Re: 9p regression (Was: [PATCH v2] virtio_ring: don't update event idx on get_buf)

[Luis Chamberlain]

On Tue, Mar 28, 2023 at 11:13:32AM +0900, Dominique Martinet wrote:
> Hi Michael, Albert,
> 
> Albert Huang wrote on Sat, Mar 25, 2023 at 06:56:33PM +0800:
> > in virtio_net, if we disable the napi_tx, when we triger a tx interrupt,
> > the vq->event_triggered will be set to true. It will no longer be set to
> > false. Unless we explicitly call virtqueue_enable_cb_delayed or
> > virtqueue_enable_cb_prepare.
> 
> This patch (commited as 35395770f803 ("virtio_ring: don't update event
> idx on get_buf") in next-20230327 apparently breaks 9p, as reported by
> Luis in https://lkml.kernel.org/r/ZCI+7Wg5OclSlE8c@xxxxxxxxxxxxxxxxxxxxxx

Spot on, reverting that commit fixes it.

  Luis