[PATCH v3] vhost: fix deadlock when message handling failed

[Xia, Chenbo]

> -----Original Message-----
> From: Pei, Andy <andy.pei at intel.com>
> Sent: Monday, July 11, 2022 4:42 PM
> To: Maxime Coquelin <maxime.coquelin at redhat.com>; Ma, WenwuX
> <wenwux.ma at intel.com>; Xia, Chenbo <chenbo.xia at intel.com>; dev at dpdk.org
> Cc: Hu, Jiayu <jiayu.hu at intel.com>; Wang, Yinan <yinan.wang at intel.com>; He,
> Xingguang <xingguang.he at intel.com>; stable at dpdk.org
> Subject: RE: [PATCH v3] vhost: fix deadlock when message handling failed
> 
> HI ALL,
> 
> I see that in function vhost_user_msg_handler.
> We use "ret" to store both vhost msg return code like
> "RTE_VHOST_MSG_RESULT_XXX" and function return value.
> I wonder if it is better to use two different variable to make it easy to
> read.

By saying 'function return value', you mean which function? Can you
elaborate more?

Thanks,
Chenbo

> 
> > -----Original Message-----
> > From: Maxime Coquelin <maxime.coquelin at redhat.com>
> > Sent: Tuesday, May 17, 2022 9:24 PM
> > To: Ma, WenwuX <WenwuX.Ma at intel.com>; Xia, Chenbo
> > <Chenbo.Xia at intel.com>; dev at dpdk.org
> > Cc: Hu, Jiayu <Jiayu.Hu at intel.com>; Wang, Yinan <yinan.wang at intel.com>;
> He,
> > Xingguang <xingguang.he at intel.com>; stable at dpdk.org
> > Subject: Re: [PATCH v3] vhost: fix deadlock when message handling failed
> >
> >
> >
> > On 5/7/22 15:27, Wenwu Ma wrote:
> > > In vhost_user_msg_handler(), if vhost message handling failed, we
> > > should check whether the queue is locked and release the lock before
> > > returning. Or, it will cause a deadlock later.
> > >
> > > Fixes: 7f31d4ea05ca ("vhost: fix lock on device readiness
> > > notification")
> > > Cc: stable at dpdk.org
> > >
> > > Signed-off-by: Wenwu Ma <wenwux.ma at intel.com>
> > > ---
> > >   lib/vhost/vhost_user.c | 10 ++++++----
> > >   1 file changed, 6 insertions(+), 4 deletions(-)
> > >
> >
> > Applied to dpdk-next-virtio/main.
> >
> > Thanks,
> > Maxime