On Sat, Oct 29, 2022 at 12:48 AM Philippe Mathieu-Daudé
<phi...@linaro.org> wrote:
>
> On 28/10/22 18:02, Eugenio Pérez wrote:
> > This causes errors on virtio modern devices on big endian hosts
> >
> > Fixes: 01f8beacea2a ("vhost: toggle device callbacks using used event idx")
> > Signed-off-by: Eugenio Pérez <epere...@redhat.com>
> > ---
> > hw/virtio/vhost-shadow-virtqueue.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/virtio/vhost-shadow-virtqueue.c
> > b/hw/virtio/vhost-shadow-virtqueue.c
> > index 70766ea740..467099f5d9 100644
> > --- a/hw/virtio/vhost-shadow-virtqueue.c
> > +++ b/hw/virtio/vhost-shadow-virtqueue.c
> > @@ -382,7 +382,7 @@ static bool
> > vhost_svq_enable_notification(VhostShadowVirtqueue *svq)
> > {
> > if (virtio_vdev_has_feature(svq->vdev, VIRTIO_RING_F_EVENT_IDX)) {
> > uint16_t *used_event = &svq->vring.avail->ring[svq->vring.num];
> > - *used_event = svq->shadow_used_idx;
> > + *used_event = cpu_to_le16(svq->shadow_used_idx);
>
> This looks correct, but what about:
>
> virtio_stw_p(svq->vdev, used_event, svq->shadow_used_idx);
>
Hi Philippe,
I think this has the same answer as [1], the endianness conversion
from the guest to the host may not be the same as the one needed from
qemu SVQ to the vdpa device. Please let me know if it is not the case.
Thanks!
[1] https://lists.nongnu.org/archive/html/qemu-devel/2022-10/msg06081.html
> > } else {
> > svq->vring.avail->flags &=
> > ~cpu_to_le16(VRING_AVAIL_F_NO_INTERRUPT);
> > }
>
