> If you are ever going to migrate to Skylake, I think you should just > always tell the guests that you're running on Skylake. That way the > guests will always assume the worst case situation wrt Specte. Unfortunately if you do that then guest may also decide to use other Skylake hardware features and pop its clogs when it finds out its actually running on Westmere or SandyBridge. So you need to be able to both lie to the OS and user space via cpuid and also have a second 'but do skylake protections' that only mitigation aware software knows about. Alan
