[libvirt] Supporting hypervisor specific APIs in libvirt

Hi, I've mentioned this to a few folks already but I wanted to start a proper thread. We're struggling in qemu with usability and one area that concerns me is the disparity in features that are supported by qemu vs what's implemented in libvirt. This isn't necessarily libvirt's problem if it's mission is to provide a common hypervisor API that covers the most commonly used features. However, for qemu, we need an API that covers all of our features that people can develop against. The ultimate question we need to figure out is, should we encourage our users to always use libvirt or should we build our own API for people (and libvirt) to consume. I don't think it's necessarily a big technical challenge for libvirt to support qemu more completely. I think it amounts to introducing a series of virQemuXXXX APIs that implement qemu specific functions. Over time, qemu specific APIs can be deprecated in favour of more generic virDomain APIs. What's the feeling about this from the libvirt side of things? Is there interest in support hypervisor specific interfaces should we be looking to provide our own management interface for libvirt to consume? Regards, Anthony Liguori