Re: [PATCH v9 07/41] KVM: guest_memfd: Wire up core private/shared attribute interfaces

[Sean Christopherson]

 On Mon, Aug 03, 2026, Xiaoyao Li wrote:
> On 8/1/2026 12:26 AM, Sean Christopherson wrote:
> > On Fri, Jul 31, 2026, Xiaoyao Li wrote:
> > > On 7/31/2026 4:42 AM, Ackerley Tng wrote:
> > > If kvm_range_is_private() is useful/required by huge page support, then let
> > > the huge page series to introduce it. It has nothing to do with the in-place
> > > conversion series.
> > 
> > If it weren't for the fact that the range-based search is used later in this
> > series, I would 100% agree with Xiaoyao.
> > But since the core logic is used and needed elsewhere,
> 
> I don't see it a problem. Without introducing kvm_range_is_private() in this
> patch, the core logic of range-based search on gmem can still be introduced
> as kvm_gmem_range_has_attributes() directly in patch 10 or in a separate
> patch.
> 
> > and because kvm_range_has_vm_memory_attributes() takes a range, my vote is
> > to provide the plumbing now, even though a small portion of it isn't
> > strictly necessary.
> 
> So my initial feedback was "we can just use kvm_mem_is_private(kvm, gfn)".
> It makes code simpler.

My apologies, I hadn't actually applied v9 to look at the full context.  I agree,
providing kvm_range_is_private() is completely unnecessary.  It's not even really
a problem with this patch, it's a pre-existing issue that can and should be
addressed with a prep patch.

> And as a bonus, the logic to choose between gmem-based attribute query and
> vm-based attribute query is hidden from the static call.

I don't follow.  What do you mean by "hidden from the static call?"  The whole
point of using a static call is to select between gmem-based and vm-based private
memory.  Or are you saying the populate() flow doesn't need to manually check
gmem_in_place_conversion?

> The second bonus of dropping kvm_range_is_private() is that we can eliminate
> one more chunk in patch 20.

Ya.

Untested, but unless I'm missing something, patches 6 and 7 of this series can
be replaced with the attached patches (6 and 7 should be squashed together no
matter what).