Re: [PATCH] virtio: fix memory leak of virtqueue memzones

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

On Tue, Apr 26, 2016 at 12:32:12PM +0000, Jianfeng Tan wrote:
> Issue: When virtio was proposed in DPDK, there is no API to free memzones.
> But this has changed since rte_memzone_free() has been implemented by
> commit ff909fe21f.

The more proper way to reference a commit is

	commit_id ("$commit_subject")

Like what the fixline does.

> This patch is to make sure memzones in struct virtqueue, like mz and
> virtio_net_hdr_mz, are freed when queue is released or setup fails.
> 
> Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
> ---
>  drivers/net/virtio/virtio_ethdev.c | 69 ++++++++++++++++++++------------------
>  drivers/net/virtio/virtio_ethdev.h |  2 +-
>  drivers/net/virtio/virtio_rxtx.c   |  4 +--
>  3 files changed, 40 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index 63a368a..54eacf6 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -261,12 +261,18 @@ virtio_set_multiple_queues(struct rte_eth_dev *dev, uint16_t nb_queues)
>  }
>  
>  void
> -virtio_dev_queue_release(struct virtqueue *vq) {
> +virtio_dev_queue_release(struct virtqueue *vq, int io_related)
> +{
>  	struct virtio_hw *hw;
>  
>  	if (vq) {
>  		hw = vq->hw;
> -		hw->vtpci_ops->del_queue(hw, vq);
> +		if (io_related)
> +			hw->vtpci_ops->del_queue(hw, vq);

What is "io_related" supposed to mean here, queue has been started/set
up? If so, "started" might be better. And remember to put it into the vq
struct: we don't need an extra parameter for that.

> +
> +		rte_memzone_free(vq->mz);
> +		if (vq->virtio_net_hdr_mz)
> +			rte_memzone_free(vq->virtio_net_hdr_mz);
>  
>  		rte_free(vq->sw_ring);
>  		rte_free(vq);
> @@ -286,6 +292,7 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
>  	unsigned int vq_size, size;
>  	struct virtio_hw *hw = dev->data->dev_private;
>  	struct virtqueue *vq = NULL;
> +	const char *queue_names[] = {"rvq", "txq", "cvq"};
>  
>  	PMD_INIT_LOG(DEBUG, "setting up queue: %u", vtpci_queue_idx);
>  
> @@ -305,34 +312,34 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
>  		return -EINVAL;
>  	}
>  
> -	if (queue_type == VTNET_RQ) {
> -		snprintf(vq_name, sizeof(vq_name), "port%d_rvq%d",
> -			dev->data->port_id, queue_idx);
> -		vq = rte_zmalloc(vq_name, sizeof(struct virtqueue) +
> -			vq_size * sizeof(struct vq_desc_extra), RTE_CACHE_LINE_SIZE);
> -		vq->sw_ring = rte_zmalloc_socket("rxq->sw_ring",
> -			(RTE_PMD_VIRTIO_RX_MAX_BURST + vq_size) *
> -			sizeof(vq->sw_ring[0]), RTE_CACHE_LINE_SIZE, socket_id);
> -	} else if (queue_type == VTNET_TQ) {
> -		snprintf(vq_name, sizeof(vq_name), "port%d_tvq%d",
> -			dev->data->port_id, queue_idx);
> -		vq = rte_zmalloc(vq_name, sizeof(struct virtqueue) +
> -			vq_size * sizeof(struct vq_desc_extra), RTE_CACHE_LINE_SIZE);
> -	} else if (queue_type == VTNET_CQ) {
> -		snprintf(vq_name, sizeof(vq_name), "port%d_cvq",
> -			dev->data->port_id);
> -		vq = rte_zmalloc(vq_name, sizeof(struct virtqueue) +
> -			vq_size * sizeof(struct vq_desc_extra),
> -			RTE_CACHE_LINE_SIZE);
> +	if (queue_type < VTNET_RQ || queue_type > VTNET_RQ) {
> +		PMD_INIT_LOG(ERR, "invalid queue type: %d", queue_type);
> +		return -EINVAL;
>  	}
> +
> +	snprintf(vq_name, sizeof(vq_name), "port%d_%s%d",
> +		 dev->data->port_id, queue_names[queue_type], queue_idx);
> +	vq = rte_zmalloc(vq_name, sizeof(struct virtqueue) +
> +			 vq_size * sizeof(struct vq_desc_extra),
> +			 RTE_CACHE_LINE_SIZE);

This is a cleanup, a good cleanup. So, make a patch for that, and do
NOT mix cleanup and fix in one single patch, which is something I
have told you quite few times, right?


	--yliu