virtio: sanity-check available index

Checking available index upon load instead of
only when vm is running makes is easier to
debug failures.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2010-10-17 20:23:48 +02:00
parent 492fb99c4b
commit 258dc7c96b

View File

@ -681,6 +681,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f)
uint32_t features;
uint32_t supported_features =
vdev->binding->get_features(vdev->binding_opaque);
uint16_t num_heads;
if (vdev->binding->load_config) {
ret = vdev->binding->load_config(vdev->binding_opaque, f);
@ -713,6 +714,16 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f)
if (vdev->vq[i].pa) {
virtqueue_init(&vdev->vq[i]);
}
num_heads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx;
/* Check it isn't doing very strange things with descriptor numbers. */
if (num_heads > vdev->vq[i].vring.num) {
fprintf(stderr, "VQ %d size 0x%x Guest index 0x%x "
"inconsistent with Host index 0x%x: delta 0x%x\n",
i, vdev->vq[i].vring.num,
vring_avail_idx(&vdev->vq[i]),
vdev->vq[i].last_avail_idx, num_heads);
return -1;
}
if (vdev->binding->load_queue) {
ret = vdev->binding->load_queue(vdev->binding_opaque, i, f);
if (ret)