Re: [dpdk-dev] [PATCH] vhost: add vDPA resource cleanup callback

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

Hi Xueming,

On 10/19/21 13:39, Xueming Li wrote:
> This patch adds vDPA device cleanup callback to release resources on
> vhost user connection close.
> 
> Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> ---
>   lib/vhost/rte_vdpa_dev.h | 3 +++
>   lib/vhost/vhost_user.c   | 6 ++++++
>   2 files changed, 9 insertions(+)
> 
> diff --git a/lib/vhost/rte_vdpa_dev.h b/lib/vhost/rte_vdpa_dev.h
> index b0f494815fa..2711004fe05 100644
> --- a/lib/vhost/rte_vdpa_dev.h
> +++ b/lib/vhost/rte_vdpa_dev.h
> @@ -32,6 +32,9 @@ struct rte_vdpa_dev_ops {
>   	/** Driver close the device (Mandatory) */
>   	int (*dev_close)(int vid);
>   
> +	/** Connection closed, clean up resources */
> +	int (*dev_cleanup)(int vid);
> +
>   	/** Enable/disable this vring (Mandatory) */
>   	int (*set_vring_state)(int vid, int vring, int state);
>   
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index 5a894ca0cc7..032b621c86c 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -162,6 +162,12 @@ free_mem_region(struct virtio_net *dev)
>   void
>   vhost_backend_cleanup(struct virtio_net *dev)
>   {
> +	struct rte_vdpa_device *vdpa_dev;
> +
> +	vdpa_dev = dev->vdpa_dev;
> +	if (vdpa_dev && vdpa_dev->ops->dev_cleanup != NULL)
> +		vdpa_dev->ops->dev_cleanup(dev->vid);
> +
>   	if (dev->mem) {
>   		free_mem_region(dev);
>   		rte_free(dev->mem);
> 

What will be done there that cannot be done in .dev_close()?
Having the mlx5 implementation of this callback alongside this patch may
help to understand.

Thanks,
Maxime