy(dev, vq, mbuf_pool, pkts, count);
>                else
> -                       count = virtio_dev_tx_split_compliant(dev, vq, mbuf_pool, pkts, count);
> +                       nb_rx = virtio_dev_tx_split_compliant(dev, vq, mbuf_pool, pkts, count);
>        }
> 
> -       vhost_queue_stats_update(dev, vq, pkts, count);
> +       vhost_queue_stats_update(dev, vq, pkts, nb_rx);
> 
> out:
>        vhost_user_iotlb_rd_unlock(vq);
> @@ -3691,10 +3688,10 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
>        rte_rwlock_read_unlock(&vq->access_lock);
> 
>        if (unlikely(rarp_mbuf != NULL))
> -               count += 1;
> +               nb_rx += 1;
> 
> out_no_unlock:
> -       return count;
> +       return nb_rx;
> }
> 
> static __rte_always_inline uint16_t
> @@ -4200,52 +4197,51 @@ rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
>        struct rte_mbuf *rarp_mbuf = NULL;
>        struct vhost_virtqueue *vq;
>        int16_t success = 1;
> +       uint16_t nb_rx = 0;
> 
>        dev = get_device(vid);
>        if (!dev || !nr_inflight)
> -               return 0;
> +               goto out_no_unlock;
> 
>        *nr_inflight = -1;
> 
>        if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
>                VHOST_DATA_LOG(dev->ifname, ERR, "%s: built-in vhost net backend is disabled.",
>                        __func__);
> -               return 0;
> +               goto out_no_unlock;
>        }
> 
>        if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
>                VHOST_DATA_LOG(dev->ifname, ERR, "%s: invalid virtqueue idx %d.",
>                        __func__, queue_id);
> -               return 0;
> +               goto out_no_unlock;
>        }
> 
>        if (unlikely(dma_id < 0 || dma_id >= RTE_DMADEV_DEFAULT_MAX)) {
>                VHOST_DATA_LOG(dev->ifname, ERR, "%s: invalid dma id %d.",
>                        __func__, dma_id);
> -               return 0;
> +               goto out_no_unlock;
>        }
> 
>        if (unlikely(!dma_copy_track[dma_id].vchans ||
>                                !dma_copy_track[dma_id].vchans[vchan_id].pkts_cmpl_flag_addr)) {
>                VHOST_DATA_LOG(dev->ifname, ERR, "%s: invalid channel %d:%u.",
>                        __func__, dma_id, vchan_id);
> -               return 0;
> +               goto out_no_unlock;
>        }
> 
>        vq = dev->virtqueue[queue_id];
> 
>        if (unlikely(rte_rwlock_read_trylock(&vq->access_lock) != 0))
> -               return 0;
> +               goto out_no_unlock;
> 
>        if (unlikely(vq->enabled == 0)) {
> -               count = 0;
>                goto out_access_unlock;
>        }
> 
>        if (unlikely(!vq->async)) {
>                VHOST_DATA_LOG(dev->ifname, ERR, "%s: async not registered for queue id %d.",
>                        __func__, queue_id);
> -               count = 0;
>                goto out_access_unlock;
>        }
> 
> @@ -4256,7 +4252,6 @@ rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
>                rte_rwlock_read_unlock(&vq->access_lock);
> 
>                virtio_dev_vring_translate(dev, vq);
> -               count = 0;
>                goto out_no_unlock;
>        }
> 
> @@ -4283,7 +4278,6 @@ rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
>                rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
>                if (rarp_mbuf == NULL) {
>                        VHOST_DATA_LOG(dev->ifname, ERR, "failed to make RARP packet.");
> -                       count = 0;
>                        goto out;
>                }
>                /*
> @@ -4298,22 +4292,22 @@ rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
> 
>        if (vq_is_packed(dev)) {
>                if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
> -                       count = virtio_dev_tx_async_packed_legacy(dev, vq, mbuf_pool,
> +                       nb_rx = 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,
> +                       nb_rx = 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,
> +                       nb_rx = 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,
> +                       nb_rx = virtio_dev_tx_async_split_compliant(dev, vq, mbuf_pool,
>                                        pkts, count, dma_id, vchan_id);
>        }
> 
>        *nr_inflight = vq->async->pkts_inflight_n;
> -       vhost_queue_stats_update(dev, vq, pkts, count);
> +       vhost_queue_stats_update(dev, vq, pkts, nb_rx);
> 
> out:
>        vhost_user_iotlb_rd_unlock(vq);
> @@ -4322,8 +4316,8 @@ rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
>        rte_rwlock_read_unlock(&vq->access_lock);
> 
>        if (unlikely(rarp_mbuf != NULL))
> -               count += 1;
> +               nb_rx += 1;
> 
> out_no_unlock:
> -       return count;
> +       return nb_rx;
> }
> --
> 2.47.1
> 

Reviewed-by: Chenbo Xia <chenbox@nvidia.com>


  parent reply	other threads:[~2025-01-16 12:15 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-16  9:54 [PATCH v3 0/3] vhost: fix and improve dequeue error path Maxime Coquelin
2025-01-16  9:54 ` [PATCH v3 1/3] vhost: fix missing packets count reset when not ready Maxime Coquelin
2025-01-16 10:10   ` David Marchand
2025-01-16 12:14   ` Chenbo Xia
2025-01-16  9:54 ` [PATCH v3 2/3] vhost: rework dequeue paths error handling Maxime Coquelin
2025-01-16 10:10   ` David Marchand
2025-01-16 12:15   ` Chenbo Xia [this message]
2025-01-16  9:54 ` [PATCH v3 3/3] vhost: improve RARP handling in dequeue paths Maxime Coquelin
2025-01-16 10:12   ` David Marchand
2025-01-16 12:15   ` Chenbo Xia
2025-01-16 13:08   ` David Marchand

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