Package: src:linux
Version: 7.2.7-1
Severity: wishlist

Please consider enabling the following options in Debian kernel builds on 
architectures that support them (in particular amd64 and arm64):

CONFIG_KEXEC_HANDOVER=y
CONFIG_KEXEC_HANDOVER_ENABLE_DEFAULT=n
CONFIG_LIVEUPDATE=y
CONFIG_LIVEUPDATE_MEMFD=y

The default-off setting is intentional. Kexec Handover should remain opt-in 
through the kho=on kernel parameter; Live Update Orchestrator likewise requires 
liveupdate=on. This makes the facilities available without changing the default 
behavior or requiring users to rebuild Debian kernels.

Our use case is a stateful service that stores application state in memfds held 
by systemd's file descriptor store. That state includes many UDP connection 
contexts. With KHO and LUO, a new kernel and service instance can recover the 
same memfd-backed state across kexec. This does not require the kernel to 
preserve the UDP sockets themselves. We have exercised the handover with a 
custom 7.2.7 kernel in a Debian sid KVM guest; stock Debian kernels do not 
currently expose these options.

The options are provided upstream and remain gated by the required architecture 
and feature dependencies. Enabling them in Debian would let interested users 
test and deploy this mechanism explicitly, while leaving normal boots unchanged.

Upstream documentation: https://docs.kernel.org/core-api/liveupdate.html

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