Hi, > > I don't see a need for that. Live migration compatibility can be > > handled just fine today using > > 'host-phys-bits=on,host-phys-bits-limit=<xx>' > > > > Which is simliar to 'phys-bits=<xx>'. > > yes but what if user did not configure anything? I expect that'll be less and less common. The phys-bits=40 default used by qemu becomes increasingly problematic for large guests which need more than that, and we see activity implementing support for that in libvirt. > the point of the above is so we can eventually, in X years, change the guests > to trust CPUID by default. Well, we can flip host-phys-bits to default to 'on' in qemu for new machine types (or new cpu versions). That'll have the very same effect. take care, Gerd
