Re: [PATCH v7 11/12] vduse: Introduce VDUSE - vDPA Device in Userspace

[Jason Wang]

在 2021/5/27 下午12:57, Yongji Xie 写道:
> On Thu, May 27, 2021 at 12:13 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
> > 在 2021/5/17 下午5:55, Xie Yongji 写道:
> > > +
> > > +static int vduse_dev_msg_sync(struct vduse_dev *dev,
> > > +                           struct vduse_dev_msg *msg)
> > > +{
> > > +     init_waitqueue_head(&msg->waitq);
> > > +     spin_lock(&dev->msg_lock);
> > > +     vduse_enqueue_msg(&dev->send_list, msg);
> > > +     wake_up(&dev->waitq);
> > > +     spin_unlock(&dev->msg_lock);
> > > +     wait_event_killable(msg->waitq, msg->completed);
> >
> > What happens if the userspace(malicous) doesn't give a response forever?
> >
> > It looks like a DOS. If yes, we need to consider a way to fix that.
> How about using wait_event_killable_timeout() instead?


Probably, and then we need choose a suitable timeout and more important, 
need to report the failure to virtio.

Thanks


> Thanks,
> Yongji