Re: [PATCH v3 1/2] vhost-user: Refactor vhost acked features saving

[Michael S. Tsirkin]

On Sun, Oct 30, 2022 at 09:52:38PM +0800, huangy81@chinatelecom.cn wrote:
> From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
> 
> Abstract vhost acked features saving into
> vhost_user_save_acked_features, export it as util function.
> 
> Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
> Signed-off-by: Guoyi Tu <tugy@chinatelecom.cn>
> ---
>  include/net/vhost-user.h |  2 ++
>  net/vhost-user.c         | 29 ++++++++++++++++++-----------
>  2 files changed, 20 insertions(+), 11 deletions(-)
> 
> diff --git a/include/net/vhost-user.h b/include/net/vhost-user.h
> index 5bcd8a6..00d4661 100644
> --- a/include/net/vhost-user.h
> +++ b/include/net/vhost-user.h
> @@ -14,5 +14,7 @@
>  struct vhost_net;
>  struct vhost_net *vhost_user_get_vhost_net(NetClientState *nc);
>  uint64_t vhost_user_get_acked_features(NetClientState *nc);
> +void vhost_user_save_acked_features(NetClientState *nc,
> +                                    bool cleanup);
>  
>  #endif /* VHOST_USER_H */
> diff --git a/net/vhost-user.c b/net/vhost-user.c
> index b1a0247..74f349c 100644
> --- a/net/vhost-user.c
> +++ b/net/vhost-user.c
> @@ -45,24 +45,31 @@ uint64_t vhost_user_get_acked_features(NetClientState *nc)
>      return s->acked_features;
>  }
>  
> -static void vhost_user_stop(int queues, NetClientState *ncs[])
> +void vhost_user_save_acked_features(NetClientState *nc, bool cleanup)
>  {
>      NetVhostUserState *s;
> +
> +    s = DO_UPCAST(NetVhostUserState, nc, nc);
> +    if (s->vhost_net) {
> +        uint64_t features = vhost_net_get_acked_features(s->vhost_net);
> +        if (features) {
> +            s->acked_features = features;
> +        }
> +
> +        if (cleanup) {
> +            vhost_net_cleanup(s->vhost_net);
> +        }
> +    }
> +}

I can't figure out what is going on here.  Why is there a cleanup flag?
What does cleanup have to do with saving acked features?
I suspect it's better to just leave this part in the caller.

> +
> +static void vhost_user_stop(int queues, NetClientState *ncs[])
> +{
>      int i;
>  
>      for (i = 0; i < queues; i++) {
>          assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
>  
> -        s = DO_UPCAST(NetVhostUserState, nc, ncs[i]);
> -
> -        if (s->vhost_net) {
> -            /* save acked features */
> -            uint64_t features = vhost_net_get_acked_features(s->vhost_net);
> -            if (features) {
> -                s->acked_features = features;
> -            }
> -            vhost_net_cleanup(s->vhost_net);
> -        }
> +        vhost_user_save_acked_features(ncs[i], true);
>      }
>  }
>  
> -- 
> 1.8.3.1