Maintaining compatibility for complex functions over multiple machine generations

A method comprising:

• executing a first virtual machine and a virtual architecture level by a first generation machine of a plurality of machines, the plurality of machines comprising the first generation machine and a second generation machine, each of the plurality of machines comprising a machine version;
• executing a second virtual machine and the virtual architecture level by the second generation machine;
• and
• providing, by the virtual architecture level, a compatibility level for a complex interruptible instruction to the first and second virtual machines, the compatibility level being architected for a lowest common denominator machine version across the plurality of machines, the compatibility level comprising a lowest common denominator indicator identifying the lowest common denominator machine version.

A computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable to cause operations comprising:

• executing a first virtual machine and a virtual architecture level by a first generation machine of a plurality of machines, the plurality of machines comprising a first generation machine and a second generation machine, each of the plurality of machines comprising a machine version;
• executing a second virtual machine and the virtual architecture level by the second generation machine;
• and
• providing, by the virtual architecture level, a compatibility level for a complex interruptible instruction to the first and second virtual machines, the compatibility level being architected for a lowest common denominator machine version across the plurality of machines, the compatibility level comprising a lowest common denominator indicator identifying the lowest common denominator machine version.

A method comprising:

• implementing a complex interruptible instruction by a first machine;
• indicating in a virtual architecture level that a parameter block of the first machine is supported for the complex interruptible instruction;
• and
• propagating the parameter block of the first machine to each virtual machine running in a complex.

A computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable to cause operations comprising:

• implementing a complex interruptible instruction by a first machine;
• indicating in a virtual architecture level that a parameter block of the first machine is supported for the complex interruptible instruction;
• and
• propagating the parameter block of the first machine to each virtual machine running in a complex.