Re: [Qemu-devel] [PATCH] vhost-user: fix watcher need be removed when vhost-user hotplug

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Jul 21, 2017 at 11:19:04AM +0000, Marc-André Lureau wrote:
> Hi
> 
> On Fri, Jul 21, 2017 at 7:18 AM w00273186 <wangyunjian@huawei.com> wrote:
> 
>     From: Yunjian Wang <wangyunjian@huawei.com>
> 
>     "nc" is freed after hotplug vhost-user, but the watcher don't be removed.
>     The QEMU crash when the watcher access the "nc" on socket disconnect.
> 
> 
> 
> This is actually your 3rd iteration on the patch
> 
> Could your describe your changes since:
> "[PATCH v2] vhost-user: fix watcher need be removed when vhost-user hotplug"
> 
> Thanks

Yes but it's a 3-liner. That's way below the limit where you need
detailed change history. Does the patch make sense to you?

> 
>         Program received signal SIGSEGV, Segmentation fault.
>         #0  object_get_class (obj=obj@entry=0x2) at qom/object.c:750
>         #1  0x00007f9bb4180da1 in qemu_chr_fe_disconnect (be=<optimized out>)
>     at chardev/char-fe.c:372
>         #2  0x00007f9bb40d1100 in net_vhost_user_watch (chan=<optimized out>,
>     cond=<optimized out>, opaque=<optimized out>) at net/vhost-user.c:188
>         #3  0x00007f9baf97f99a in g_main_context_dispatch () from /usr/lib64/
>     libglib-2.0.so.0
>         #4  0x00007f9bb41d7ebc in glib_pollfds_poll () at util/main-loop.c:213
>         #5  os_host_main_loop_wait (timeout=<optimized out>) at util/
>     main-loop.c:261
>         #6  main_loop_wait (nonblocking=nonblocking@entry=0) at util/
>     main-loop.c:515
>         #7  0x00007f9bb3e266a7 in main_loop () at vl.c:1917
>         #8  main (argc=<optimized out>, argv=<optimized out>, envp=<optimized
>     out>) at vl.c:4786
> 
>     Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
>     ---
>      net/vhost-user.c | 4 ++++
>      1 file changed, 4 insertions(+)
> 
>     diff --git a/net/vhost-user.c b/net/vhost-user.c
>     index 36f32a2..c23927c 100644
>     --- a/net/vhost-user.c
>     +++ b/net/vhost-user.c
>     @@ -151,6 +151,10 @@ static void vhost_user_cleanup(NetClientState *nc)
>              s->vhost_net = NULL;
>          }
>          if (nc->queue_index == 0) {
>     +        if (s->watch) {
>     +            g_source_remove(s->watch);
>     +            s->watch = 0;
>     +        }
>              qemu_chr_fe_deinit(&s->chr, true);
>          }
> 
>     --
>     1.8.3.1
> 
> 
> 
> 
> --
> Marc-André Lureau