Re: [PATCH] virtio: add the queue number check

[Yang Zhong <yang.zhong@intel.com>]

On Fri, Jan 03, 2020 at 10:18:58PM +0100, Paolo Bonzini wrote:
> Il ven 3 gen 2020, 16:08 Yang Zhong <yang.zhong@intel.com> ha scritto:
> 
> >   I also tried virtio-blk device like below:
> >   https://patchwork.kernel.org/cover/10873193/
> >
> >   The virtio-blk can work with this changes, but vhost-user-blk device
> >   failed with this kernel patch.
> >
> >   in vhost_virtqueue_start() function, below operation to check if the
> >   desc addr set by guest kernel. This will ignore the extra vqs.
> >     a = virtio_queue_get_desc_addr(vdev, idx);
> >     if (a == 0) {
> >         /* Queue might not be ready for start */
> >         return 0;
> >     }
> >
> >   If guest kernel add min(cpu,num_vqs), do we need add same check in
> >   realize function of vhost-user-blk device?
> >
> 
> No. If virtio-blk works, the bug is in vhost-user-blk; if virtio-blk needs
> no check in cpu count, vhost-user-blk also doesn't.
> 
> You need to check first if the bug is in QEMU or the vhost-user-blk server.
>
  Thanks Paolo for your comments, and i will do it later. thanks!

  Yang

> Paolo