How does that matter, if we are able to standardize all this then,
hypervisors which want to run a Linux guest should effectively play by
the standards over here or else they would never work properly on Linux.
What we are trying to do here is try to standardize things for Linux so
that the Linux kernel implementation for Virtualization is that much
more easier. If this goes well other closed source hypervisors too can
effectively follow these standards. If the other closed source hypervisors define their own cpuid leafs they
will still have to make Linux kernel side changes to make use of these
new leafs. Which allows them to add to these pool of cpuid interface's
too.