Commit 1abeb5a6 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin
Browse files

virtio: fix up VQ checks 



When migration triggers before a VQ is initialized,
base pa is 0 and last_used_index must be 0 too:
we don't have a ring to compare to.

Reported-by: default avatarJuan Quintela <quintela@redhat.com>
Tested-by: default avatarJuan Quintela <quintela@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent ce67ed65

hw/virtio.c

+16 −11
Original line number Diff line number Diff line
@@ -682,7 +682,6 @@ 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);
@@ -713,16 +712,22 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f) 
        qemu_get_be16s(f, &vdev->vq[i].last_avail_idx);



        if (vdev->vq[i].pa) {

            uint16_t nheads;

            virtqueue_init(&vdev->vq[i]);

        }

	num_heads = vring_avail_idx(&vdev->vq[i]) - vdev->vq[i].last_avail_idx;

            nheads = 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) {

            if (nheads > vdev->vq[i].vring.num) {

                error_report("VQ %d size 0x%x Guest index 0x%x "

		             "inconsistent with Host index 0x%x: delta 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);

                             vdev->vq[i].last_avail_idx, nheads);

                return -1;

            }

        } else if (vdev->vq[i].last_avail_idx) {

            error_report("VQ %d address 0x0 "

                         "inconsistent with Host index 0x%x\n",

                         i, vdev->vq[i].last_avail_idx);

                return -1;

	}

        if (vdev->binding->load_queue) {