Re: [PATCH V2 4/9] vhost: reset invalidate_count in vhost_set_vring_num_addr()

[Jason Wang]

On 2019/8/1 äå3:32, Jason Gunthorpe wrote:
> On Wed, Jul 31, 2019 at 09:29:28PM +0800, Jason Wang wrote:
> > On 2019/7/31 äå8:41, Jason Gunthorpe wrote:
> > > On Wed, Jul 31, 2019 at 04:46:50AM -0400, Jason Wang wrote:
> > > > The vhost_set_vring_num_addr() could be called in the middle of
> > > > invalidate_range_start() and invalidate_range_end(). If we don't reset
> > > > invalidate_count after the un-registering of MMU notifier, the
> > > > invalidate_cont will run out of sync (e.g never reach zero). This will
> > > > in fact disable the fast accessor path. Fixing by reset the count to
> > > > zero.
> > > >
> > > > Reported-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> > > Did Michael report this as well?
> >
> > Correct me if I was wrong. I think it's point 4 described in
> > https://lkml.org/lkml/2019/7/21/25.
> I'm not sure what that is talking about
>
> But this fixes what I described:
>
> https://lkml.org/lkml/2019/7/22/554
>
> Jason


I'm sorry I miss this, will add your name as reported-by in the next 
version.

Thanks