A processing system includes physical function circuitry to execute virtual functions and a processing unit configured to operate in a first mode that allows more than one virtual function to execute on the physical function circuitry and a second mode that constrains the physical function circuitry to executing a single virtual function. A first virtual function modifies a state of the processing unit in response to the processing unit being in the second mode. A host driver executing on the processing unit modifies an operating mode indicator to indicate that the processing unit is operating in the first mode or to indicate that the processing unit is operating in the second mode. Microcode executing on the processing unit accesses the operating mode indicator to determine whether the processing unit is operating in the first mode or the second mode.