Virtualization - Apr 2021 - [PATCH v6 03/10] vhost-vdpa: protect concurrent access to vhost device iotlb

On Sun, Apr 11, 2021 at 01:36:18PM +0800, Yongji Xie
wrote:
> On Sat, Apr 10, 2021 at 12:16 AM Michael S. Tsirkin <mst at
redhat.com> wrote:
> >
> > On Wed, Mar 31, 2021 at 04:05:12PM +0800, Xie Yongji wrote:
> > > Use vhost_dev->mutex to protect vhost device iotlb from
> > > concurrent access.
> > >
> > > Fixes: 4c8cf318("vhost: introduce vDPA-based backend")
> > > Cc: stable at vger.kernel.org
> > > Signed-off-by: Xie Yongji <xieyongji at bytedance.com>
> > > Acked-by: Jason Wang <jasowang at redhat.com>
> > > Reviewed-by: Stefano Garzarella <sgarzare at redhat.com>
> >
> > I could not figure out whether there's a bug there now.
> > If yes when is the concurrent access triggered?
> >
> 
> When userspace sends the VHOST_IOTLB_MSG_V2 message concurrently?
> 
> vhost_vdpa_chr_write_iter -> vhost_chr_write_iter ->
> vhost_vdpa_process_iotlb_msg()
> 
> Thanks,
> Yongji
And then what happens currently?

-- 
MST