Re: [Qemu-arm] [Qemu-devel] [RFC v2 0/8] VIRTIO-IOMMU device

[Michael S. Tsirkin]

On Thu, Jul 06, 2017 at 11:23:41PM +0000, Kalra, Ashish wrote:
> I have a generic question on vIOMMU support, is there any proposal/plan to 
> add ATS/PRI extension support to vIOMMUs and allow
> handling for end to end (v)IOMMU Page faults (w/t the device side 
> implementation on Vhost) ?
> 
> Again, the motivation will be to do DMA on paged guest memory and potentially 
> avoiding the requirement of pinned/locked
> guest physical memory for DMA.
> 
> Thanks,
> Ashish

If that's your goal, first step would be support in VFIO.
End to end would only be helpful when running userspace
drivers within guest, or nested virt.

-- 
MST