Virtual machine I/O interrupt control method compares number of pending I/O interrupt conditions for non-running virtual machines with predetermined number

摘要

A virtual machine system controls the operation of a plurality of virtual machines on a single computer and permits the computer to be switched from one virtual machine to another for carrying out urgent input/output operations. The decision to switch from an operating virtual machine to one of a plurality of other non-operating virtual machines is based on examining the number of input/output interrupt conditions that occur for each virtual machine other than the running one. When the number of input/output interrupt conditions for a virtual machine other than the running one is found to exceed a predetermined threshold number, operation of the currently running virtual machine is suspended. Control of the computer is then returned to the virtual machine control system to permit execution of another virtual machine so that the input/output interrupt condition for that virtual machine can be acknowledged.