.monster snip.. > 4. Using CPUID to detect running as guest. But as Thomas pointed out, this > approach is less reliable as not all hypervisors do this way. Is that truly true? It is the first time I see the argument that extra steps are needed and that checking for X86_FEATURE_HYPERVISOR is not enough. Or is it more "Some hypervisor probably forgot about it, so lets make sure we patch over that possible hole?" Also is there anything in this spec that precludes this from working on non-X86 architectures, say ARM systems?