> On Fri, Aug 09, 2019 at 12:18:47PM +0530, Pankaj Gupta wrote:
> > This patch decrements 'next_avail_idx' count when detaching a buffer
> > from vq for packed ring code. Split ring code already does this in
> > virtqueue_detach_unused_buf_split function. This updates the
> > 'next_avail_idx' to the previous correct index after an unused buffer
> > is detatched from the vq.
> >
> > Signed-off-by: Pankaj Gupta <pagupta@xxxxxxxxxx>
>
> I would make this patch 1, not patch 2, otherwise
> patch 1 corrupts the ring.
Sure. Will post this patch as patch 1 in next version.
Thanks,
Pankaj
>
>
> > ---
> > drivers/virtio/virtio_ring.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index c8be1c4f5b55..7c69181113e2 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -1537,6 +1537,12 @@ static void
> > *virtqueue_detach_unused_buf_packed(struct virtqueue *_vq)
> > /* detach_buf clears data, so grab it now. */
> > buf = vq->packed.desc_state[i].data;
> > detach_buf_packed(vq, i, NULL);
> > + vq->packed.next_avail_idx--;
> > + if (vq->packed.next_avail_idx < 0) {
> > + vq->packed.next_avail_idx = vq->packed.vring.num - 1;
> > + vq->packed.avail_wrap_counter ^= 1;
> > + }
> > +
> > END_USE(vq);
> > return buf;
> > }
> > --
> > 2.20.1
>
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