1. A computer program product for managing interruption requests in a computing environment, the computer program product comprising: a computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: responsive to executing a Modify PCI Function Controls (MPFC) instruction register interruptions operation that specifies a function handle of an adapter, specifying a location in system memory of an adapter interruption bit vector (AIBV) of the adapter, the AIBV included in an array of one or more AIBVs, and a location in system memory of an adapter interruption summary bit (AISB) of an AISB array; receiving from the adapter a request for interruption; and responsive to the received request, setting, by an input/output (I/O) hub coupled to the adapter, an indicator in the AIBV indicating a type of event from the adapter and setting the AISB indicating an indicator is set in the AIBV.