Re: [PATCH 5/5] virtio: Add bounce DMA ops

Konrad Rzeszutek Wilk
2020-04-30T15:20:03Z

On Wed, Apr 29, 2020 at 06:20:48AM -0400, Michael S. Tsirkin wrote:
> On Wed, Apr 29, 2020 at 03:39:53PM +0530, Srivatsa Vaddagiri wrote:
> > That would still not work I think where swiotlb is used for pass-thr devices
> > (when private memory is fine) as well as virtio devices (when shared memory is
> > required).
>
> So that is a separate question. When there are multiple untrusted
> devices, at the moment it looks like a single bounce buffer is used.
>
> Which to me seems like a security problem, I think we should protect
> untrusted devices from each other.

There are two DMA pools code in Linux already - the TTM one for graphics
and the mm/dmapool.c - could those be used instead? Or augmented at least?