Incorrect data(CPU utilization) for KVM and Host in CentOS 7

[MyungChi]

I test with Host sFlow as below environment.

• Host OS : CentOS 7.3 with KVM (4 core)
• Guest OS : CentOS 7.3 ( 2 vcore )
• hsflowd-2.0.15-1.x86_64 is installed in Host OS

I generate overhead with stress tool. (yum install stress)

• Guest OS CPU is shown 50% with top.
• Host OS CPU is shown 25% with top.

I checked with sflowtool collected counter information from hsflowd.

In case of Host OS cpu_load_one 1.320 cpu_load_five 1.330 cpu_load_fifteen 1.090

In case of Guest OS delta of CPU time(30 sec) = 1060630 - 1095300 = 69340 69340 / 30000 = 2.315

Is this collect ? I can't sure is it right way to get CPU utilization.