Re: [PATCH v7 00/42] guest_memfd: In-place conversion support

[Sean Christopherson]

On Thu, Jun 04, 2026, Ackerley Tng wrote:
> Sean Christopherson <seanjc@xxxxxxxxxx> writes:
> >> + KVM: selftests: Test conversion with elevated page refcount
> >>     + Askar pointed out that soon vmsplice may not pin pages. Should I
> >>       pin pages through CONFIG_GUP_TEST like in [2]? I prefer not to
> >>       take a dependency on CONFIG_GUP_TEST.
> >
> > I'm not exactly excited about taking a dependency on CONFIG_GUP_TEST either, but
> > it probably is the least awful choice.  E.g. KVM also pins pages is certain flows,
> > but we're _also_ actively working to remove the need to pin.
> >
> > Hmm, maybe IORING_REGISTER_PBUF_RING?  AFAICT, it's almost literally a "pin user
> > memory" syscall.
> >
> 
> Hmm that takes a dependency on io_uring, which isn't always compiled
> in. Between CONFIG_IO_URING and CONFIG_GUP_TEST, I'd rather
> CONFIG_GUP_TEST.

Or try both?  If it's not a ridiculous amount of work.