Linux Kernel Artifacts

This directory builds the Linux boot artifacts used by vz-linux:

• out/vmlinux
• out/initramfs.img
• out/youki
• out/version.json

Quick start

make -C linux all

If your host toolchain does not have ARM64 + musl cross support:

make -C linux docker-build

Benchmark boot latency

cd crates
cargo run -p vz-linux --bin vz-linux-bench -- \
  --bundle-dir ../linux/out \
  --iterations 10 \
  --timeout-secs 8 \
  --guest-logs \
  --http-smoke-url http://example.com/

Useful benchmark flags:

• --guest-logs captures dmesg | tail -n 120 after each run.
• --http-smoke-url URL runs a curl-like HTTP smoke check in guest via BusyBox wget.
• --guest-log-command "..." captures a custom guest command via sh -lc.
• --retry-log-every N prints a readiness heartbeat every N retries.
• --rootfs-dir PATH mounts a host rootfs directory via VirtioFS tag rootfs and benchmarks overlay+chroot rootfs boot mode.

Inputs

• vz-linux.config kernel config fragment
• initramfs/ template files (init, resolv.conf, udhcpc.script)
• crates/vz-guest-agent binary (cross-compiled for Linux)

Output compatibility

version.json includes guest-agent and pinned youki version metadata. vz-linux::ensure_kernel() uses this to reject mismatched artifact sets, and verifies SHA256 checksums when present.