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Date: Thu, 10 Jul 2025 16:33:28 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Vishal Annapurve <vannapurve@...gle.com>
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Subject: Re: [RFC PATCH v2 00/51] 1G page support for guest_memfd

On Wed, Jul 09, 2025, Vishal Annapurve wrote:
> On Wed, Jul 9, 2025 at 8:00 AM Sean Christopherson <seanjc@...gle.com> wrote:
> >
> > On Wed, Jul 09, 2025, Vishal Annapurve wrote:
> > > I think we can simplify the role of guest_memfd in line with discussion [1]:
> >
> > I genuinely don't understand what you're trying to "simplify".  We need to define
> > an ABI that is flexible and robust, but beyond that most of these guidelines boil
> > down to "don't write bad code".
> 
> My goal for bringing this discussion up is to see if we can better
> define the role of guest_memfd and how it interacts with other layers,
> as I see some scenarios that can be improved like kvm_gmem_populate[1]
> where guest_memfd is trying to fault in pages on behalf of KVM.

Ah, gotcha.  From my perspective, it's all just KVM, which is why I'm not feeling
the same sense of urgency to formally define anything.  We want to encapsulate
code, have separate of concerns, etc., but I don't see that as being anything
unique or special to guest_memfd.  We try to achieve the same for all major areas
of KVM, though obviously with mixed results :-)

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