Re: [PATCH PROTOTYPE 3/6] vfio: Implement support for sparse RAM memory regions

[Peter Xu]

On Thu, Sep 24, 2020 at 06:04:20PM +0200, David Hildenbrand wrote:
> Implement support for sparse RAM, to be used by virtio-mem. Handling
> is somewhat-similar to memory_region_is_iommu() handling, which also
> notifies on changes.
> 
> Instead of mapping the whole region, we only map selected pieces (and
> unmap previously selected pieces) when notified by the SparseRAMHandler.

It works with vIOMMU too, right? :) As long as vfio_get_vaddr() works as
expected with virtio-mem plugging new memories, then I think the answer should
be yes.

If it's true, maybe worth mention it somewhere either in the commit message or
in the code comment, because it seems not that obvious.

So if you have plan to do some real IOs in your future tests, may also worth
try with the "-device intel-iommu" and intel_iommu=on in the guest against the
same test.

Thanks,

-- 
Peter Xu