Multiprocessing system including gating of host I/O and external enablement to guest enablement at polling intervals

Abstract

A data processing system operating under a multiprocessing hypervisor program subject to I/O interrupts during a polling interval of the hypervisor program includes one or more processors for executing the hypervisor program and host system and one or more guest systems under the hypervisor program, a storage system connected to the processor's by a bus for storing instructions, data and control information associated with the systems being executed by the processor, the storage system may be partitioned into a number of separate areas each associated with one of the concurrently operating systems, an input/output subsystem for generating I/O interrupts to the processors, apparatus for testing to determine if the system is operating in an interpretive execution mode, apparatus for determining whether a dedicated region facility is active, apparatus for testing whether an I/O enablement mask for a guest system has been set, apparatus for setting a flag if the guest system I/O enablement mask is set, apparatus for testing the flag during each polling interval of the interpretive execution mode, apparatus for loading a control byte from a host control register into a hardware register if the flag has not been set and a count threshold reached, apparatus for testing for host system I/O interrupts and apparatus for switching to the host system if the host system interrupt is present.

Dependencies are inferred from the claim text.