On 2019/10/24 下午6:42, Jason Wang wrote:

Yes.

quoted

  And we should try to avoid
putting ctrl vq and Rx/Tx vqs in the same DMA space to prevent
guests having the chance to bypass the host (e.g. QEMU) to
setup the backend accelerator directly.

That's really good point.  So when "vhost" type is created, parent 
should assume addr of ctrl_vq is hva.

Thanks

This works for vhost but not virtio since there's no way for virtio 
kernel driver to differ ctrl_vq with the rest when doing DMA map. One 
possible solution is to provide DMA domain isolation between virtqueues. 
Then ctrl vq can use its dedicated DMA domain for the work.

Anyway, this could be done in the future. We can have a version first 
that doesn't support ctrl_vq.

Thanks