> IOW, this should be part of the standard migration protocol, not some side
> option that is enabled if the user remembers. It should not be mutually
> exclusive with future migration extensions, including compression.
This is an attractive option. With some polish maybe XBZRLE could be
integrated as a default option that does not degrade performance.
Adding features that require user configuration isn't worthwhile
because they won't be used or they'll be misused - let's not make QEMU
more complicated if it can be avoided.
If there is no way to make XBZRLE automatic then I think it should
live outside QEMU because it will be a niche feature that relatively
few will use but adds complexity to migration.