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Date:   Mon, 27 Mar 2023 21:49:40 -0700
From:   Luis Chamberlain <mcgrof@kernel.org>
To:     Dominique Martinet <asmadeus@codewreck.org>
Cc:     Albert Huang <huangjie.albert@bytedance.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
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        Eric Van Hensbergen <ericvh@gmail.com>,
        Christian Schoenebeck <linux_oss@crudebyte.com>
Subject: Re: 9p regression (Was: [PATCH v2] virtio_ring: don't update event
 idx on get_buf)
Message-ID: <ZCJx5Dtms5iDhftF@bombadil.infradead.org>
References: <20230325105633.58592-1-huangjie.albert@bytedance.com>
 <ZCJNTBQLZeyLBKKB@codewreck.org>
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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@bombadil.infradead.org

Spot on, reverting that commit fixes it.

  Luis