For many years the QEMU codebase has contained PV backends for Xen guests, giving them paravirtual access to storage, network, keyboard, mouse, etc. however these backends have not been configurable as QEMU devices as their implementation did not fully adhere to the QEMU Object Model (QOM).
Particularly the PV storage backend not using proper QOM devices, or qdevs, meant that the QEMU block layer needed to maintain legacy code that was cluttering up the source. This was causing push-back from the maintainers who did not want to accept any patches relating to that Xen backend until it was 'qdevified'.
In this talk, I'll explain the modifications I made to QEMU to achieve 'qdevification' of the PV storage backend, how compatibility with the libxl toolstack was maintained, and what the next steps in both QEMU and libxl development should be.
