Re: [PATCH v7 00/14] KVM: mm: fd-based approach for supporting KVM guest private memory

[Gupta, Pankaj]

> > > Actually the current version allows you to delay the allocation to a
> > > later time (e.g. page fault time) if you don't call fallocate() on the
> > > private fd. fallocate() is necessary in previous versions because we
> > > treat the existense in the fd as 'private' but in this version we track
> > > private/shared info in KVM so we don't rely on that fact from memory
> > > backstores.
> >
> > Does this also mean reservation of guest physical memory with secure
> > processor (both for SEV-SNP & TDX) will also happen at page fault time?
> >
> > Do we plan to keep it this way?
>
> If you are talking about accepting memory by the guest, it is initiated by
> the guest and has nothing to do with page fault time vs fallocate()
> allocation of host memory. I mean acceptance happens after host memory
> allocation but they are not in lockstep, acceptance can happen much later.

No, I meant reserving guest physical memory range from hypervisor e.g 
with RMPUpdate for SEV-SNP or equivalent at TDX side (PAMTs?).

Thanks,
Pankaj