On Mon, Jan 25, 2021 at 08:34:29PM -0700, Alex Williamson wrote: > > someting like this was already tried in May and didn't go anywhere - > > are you surprised that we are reluctant to commit alot of resources > > doing a complete job just to have it go nowhere again? > > That's not really what I'm getting from your feedback, indicating > vfio-pci is essentially done, the mlx stub driver should be enough to > see the direction, and additional concerns can be handled with TODO > comments. I think we are looking at this RFC in different ways. I see it as largely "done" showing the general design of few big ideas: - new vfio drivers will be creating treating VFIO PCI as a "VFIO bus driver" library - These new drivers are PCI devices bound via driver core as peers to vfio-pci, vs sub drivers of vfio-pci - It uses the subsystem -> driver -> library pattern for composing drivers instead of the subsystem -> midlayer -> driver pattern mdev/platform use - It will have some driver facing API from vfio-pci-core that is close to what is shown in the RFC - The drivers can "double bind" in the driver core to access the PF resources via aux devices from the VF VFIO driver. The point of a RFC discussion is to try to come to some community understanding on a general high level direction. It is not a perfectly polished illustration of things that shouldn't be contentious or technically hard. There are alot of things that can be polished here, this illustration has lots of stuff in vfio-pci-core that really should be in vfio-pci - it will take time and effort to properly split things up and do a great job here. > Sorry if this is not construed as actual feedback, I think both > Connie and I are making an effort to understand this and being > hampered by lack of a clear api or a vendor driver that's anything > more than vfio-pci plus an aux bus interface. Thanks, I appreciate the effort, and there is a lot to understand here. Most of this stuff is very new technology and not backed by industry standards bodies. I really do think this simplified RFC will help the process - I've seen the internal prototype and it is a mass of opaque device specific code. Max's V2 should flesh things out more. Thanks, Jason
