On Thu, Aug 7, 2014 at 5:13 PM, Valeri Galtsev <galtsev at kicp.uchicago.edu> wrote: > >>> >>> ... And in addition to that, I need to have a 64-bit OS running on it, >>> which I apparently don't. Just my luck. :-( >>> >> >> Technically you don't need to have a 64-bit host OS to virtualize a >> 64-bit guest but that may be the way kvm is built. I know I used to >> run 64-bit linux versions under vmware player on a laptop running >> 32-bit windows XP. Maybe virtualbox would work... > > To the best of my knowledge, vmware emulates generic CPU, therefore, guest > can have different architecture from host. Emulates meaning, in > particular, what is CPU register for guest is actually sitting in RAM. > Therefore, regisetr-to-register operation for vmware guest ias asctually > physical RAM to physical RAM operation which is a couple of orders on > magnitude slower (well, was long ago, and I'm sure still is). I don't think that makes any sense in the context of CPU's with hardware virtualization capability - which is necessary for 64-bit guests anyway. And it doesn't match the speeds I've observed for vmware vs kvm guests which seem about the same. It might be true when running 32 bit guests on hosts where the CPU does not have hardware virtualization support. -- Les Mikesell lesmikesell at gmail.com