4.C) Discuss the machine reference model of execution virtualization. – 6 Marks
Answer:-
The machine reference model is a framework used to understand how virtualization interacts with different layers of a computing system. It defines the interfaces between various levels of abstraction and clarifies how virtualization techniques operate by replacing specific layers and intercepting calls intended for them.
Layers of the Machine Reference Model:
The reference model in modern computing systems consists of several abstraction layers, which simplify the interaction between software and hardware:
- Instruction Set Architecture (ISA):
- This is the lowest level of the model and represents the interface between the hardware and software.
- The ISA defines the processor’s instruction set, registers, memory, and interrupt management, making it the foundational layer for all operations in the computing system.
- It is crucial for OS developers (System ISA) and application developers (User ISA) to understand the ISA for managing and interacting with hardware.
- Application Binary Interface (ABI):
- The ABI acts as an intermediary between the operating system and applications. It covers low-level details like data types, alignment, and call conventions.
- The ABI defines how application programs interface with the operating system, providing portability for applications and libraries across different OS implementations.
- Application Programming Interface (API):
- At the highest abstraction level, the API provides an interface for applications to interact with libraries and the operating system.
- The API handles high-level operations and translates them into lower-level machine instructions through the ABI and ISA, which are responsible for the execution of the instructions.
