> > In validating QEMU migration compatibility we merely compare the > > versioned machine type. > > Thinking more about this, maybe the big picture is: > > Today the managment tool controls the variables in the migration (the > device configuration). It has knowledge of the VMM, can set a machine > type, apply a device configuration on top, and then migrate safely. > > VFIO changes this model because VMMs and management tools do not have > knowledge of specific device implementations. The device implementation > is a new source of variables in the migration and the management tool no > longer has the full picture.
Well. We actually have the variables. They are device properties. Then the qemu compat properties basically map a machine type to a set of device properties. That way we hide the complexity inside qemu. The management apps have to deal with the (versioned) machine type only. I guess now we have to decide whenever we want expose the individual variables or whenever we want something like "profiles", i.e. basically a set of variables with a name attached. At the end of the day it is a complexity vs. flexibility tradeoff ... take care, Gerd
