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Date: Wed, 21 Oct 2015 13:39:53 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
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References: <1445418438-24244-1-git-send-email-yuanhan.liu@linux.intel.com>
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In-Reply-To: <1445418438-24244-4-git-send-email-yuanhan.liu@linux.intel.com>
Subject: Re: [Qemu-devel] [PATCH v2 4/5] Revert "vhost-user: Send
 VHOST_RESET_OWNER on vhost stop"
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To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Luke Gorrie <luke@snabb.co>, qemu-devel@nongnu.org

On Wed, Oct 21, 2015 at 05:07:17PM +0800, Yuanhan Liu wrote:
> Don't send VHOST_RESET_OWNER, for as Michael stated:
> 
>     Because we need to get the state from remote after stop.
>     RESET_OWNER discards that, so we can't resume the VM.
> 
> This reverts commit 294ce717e0f212ed0763307f3eab72b4a1bdf4d0.
> 
> Cc: Luke Gorrie <luke@snabb.co>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

Yes but poking at guest memory after driver is unloaded
is even worse.

> ---
>  hw/net/vhost_net.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index 804f5c9..95da5f8 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -293,13 +293,6 @@ static void vhost_net_stop_one(struct vhost_net *net,
>                                            &file);
>              assert(r >= 0);
>          }
> -    } else if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
> -        for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
> -            const VhostOps *vhost_ops = net->dev.vhost_ops;
> -            int r = vhost_ops->vhost_call(&net->dev, VHOST_RESET_OWNER,
> -                                          NULL);
> -            assert(r >= 0);
> -        }
>      }
>      if (net->nc->info->poll) {
>          net->nc->info->poll(net->nc, true);
> -- 
> 1.9.0
>