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

Sean Christopherson <[email protected]> Mon, 10 Aug 2026 15:58:20 -0700

Newsgroups	dev.linux.lists.kvmarm,org.infradead.lists.kexec,org.kernel.vger.kvm,org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest,org.kvack.linux-mm
Message-ID	<[email protected]>

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.