On Mon, Dec 14, 2009 at 02:18:33PM -0600, Anthony Liguori wrote: > Michael S. Tsirkin wrote: >> This might help 32 bit guests, but not guests with 64 bit >> kernel and 32 bit userspace (my case) because all 64 bit >> CPUs advertise syscall bit in cpuid. Thus 64 bit guests >> do not seem to even bother checking this bit: >> AMD + 64 bit -> syscall. >> > > Okay, I don't see a great option other than migrating the vendor_id string.
This won't help with kernels <2.6.32 though. I guess we can switch default vendor to Intel, this likely has some other side effects. > Otherwise, cross vendor migration will not work by default. Maybe > that's not a problem but if so, we really should change the default cpu > model to be much more aggressive about exposing host features. > > Regards, > > Anthony Liguori It's a tradeoff, but yes. We also need more sanity checks and management commands giving management tools to understand whether emulating guest CPU X on host CPU Y is safe/possible, and which guests this might break. -- MST
