TSC cleanups, fixes, documentation for KVM

Zachary Amsden
2010-06-15T07:34:02Z

This is an attempt to cleanup and plug some of the many existing holes
with TSC and as a direct result, kvmclock. It is not a perfect attempt;
no trap and emulate is yet done for TSC in cases in which it can not be
perfectly virtualized. In particular, on platforms with unstable /
buggy TSCs, it is not possible to even get a perfectly synchronized TSC.
TSC virtualization should be much improved and many bugs with suspend,
cpufreq as well as general synchronization errors will be eliminated.