Appendix G. KVM Virtual Machine Timing Management

http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Virtualization/3.0/html/Administration_Guide/KVM_Clock_Appendix.html

Summary: append to VM’s kernel, for i386,i686 => ‘divider=10 clocksource=acpi_pm’, for x86_64 => ‘divider=10 notsc’ This is needed to fix the drifting clock issue on VMs that are not using pv_clock driver