1. A computer program product for a configuration change of a topology of a plurality of first processors (CPUs) of a first configuration, the computer program product comprising a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: executing a perform topology function instruction, the execution comprising: any one of initiating a change of the polarization of the processors of the guest configuration according to the requested polarization change or rejecting the polarization change request; and responsive to the initiating the change of the polarization of the processors of the guest configuration, setting a condition code to a value indicating a polarization change is initiated.