[PATCH v4 01/11] liveupdate: Add LIVEUPDATE_GUEST_MEMFD config option

[Sean Christopherson]

On Tue, Jul 28, 2026, Tarun Sahu wrote:
> Introduce the LIVEUPDATE_GUEST_MEMFD Kconfig option. This option
> enables live update support for KVM guest_memfd files, enabling
> guest_memfd-backed memory preservation across kernel upgrades.
> 
> Currently this support only guest_memfd files that are full-shared
> (INIT_SHARED and no support for private_mem).

Why?  Specifically, why do we need/want a separate Kconfig for guest_memfd
liveupdate versus KVM liveupdate?  I can _maybe_ see a KVM-wide Kconfig, but
even that seems like a stretch given that (AFAIK) hypervisors are the one and
only use-case for liveupdate.