On 2019/8/1 上午3:32, Jason Gunthorpe wrote:

On Wed, Jul 31, 2019 at 09:29:28PM +0800, Jason Wang wrote:

quoted

On 2019/7/31 下午8:41, Jason Gunthorpe wrote:

quoted

On Wed, Jul 31, 2019 at 04:46:50AM -0400, Jason Wang wrote:

quoted

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@redhat.com>

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