Re: [PATCH v2] vhost: introduce mdev based hardware backend

From: Jason Wang
Date: Fri Oct 25 2019 - 05:55:19 EST

On 2019/10/24 äå6:42, Jason Wang wrote:


 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.


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.