[dpdk-dev] [PATCH v3 3/4] vhost: fix unnecessary vring_state_changed call

[Maxime Coquelin]

On 4/20/21 10:57 AM, Jiayu Hu wrote:
> When VHOST_USER_F_PROTOCOL_FEATURES is not negotiated,
> there is no need for vhost_user_set_vring_kick() to
> notify the application of vring enabled, as
> vhost_user_msg_handler() also notifies the application.
> 
> This patch is to remove unnecessary vring_state_changed() call.
> 
> Fixes: 966027b4b3a3 ("vhost: fix silent queue enabling with legacy guests")

Sorry, I thought the vring_state_changed cb was introduced when Matan
did the rework last year, but it is actually older.

If we backport the patch on v19.11, we will create a regression as it
will revert Ilya's patch.

I think that your fix is correct only once Matan's series is present, so
we should have below Fixes tag:

Fixes: d0fcc38f5fa4 ("vhost: improve device readiness notifications")

> Cc: stable at dpdk.org
> 
> Signed-off-by: Jiayu Hu <jiayu.hu at intel.com>
> Tested-by: Yinan Wang <yinan.wang at intel.com>
> ---
>  lib/librte_vhost/vhost_user.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index fa8929f..611ff20 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1922,9 +1922,6 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg,
>  	 */
>  	if (!(dev->features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) {
>  		vq->enabled = true;
> -		if (dev->notify_ops->vring_state_changed)
> -			dev->notify_ops->vring_state_changed(
> -				dev->vid, file.index, 1);
>  	}
>  
>  	if (vq->ready) {
> 

With the fixes tag changed:
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>

Chanbo, can you change the Fixes tag while applying or Jiayu needs to
send a new revision?

Thanks,
Maxime