Re: [dpdk-dev] [PATCH 2/2] net/virtio: fix Tx completed mbufs leak on device stop

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 8/18/21 4:13 PM, Andrew Rybchenko wrote:
> From: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
> 
> Free Tx completed mbufs on device stop. Not completed Tx mbufs cannot be
> freed since they are still in use.
> 
> Fixes: c1f86306a02 ("virtio: add new driver")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
> Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> ---
>  drivers/net/virtio/virtio_ethdev.c | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index e58085a2c9..ed3fefee7c 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -2393,6 +2393,34 @@ static void virtio_dev_free_mbufs(struct rte_eth_dev *dev)
>  	PMD_INIT_LOG(DEBUG, "%d mbufs freed", mbuf_num);
>  }
>  
> +static void
> +virtio_tx_completed_cleanup(struct rte_eth_dev *dev)
> +{
> +	struct virtio_hw *hw = dev->data->dev_private;
> +	struct virtqueue *vq;
> +	int qidx;
> +	void (*xmit_cleanup)(struct virtqueue *vq, uint16_t nb_used);
> +
> +	if (virtio_with_packed_queue(hw)) {
> +		if (hw->use_vec_tx)
> +			xmit_cleanup = &virtio_xmit_cleanup_inorder_packed;
> +		else if (virtio_with_feature(hw, VIRTIO_F_IN_ORDER))
> +			xmit_cleanup = &virtio_xmit_cleanup_inorder_packed;
> +		else
> +			xmit_cleanup = &virtio_xmit_cleanup_normal_packed;
> +	} else {
> +		if (hw->use_inorder_tx)
> +			xmit_cleanup = &virtio_xmit_cleanup_inorder;
> +		else
> +			xmit_cleanup = &virtio_xmit_cleanup;
> +	}
> +
> +	for (qidx = 0; qidx < hw->max_queue_pairs; qidx++) {
> +		vq = hw->vqs[2 * qidx + VTNET_SQ_TQ_QUEUE_IDX];

Maybe add a check to ensure that vq is non-NULL since it is dereferenced
later without checking.

> +		xmit_cleanup(vq, virtqueue_nused(vq));
> +	}
> +}
> +
>  /*
>   * Stop device: disable interrupt and mark link down
>   */
> @@ -2411,6 +2439,8 @@ virtio_dev_stop(struct rte_eth_dev *dev)
>  		goto out_unlock;
>  	hw->started = 0;
>  
> +	virtio_tx_completed_cleanup(dev);
> +
>  	if (intr_conf->lsc || intr_conf->rxq) {
>  		virtio_intr_disable(dev);
>  
>