Virtual Machines

In the realm of computing, a virtual machine (VM) represents the virtualization or emulation of a computer system. These machines are architected based on various computer architectures and enable the execution of an entire operating system on top of another one, effectively creating an isolated environment where multiple operating systems can run concurrently on a single physical machine.

Types of Virtual Machines

System Virtual Machines

A system virtual machine, also referred to as a full virtualization VM or SysVM, provides a comprehensive system platform that supports the execution of an entire operating system (OS). The core enabling technology for SysVMs is the hypervisor, also known as the virtual machine monitor (VMM). Hypervisors utilize native execution to manage and allocate hardware resources, allowing multiple isolated environments to coexist on the same physical machine.

Process Virtual Machines

A process virtual machine is designed to execute a single program or process. The most prominent example is the Java Virtual Machine (JVM), which enables computers to run Java programs as well as those written in other languages that are compiled to Java bytecode.

Virtual Machine Emulators

Virtual machine emulators, such as QEMU and other video game console emulators, are designed to mimic different system architectures. This enables software applications and operating systems written for one CPU architecture to run on another, providing a powerful tool for software development and testing.

Virtualization

The broader concept of virtualization encompasses a series of technologies that divide physical computing resources into a series of virtual machines. This technology is fundamental to modern computing environments, especially in cloud computing, where resources are dynamically allocated and managed.

Security and Virtual Machines

In the realm of computer security, concerns such as virtual machine escape are of paramount importance. This refers to the process by which a program breaks out of the virtual environment, potentially compromising the host system. Virtual machine introspection (VMI) is a technique employed to monitor the runtime state of system-level virtual machines, enhancing security by providing visibility into the VM's operations.

Applications in Blockchain

Virtual machines are also pivotal in blockchain technology. The Ethereum Virtual Machine (EVM) is integral to Ethereum, a blockchain platform. The EVM facilitates the execution of smart contracts, enabling decentralized applications within the Ethereum network.

Virtual Machine