[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH] virtio: reset device on bad guest index in virtio_load()
From: |
Michael S. Tsirkin |
Subject: |
Re: [PATCH] virtio: reset device on bad guest index in virtio_load() |
Date: |
Wed, 2 Dec 2020 04:50:15 -0500 |
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.levon@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
>
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- Re: [PATCH] virtio: reset device on bad guest index in virtio_load(),
Michael S. Tsirkin <=