Commit 258dc7c9 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin
Browse files

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: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 492fb99c

hw/virtio.c

+11 −0
Original line number Diff line number Diff line
@@ -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)