diff options
| -rw-r--r-- | hw/virtio/virtio-mmio.c | 3 | ||||
| -rw-r--r-- | hw/virtio/virtio.c | 12 |
2 files changed, 12 insertions, 3 deletions
diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c index 88cf994b97..4bd29533f3 100644 --- a/hw/virtio/virtio-mmio.c +++ b/hw/virtio/virtio-mmio.c @@ -151,6 +151,9 @@ static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size) } return proxy->host_features; case VIRTIO_MMIO_QUEUENUMMAX: + if (!virtio_queue_get_num(vdev, vdev->queue_sel)) { + return 0; + } return VIRTQUEUE_MAX_SIZE; case VIRTIO_MMIO_QUEUEPFN: return virtio_queue_get_addr(vdev, vdev->queue_sel) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 09f62c6c70..60653f764e 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -673,10 +673,16 @@ 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) { - vdev->vq[n].vring.num = num; - virtqueue_init(&vdev->vq[n]); + /* 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) |