Re: [Qemu-devel] [PATCH RFC] fixup! virtio: convert to use DMA api

[Michael S. Tsirkin]

On Tue, Apr 19, 2016 at 12:26:44PM -0400, David Woodhouse wrote:
> On Tue, 2016-04-19 at 19:20 +0300, Michael S. Tsirkin wrote:
> > 
> > > I thought that PLATFORM served that purpose.  Woudn't the host
> > > advertise PLATFORM support and, if the guest doesn't ack it, the host
> > > device would skip translation?  Or is that problematic for vfio?
> > 
> > Exactly that's problematic for security.
> > You can't allow guest driver to decide whether device skips security.
> 
> Right. Because fundamentally, this *isn't* a property of the endpoint
> device, and doesn't live in virtio itself.
> 
> It's a property of the platform IOMMU, and lives there.

It's a property of the hypervisor virtio implementation, and lives there.

-- 
MST