Re: [Qemu-devel] [PATCH 08/10] intel-iommu: maintain per-device iova ranges

[Jason Wang]

On 2018年05月03日 14:04, Peter Xu wrote:
> IMHO the guest can't really detect this, but it'll found that the
> device is not working functionally if it's doing something like what
> Jason has mentioned.
>
> Actually now I have had an idea if we really want to live well even
> with Jason's example: maybe we'll need to identify PSI/DSI.  For DSI,
> we don't remap for mapped pages; for PSI, we unmap and remap the
> mapped pages.  That'll complicate the stuff a bit, but it should
> satisfy all the people.
>
> Thanks,

So it looks like there will be still unnecessary unamps. How about 
record the mappings in the tree too?

Thanks