ping
On Thu, May 15, 2025 at 9:32 AM Yuri Benditovich
<yuri.benditov...@daynix.com> wrote:
>
> virtio processes indirect descriptors even if the respected
> feature VIRTIO_RING_F_INDIRECT_DESC was not negotiated.
> If qemu is used with reduced set of features to emulate the
> hardware device that does not support indirect descriptors,
> the will probably trigger problematic flows on the hardware
> setup but do not reveal the mistake on qemu.
> Add LOG_GUEST_ERROR for such case. This will issue logs with
> '-d guest_errors' in the command line
>
> Signed-off-by: Yuri Benditovich <yuri.benditov...@daynix.com>
> ---
> hw/virtio/virtio.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 480c2e5036..8d185f282a 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -205,6 +205,15 @@ static const char *virtio_id_to_name(uint16_t device_id)
> return name;
> }
>
> +static void virtio_check_indirect_feature(VirtIODevice *vdev)
> +{
> + if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) {
> + qemu_log_mask(LOG_GUEST_ERROR,
> + "Device %s: indirect_desc was not negotiated!\n",
> + vdev->name);
> + }
> +}
> +
> /* Called within call_rcu(). */
> static void virtio_free_region_cache(VRingMemoryRegionCaches *caches)
> {
> @@ -1733,6 +1742,7 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t
> sz)
> virtio_error(vdev, "Invalid size for indirect buffer table");
> goto done;
> }
> + virtio_check_indirect_feature(vdev);
>
> /* loop over the indirect descriptor table */
> len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as,
> @@ -1870,6 +1880,7 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t
> sz)
> virtio_error(vdev, "Invalid size for indirect buffer table");
> goto done;
> }
> + virtio_check_indirect_feature(vdev);
>
> /* loop over the indirect descriptor table */
> len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as,
> --
> 2.40.1
>
