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

[Tian, Kevin]

> From: Kalra, Ashish [mailto:address@hidden
> Sent: Friday, July 7, 2017 7:24 AM
> 
> 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.

yes, that's a necessary part to support SVM in both virtio-iommu 
approach and fully emulated approach (e.g. for Intel VTd). There
are already patches and discussions in other thread about how to
propagate IOMMU page fault to vIOMMU. Then after it is done
vIOMMU page fault emulation will be further added.

https://lkml.org/lkml/2017/6/27/964

Thanks
Kevin