Virtual machine system with vitual machine resetting store indicating that virtual machine processed interrupt without virtual machine control program intervention

Claim 1

A virtual machine system having a virtual machine, a virtual machine control program, said virtual machine selectively processing input/output (I/O) interruptions with and without intervention of said virtual machine control program when said virtual machine is set to non-interruptible and interruptible states respectively, and instruction processor means connected to main storage means, said system comprising: hardware subchannel means included in said main storage means; storage means, provided in said hardware subchannel means, or indicating by a set condition that an I/O interruption has been accepted and reserved by a virtual machine control program regardless of whether said virtual machine is interruptible; reset means, provided in said instruction processor means, coupled to said store means, operative when said virtual machine is set to the non-interruptible state and has processed interruption information without an intervention of the virtual machine control program, for resetting said store means; monitor and control means, provided in said instruction processor means, coupled to said store means, for permitting the virtual machine control program to control said system when the virtual machine is set to the interruptible state and said store means indicted a set condition; and test means, provided in said instruction processor means, coupled to said store means, for determining whether the virtual machine has reset said store means.