Thanks to Michael Meier and Robert C.
After modify grub cmd parameters "nohz=off highres=off", all is well!
Host: Centos7
Guest: Centos7
I'm a kvm host provider, I have same problem!
Even 35% of all my 72 cores in cpu system computing.
@PoempelFox
Do you have a solution such as change some options in kvm xml?
Thanks to Michael Meier and Robert C.
After modify grub cmd parameters "nohz=off highres=off", all is well!
Host: Centos7
Guest: Centos7