Re: [dpdk-dev] [PATCH 3/4] vhost: call vDPA callback at the end of vring enable handler

["Wang, Xiao W" <xiao.w.wang@intel.com>]

Hi Andy,

> -----Original Message-----
> From: Pei, Andy
> Sent: Friday, September 6, 2019 11:21 AM
> To: dev@dpdk.org
> Cc: Xu, Rosen <rosen.xu@intel.com>; Ye, Xiaolong <xiaolong.ye@intel.com>;
> Bie, Tiwei <tiwei.bie@intel.com>; Wang, Xiao W <xiao.w.wang@intel.com>
> Subject: [PATCH 3/4] vhost: call vDPA callback at the end of vring enable
> handler
> 
> vDPA's set_vring_state callback would need to know the virtqueues'
> enable status to configure the hardware.
> 
> Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
> Signed-off-by: Andy Pei <andy.pei@intel.com>
> ---
>  lib/librte_vhost/rte_vdpa.h   | 4 ++--
>  lib/librte_vhost/vhost_user.c | 5 +++--
>  2 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/librte_vhost/rte_vdpa.h b/lib/librte_vhost/rte_vdpa.h
> index 9a3deb3..19cf897 100644
> --- a/lib/librte_vhost/rte_vdpa.h
> +++ b/lib/librte_vhost/rte_vdpa.h
> @@ -54,8 +54,8 @@ struct rte_vdpa_dev_ops {
>  	int (*dev_conf)(int vid);
>  	int (*dev_close)(int vid);
> 
> -	/** Enable/disable this vring */
> -	int (*set_vring_state)(int vid, int vring, int state);
> +	/** Enable/disable vring queue pairs */
> +	int (*set_vring_state)(int vid);

If rte_vhost_get_active_vring_num() always needs be called inside set_vring_state callback,
inorder to get the active queue pair number, then why not pass the active queue pair number
directly as a parameter to set_vring_state() ? This could help to avoid exposing new API.

BRs,
Xiao

> 
>  	/** Set features when changed */
>  	int (*set_features)(int vid);
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 0b72648..21028cc 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1346,8 +1346,6 @@ static int vhost_user_set_vring_err(struct virtio_net
> **pdev __rte_unused,
> 
>  	did = dev->vdpa_dev_id;
>  	vdpa_dev = rte_vdpa_get_device(did);
> -	if (vdpa_dev && vdpa_dev->ops->set_vring_state)
> -		vdpa_dev->ops->set_vring_state(dev->vid, index, enable);
> 
>  	if (dev->notify_ops->vring_state_changed)
>  		dev->notify_ops->vring_state_changed(dev->vid,
> @@ -1359,6 +1357,9 @@ static int vhost_user_set_vring_err(struct virtio_net
> **pdev __rte_unused,
> 
>  	dev->virtqueue[index]->enabled = enable;
> 
> +	if (vdpa_dev && vdpa_dev->ops->set_vring_state)
> +		vdpa_dev->ops->set_vring_state(dev->vid);
> +
>  	return RTE_VHOST_MSG_RESULT_OK;
>  }
> 
> --
> 1.8.3.1