Re: [RFC PATCH 0/3] KVM: Dirty page logging for guest_memfd-only memslots

[David Hildenbrand <david.hildenbrand@arm.com>]

>> That said, odds are good that we'll end up with per-gmem flags to communicate to
>> guest_memfd whether or not the gmem instance supports page migration (x86's TDX
>> and SNP in particular require extra consideration).  So if the anticipated use
>> cases are fine with all-or-nothing "pinning", or with juggling guest_memfd files
>> in userspace if a more dynamic setup is desired, then you should be ok?
>>
>> E.g. if the anticipated use cases are all slice-of-hardware style setups where
>> the VM will be statically assigned a chunk of memory, then for the most part this
>> will all Just Work.
> 
> Yeah. I agree (with the caveats you mention). Arm folk need to go figure
> out if it's worthwhile to support with all those caveats.

Right, disabling migration (once gmem supports it) was also what I discussed
with Alexandru when that topic comes up.

How to communicate to gmem that it wants these fixed mappings is a good question.

-- 
Cheers,

David