Sets the virtual machine background processes priority.
PRL_RESULT PrlVmCfg_SetBackgroundPriority( PRL_HANDLE hVmCfg, PRL_VM_PRIORITY nVmBackgroundPriority );
PrlApiVm.h
PRL_RESULT. Possible values:
PRL_ERR_INVALID_ARG - invalid handle or null pointer was passed.
PRL_ERR_SUCCESS - function completed successfully.