It doesn't require a VM pause to cause a system freeze, an SMI interrupt can do that as well. It doesn't take a lot to have backwards time travel, NTP can do t

It doesn't require a VM pause to cause a system freeze, an SMI interrupt can do that as well. It doesn't take a lot to have backwards time travel, NTP can do that for you as well in some bad configurations. It's very hard to rely on time in a distributed system. If you want a simple algorithm just don't rely on time at all, use it for logs so a human can correlate things when debugging an issue but don't assume time will flow at the same rate for all systems. Do use a monotonic clock always for internal timers, time does move backwards in systems.