[v3,2/3] vhost: rework dequeue paths error handling

Message ID 20250116095416.3655699-3-maxime.coquelin@redhat.com (mailing list archive)
State Accepted
Delegated to: Maxime Coquelin
Headers
Series vhost: fix and improve dequeue error path |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Maxime Coquelin Jan. 16, 2025, 9:54 a.m. UTC
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(-)
  

Comments

David Marchand Jan. 16, 2025, 10:10 a.m. UTC | #1
On Thu, Jan 16, 2025 at 10:54 AM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> 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>

Reviewed-by: David Marchand <david.marchand@redhat.com>
  
Chenbo Xia Jan. 16, 2025, 12:15 p.m. UTC | #2
> 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>
  

Patch

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;
 }