On Tue, Nov 26, 2019 at 05:06:28PM -0300, Julio Faracco wrote:
> Driver virtio_net is not handling error events for TX provided by
> dev_watchdog. This event is reached when transmission queue is having
> problems to transmit packets. This could happen for any reason. To
> enable it, driver should have .ndo_tx_timeout implemented.
>
> This commit brings back virtnet_reset method to recover TX queues from a
> error state. That function is called by schedule_work method and it puts
> the reset function into work queue.
>
> As the error cause is unknown at this moment, it would be better to
> reset all queues, including RX (because we don't have control of this).
>
> Signed-off-by: Julio Faracco
> Signed-off-by: Daiane Mendes
> Cc: Jason Wang
> ---
> drivers/net/virtio_net.c | 83 +++-
> 1 file changed, 82 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 4d7d5434cc5d..fbe1dfde3a4b 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -75,6 +75,7 @@ struct virtnet_sq_stats {
> u64 xdp_tx;
> u64 xdp_tx_drops;
> u64 kicks;
> + u64 tx_timeouts;
> };
>
> struct virtnet_rq_stats {
> @@ -98,6 +99,7 @@ static const struct virtnet_stat_desc
> virtnet_sq_stats_desc[] = {
> { "xdp_tx", VIRTNET_SQ_STAT(xdp_tx) },
> { "xdp_tx_drops", VIRTNET_SQ_STAT(xdp_tx_drops) },
> { "kicks", VIRTNET_SQ_STAT(kicks) },
> + { "tx_timeouts",VIRTNET_SQ_STAT(tx_timeouts) },
> };
>
> static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
> @@ -211,6 +213,9 @@ struct virtnet_info {
> /* Work struct for config space updates */
> struct work_struct config_work;
>
> + /* Work struct for resetting the virtio-net driver. */
> + struct work_struct reset_work;
> +
> /* Does the affinity hint is set for virtqueues? */
> bool affinity_hint_set;
>
> @@ -1721,7 +1726,7 @@ static void virtnet_stats(struct net_device *dev,
> int i;
>
> for (i = 0; i < vi->max_queue_pairs; i++) {
> - u64 tpackets, tbytes, rpackets, rbytes, rdrops;
> + u64 tpackets, tbytes, terrors, rpackets, rbytes, rdrops;
> struct receive_queue *rq = >rq[i];
> struct send_queue *sq = >sq[i];
>
> @@ -1729,6 +1734,7 @@ static void virtnet_stats(struct net_device *dev,
> start = u64_stats_fetch_begin_irq(>stats.syncp);
> tpackets = sq->stats.packets;
> tbytes = sq->stats.bytes;
> + terrors = sq->stats.tx_timeouts;
> } while (u64_stats_fetch_retry_irq(>stats.syncp, start));
>
> do {
> @@ -1743,6 +1749,7 @@ static void virtnet_stats(struct net_device *dev,
> tot->rx_bytes += rbytes;
> tot->tx_bytes += tbytes;
> tot->rx_dropped += rdrops;
> + tot->tx_errors += terrors;
> }
>
> tot->tx_dropped = dev->stats.tx_dropped;
> @@ -2578,6 +2585,21 @@ static int virtnet_set_features(struct net_device *dev,
> return 0;
> }
>
> +static void virtnet_tx_timeout(struct net_device *dev, unsigned int txqueue)
> +{
> + struct virtnet_info *vi = netdev_priv(dev);
> + struct send_queue *sq = >sq[txqueue];
> +
> + netdev_warn(dev, "TX timeout on queue: %d, sq: %s, vq: %d, name: %s\n",
> + txqueue, sq->name, sq->vq->index, sq->vq->name);
> +
> + u64_stats_update_begin(>stats.syncp);
> + sq->stats.tx_timeouts++;
> + u64_stats_update_end(>stats.syncp);
> +
> + schedule_work(>reset_work);
> +}
> +
> static const struct net_device_ops virtnet_netdev = {
> .ndo_open= virtnet_open,
> .ndo_stop= virtnet_close,
> @@ -2593,6 +2615,7 @@ static const struct net_device_ops virtnet_netdev = {
> .ndo_features_check = passthru_features_check,
> .ndo_get_phys_port_name = virtnet_get_phys_port_name,
> .ndo_set_features = virtnet_set_features,
> + .ndo_tx_timeout = virtnet_tx_timeout,
> };
>
> static void virtnet_config_changed_work(struct work_struct *work)
> @@ -2982,6 +3005,62 @@ static int virtnet_validate(struct virtio_device *vdev)
> return 0;
> }
>
> +static void _remove_vq_common(struct virtnet_info *vi)
> +{
> + vi->vdev->config->reset(vi->vdev);
> +
> + /* Free unused buffers in both send and recv, if any. */
> + free_unused_bufs(vi);
> +
> + _free_receive_bufs(vi);
> +
> + free_receive_page_frags(vi);
> +
> + virtnet_del_vqs(vi);
> +}
> +
> +static int _virtnet_reset(struct virtnet_info *vi)
> +{
> + struct virtio_device *vdev = vi->vdev;
> + int ret;
> +
> + virtio_config_disable(vdev);
> + vdev->failed = vdev->config->get_status(vdev) & VIRTIO_CONFIG_S_FAILED;
> +
> + virtnet_freeze_down(vdev);
> +
