After migrating from RHEL7 to RHEL8, VMware VMs experience inexplicable low CPU performance

Issue

• After migrating from RHEL7 to RHEL8, VMware VMs experience inexplicable low CPU performance.

CPU bad VM:
real    0m1.867s
user    0m1.703s
sys     0m0.158s

CPU normal VM:
real    0m0.838s
user    0m0.707s
sys     0m0.131s

• At one point, instead of simply rebooting the VMs experiencing poor performance, we decided to shut them down first and then power them on again. Essentially, we performed the equivalent of a power cycle on these VMs.
• Surprisingly, immediately afterward, the performance issues were resolved as if by magic.
• The last machine where we could see the issue is no longer having the problem. This is most likely due to a migration activity that took place on vmware level. This time the migration took place on a powered on machine, and also resolved the problem.