On 14/05/2015 14:00, Christoffer Dall wrote: > So, getting back to my original question. Is the point then that UEFI > must assume (from ACPI/DT) the cache-coherency properties of the PCI > controller which exists in hardware on the system you're running on, > even for the virtual PCI bus because that will be the semantics for > assigned devices? > > And in that case, we have no way to distinguish between passthrough > devices and virtual devices plugged into the virtual PCI bus?
Well, we could use the subsystem id. But it's a hack, and may cause incompatibilities with some drivers. Michael, any ideas? > What about the idea of having two virtual PCI buses on your system where > one is always cache-coherent and uses for virtual devices, and the other > is whatever the hardware is and used for passthrough devices? I think that was rejected before. Paolo
