pvm

Guest kernel

guest/build.sh produces vmlinux-pvm-amd64: an uncompressed, module-free, PVH-bootable ELF kernel that Cloud Hypervisor loads via --kernel, exactly like sandbox’s standard guest kernel.

Config composition

Applied in order on the pinned tree:

1. x86_64_defconfig + kvm_guest.config — upstream baselines
2. configs/guest-base.config — derived from sandbox/boot/kernel/sandbox.config (kept in sync by hand): everything the boot path touches built in, no modules, the sandbox trim cuts
3. configs/guest-pvm.config — the PVM delta: CONFIG_X86_PIE=y, CONFIG_PVM_GUEST=y, 5-level paging off

After olddefconfig the build asserts the PVM, boot- and container-critical symbols survived the merge — merge_config only warns, and a silently dropped symbol must fail the build, not ship.

Notes

• The PVM tree is Linux 6.12 LTS while sandbox’s standard kernel tracks a newer series; the two artifacts are parallel, not interchangeable.
• configs/upstream/pvm-guest-6.12.33.config is virt-pvm’s own reference config, vendored for diffing. It still lists CONFIG_RELOCATABLE_UNCOMPRESSED_KERNEL, which no longer exists on pvm-612 — the PIE relocation mechanism changed during the 6.12 rebase. Do not assert on it.
• Because the guest kernel arrives via --kernel and carries no modules, existing os-images need no changes to run under PVM.

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