Symptoms
Your Mac may experience occassional crashes while running Parallels Desktop 8 or Parallels Service Bare Metal at the same time as KVM or Virtual Box.
Cause
This issue is caused by incorrectly working third-party virtualization engines that do not ensure that the virtualization state remains consistent with the state of the actual CPU.
Resolution
For KVM:
Set the KVM module variable "vmm_exclusive" to 0.
for Virtual Box:
No workaround is available. Please try not to use Parallels Desktop and Virtual Box at the same time.