On Fri, Nov 20, 2020 at 06:51:07PM +0000, John Levon wrote: > > If we find a queue with an inconsistent guest index value, explicitly mark the > device as needing a reset - and broken - via virtio_error(). > > There's at least one driver implementation - the virtio-win NetKVM driver - > that > is able to handle a VIRTIO_CONFIG_S_NEEDS_RESET notification and successfully > restore the device to a working state. Other implementations do not correctly > handle this, but as the VQ is not in a functional state anyway, this is still > worth doing. > > Signed-off-by: John Levon <john.le...@nutanix.com>
I tagged this for after the release. pls ping me after the release to help make sure it does not get lost. > --- > hw/virtio/virtio.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index ceb58fda6c..eff35fab7c 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -3161,12 +3161,15 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int > version_id) > nheads = vring_avail_idx(&vdev->vq[i]) - > vdev->vq[i].last_avail_idx; > /* Check it isn't doing strange things with descriptor numbers. > */ > if (nheads > vdev->vq[i].vring.num) { > - qemu_log_mask(LOG_GUEST_ERROR, > - "VQ %d size 0x%x Guest index 0x%x " > - "inconsistent with Host index 0x%x: delta > 0x%x", > - i, vdev->vq[i].vring.num, > - vring_avail_idx(&vdev->vq[i]), > - vdev->vq[i].last_avail_idx, nheads); > + virtio_error(vdev, "VQ %d size 0x%x Guest index 0x%x " > + "inconsistent with Host index 0x%x: delta 0x%x", > + i, vdev->vq[i].vring.num, > + vring_avail_idx(&vdev->vq[i]), > + vdev->vq[i].last_avail_idx, nheads); > + vdev->vq[i].used_idx = 0; > + vdev->vq[i].shadow_avail_idx = 0; > + vdev->vq[i].inuse = 0; > + continue; > } > vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); > vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); > -- > 2.22.3 >