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VT-d
x86 virtualization is the use of hardware-assisted virtualization capabilities on an x86/x86-64 CPU. In the late 1990s x86 virtualization was achieved by complex software techniques, necessary to compensate for the processor's lack of hardware-assisted virtualization capabilities while attaining reasonable performance. In 2005 and 2006, both Intel (VT-x) and AMD (AMD-V) introduced limited hardware virtualization support that allowed simpler virtualization software but offered very few speed benefits. Greater hardware support, which allowed substantial speed improvements, came with later processor models. Software-based virtualization The following discussion focuses only on virtualization of the x86 architecture protected mode. In protected mode the operating system kernel runs at a higher privilege such as ring 0, and applications at a lower privilege such as ring 3. In software-based virtualization, a host OS has direct access to hardware while the guest OSs have limited acc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardware-assisted Virtualization
In computing, hardware-assisted virtualization is a platform virtualization approach that enables efficient full virtualization using help from hardware capabilities, primarily from the host processors. A full virtualization is used to emulate a complete hardware environment, or virtual machine, in which an unmodified guest operating system (using the same instruction set as the host machine) effectively executes in complete isolation. Hardware-assisted virtualization was added to x86 processors (Intel VT-x, AMD-V or VIA VT) in 2005, 2006 and 2010 (respectively). Hardware-assisted virtualization is also known as accelerated virtualization; Xen calls it hardware virtual machine (HVM), and Virtual Iron calls it native virtualization. History Hardware-assisted virtualization first appeared on the IBM System/370 in 1972, for use with VM/370, the first virtual machine operating system. With the increasing demand for high-definition computer graphics (e.g. CAD), virtualizatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypervisor
A hypervisor (also known as a virtual machine monitor, VMM, or virtualizer) is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a ''host machine'', and each virtual machine is called a ''guest machine''. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems. Unlike an emulator, the guest executes most instructions on the native hardware. Multiple instances of a variety of operating systems may share the virtualized hardware resources: for example, Linux, Windows, and macOS instances can all run on a single physical x86 machine. This contrasts with operating-system–level virtualization, where all instances (usually called ''containers'') must share a single kernel, though the guest operating systems can differ in user space, such as different Linux distributions with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popek And Goldberg Virtualization Requirements
The Popek and Goldberg virtualization requirements are a set of conditions sufficient for a computer architecture to support system virtualization efficiently. They were introduced by Gerald J. Popek and Robert P. Goldberg in their 1974 article "Formal Requirements for Virtualizable Third Generation Architectures". Even though the requirements are derived under simplifying assumptions, they still represent a convenient way of determining whether a computer architecture supports efficient virtualization and provide guidelines for the design of virtualized computer architectures. VMM definition System virtual machines are capable of virtualizing a full set of hardware resources, including a processor (or processors), memory and storage resources and peripheral devices. A virtual machine monitor (VMM, also called hypervisor) is the piece of software that provides the abstraction of a virtual machine. There are three properties of interest when analyzing the environment created by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VMware
VMware, Inc. is an American cloud computing and virtualization technology company with headquarters in Palo Alto, California. VMware was the first commercially successful company to virtualize the x86 architecture. VMware's desktop software runs on Microsoft Windows, Linux, and macOS. VMware ESXi, its enterprise software hypervisor, is an operating system that runs on server hardware. In May 2022, Broadcom Inc. announced an agreement to acquire VMware in a cash-and-stock transaction valued at $61 billion. History Early history In 1998, VMware was founded by Diane Greene, Mendel Rosenblum, Scott Devine, Ellen Wang and Edouard Bugnion. Greene and Rosenblum were both graduate students at the University of California, Berkeley. Edouard Bugnion remained the chief architect and CTO of VMware until 2005, and went on to found Nuova Systems (now part of Cisco). For the first year, VMware operated in stealth mode, with roughly 20 employees by the end of 1998. The compan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Conference On Architectural Support For Programming Languages And Operating Systems
The International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS) is an annual interdisciplinary computer science conference organized by the Association for Computing Machinery (ACM). Reflecting its focus, sponsorship of the conference is made up of 50% by the ACM's Special Interest Group on Computer Architecture (SIGARCH) and 25% by each of the Special Interest Group on Programming Languages ( SIGPLAN) and the Special Interest Group on Operating Systems ( SIGOPS). It is a high-impact conference in computer architecture and operating systems, but less so in programming languages/software engineering. See also * List of computer science conferences This is a list of academic conferences in computer science. Only conferences with separate articles are included; within each field, the conferences are listed alphabetically by their short names. General * FCRC – Federated Computing Research ... References {{Authority control ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denali (operating System)
The Denali operating system is "an IA-32 virtual machine monitor, that allows for untrusted services to be run in isolated (protected) domains." Denali makes use of paravirtualization to support high performance virtual machines, even on the notoriously uncooperative x86 architecture (see x86 virtualization). The envisioned usage model for the original Denali was to support virtual machines running lightweight single application operating systems for internet services. A later revision of Denali (uDenali) includes support for running full-featured operating systems. References "Lightweight virtual machines for distributed and networked systems" Developer's page. University of Washington. "Scale and performance in the Denali isolation kernel" Association for Computing Machinery The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the world's largest scientific and educational computing society ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paravirtualization
In computing, paravirtualization or para-virtualization is a virtualization technique that presents a software interface to the virtual machines which is similar, yet not identical, to the underlying hardware–software interface. The intent of the modified interface is to reduce the portion of the guest's execution time spent performing operations which are substantially more difficult to run in a virtual environment compared to a non-virtualized environment. The paravirtualization provides specially defined 'hooks' to allow the guest(s) and host to request and acknowledge these tasks, which would otherwise be executed in the virtual domain (where execution performance is worse). A successful paravirtualized platform may allow the virtual machine monitor (VMM) to be simpler (by relocating execution of critical tasks from the virtual domain to the host domain), and/or reduce the overall performance degradation of machine execution inside the virtual guest. Paravirtualization r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L4 Microkernel Family
L4 is a family of second-generation microkernels, used to implement a variety of types of operating systems (OS), though mostly for Unix-like, ''Portable Operating System Interface'' ( POSIX) compliant types. L4, like its predecessor microkernel L3, was created by German computer scientist Jochen Liedtke as a response to the poor performance of earlier microkernel-based OSes. Liedtke felt that a system designed from the start for high performance, rather than other goals, could produce a microkernel of practical use. His original implementation in hand-coded Intel i386-specific assembly language code in 1993 sparked intense interest in the computer industry. Since its introduction, L4 has been developed to be cross-platform and to improve security, isolation, and robustness. There have been various re-implementations of the original binary L4 kernel application binary interface (ABI) and its successors, including ''L4Ka::Pistachio'' ( Karlsruhe Institute of Technology), '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emulator
In computing, an emulator is hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run software or use peripheral devices designed for the guest system. Emulation refers to the ability of a computer program in an electronic device to emulate (or imitate) another program or device. Many printers, for example, are designed to emulate HP LaserJet printers because so much software is written for HP printers. If a non-HP printer emulates an HP printer, any software written for a real HP printer will also run in the non-HP printer emulation and produce equivalent printing. Since at least the 1990s, many video game enthusiasts and hobbyists have used emulators to play classic arcade games from the 1980s using the games' original 1980s machine code and data, which is interpreted by a current-era system, and to emulate old video game consoles. A hardw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
