Paravirtual steal time accounting

configname: CONFIG_PARAVIRT_TIME_ACCOUNTING

Linux Kernel Configuration
└─>Processor type and features
└─>Paravirtualized guest support
└─>Paravirtual steal time accounting
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Select this option to enable fine granularity task steal time
accounting. Time spent executing other tasks in parallel with
the current vCPU is discounted from the vCPU power. To account for
that, there can be a small performance impact.

If in doubt, say N here.