ESA/390 Interpretive-Execution Architecture, Foundation for VM/ESA

The interpretive-execution facility of Enterprise Systems Architecture/390TM (ESA/390TM) provides an instruction for the execution of virtual machines. This instruction, called START INTERPRETIVE EXECUTION (SIE), was initially created for virtualizing either System/370m or 370-XA architectures and was used later for virtualizing ESA/370' and ESA/390 architectures. SIE has evolved to provide capabilities for a number of specialized performance environments. Most recently it provides for the unique requirements of Enterprise Systems Architecture/Extended Configuration (ESA/XC) virtual-machine architecture. This comprehensive set of capabilities in the architecture serves as the platform for the ability of VM/ESAm to provide functions in virtual machines for end users and system servers. This paper describes the evolution of SIE and outlines use of the various capabilities in VM/ESA. product uses the ESA/39OTM interpretive-execution facility',* to establish the virtual-machine environment. In this environment, the processor directly executes most of the functions of the virtual machine.