This project presents a first working state for live migration of bhyve guests on FreeBSD 15.1. A running amd64 guest can move between two hosts over TCP while continuing to run; it is paused only for the final stop-and-copy phase. The work builds on bhyve's experimental snapshot support and adds dirty-page tracking in the vmm kernel module together with a migration protocol in bhyve and bhyvectl.
I previously discussed the state of bhyve live migration, its historical development, existing limitations, and why it matters for the future of FreeBSD virtualization in my article bhyve on FreeBSD and VM Live Migration – Quo vadis?.
The goal is deliberately practical: make it possible to test, discuss, and improve a real implementation rather than discuss live migration only in the abstract. The current code and test tooling are being published as a WIP RFC so that the next steps can be shaped in the open. A more detailed demonstration of a VM being live migrated can be watched on my YouTube channel.
