On Mon, Dec 16, 2019 at 10:30:50AM +0800, Li hangjing wrote:
> From: Li Hangjing <lihangjing@baidu.com>
> 
> When the number of a virtio-blk device's virtqueues is larger than
> BITS_PER_LONG, the out-of-bounds access to bitmap[ ] will occur.
> 
> Fixes: e21737ab15 ("virtio-blk: multiqueue batch notify")
> Cc: qemu-stable@nongnu.org
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Li Hangjing <lihangjing@baidu.com>
> Reviewed-by: Xie Yongji <xieyongji@baidu.com>
> Reviewed-by: Chai Wen <chaiwen@baidu.com>
> ---
>  hw/block/dataplane/virtio-blk.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Ouch, thank you for the fix!  Applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan