Commit f6049f44 authored by Peter Maydell's avatar Peter Maydell
Browse files

hw/virtio/virtio: Don't allow guests to add/remove queues 



A queue size of 0 is used to indicate a nonexistent queue, so
don't allow the guest to flip a queue between zero-size and
non-zero-size. Don't permit setting of negative queue sizes
either.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Message-id: 1374853288-9912-2-git-send-email-peter.maydell@linaro.org
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 2e985fe0

hw/virtio/virtio.c

+9 −3
Original line number Diff line number Diff line
@@ -673,11 +673,17 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) 


void virtio_queue_set_num(VirtIODevice *vdev, int n, int num)

{

    if (num <= VIRTQUEUE_MAX_SIZE) {

    /* Don't allow guest to flip queue between existent and

     * nonexistent states, or to set it to an invalid size.

     */

    if (!!num != !!vdev->vq[n].vring.num ||

        num > VIRTQUEUE_MAX_SIZE ||

        num < 0) {

        return;

    }

    vdev->vq[n].vring.num = num;

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

}

}



int virtio_queue_get_num(VirtIODevice *vdev, int n)

{