Hi, > > Given newer processors have more than 40 and for older ones we know > > the possible values for the two relevant x86 vendors we could do > > something along the lines of: > > > > phys-bits >= 41 -> valid > > phys-bits == 40 + AuthenticAMD -> valid > > phys-bits == 36,39 + GenuineIntel -> valid > > everything else -> invalid > > > > Does that look sensible to you? > > > > Yes, it does! Is phys-bits == 36 the same as invalid? 'invalid' would continue to use the current guesswork codepath for phys-bits. Which will end up with phys-bits = 36 for smaller VMs, but it can go beyond that in VMs with alot (32G or more) of memory. That logic assumes that physical machines with enough RAM for 32G+ guests have a physical address space > 64G. 'phys-bits = 36' would be a hard limit. So, it's not exactly the same but small VMs wouldn't see a difference. take care, Gerd
