Paravirtualization
In computer science , paravirtualization is a virtualization technology that provides a software interface that is similar, but not identical, to the actual hardware. The operating system must be ported in order to be able to run on the virtual machine (VM), which the rights holders of proprietary operating systems can refuse for strategic reasons. Porting, however, simplifies the structure of the VM and enables the virtual machines running on it to perform better.
history
“Paravirtualization” is a new term for an old idea. IBM's z / VM operating system has provided such functionality for several decades. In this operating system, this function is called "DIAGNOSTICS code" because it uses commands that are normally only used by hardware maintenance software. IBM's Conversational Monitor System uses DIAGNOSTIC codes to start services in z / VM. The Parallels Workstation operating system calls the same function “hypercall”. This is always a system call to the underlying hypervisor . Such calls must be supported by the guest operating system, which must provide code adapted to the hypervisor that makes these calls.
Implementations for the x86 architecture
Paravirtualization is usually carried out in ring 0 of the x86 architecture. The operating system is changed in such a way that it can do without any command execution in ring 0.
The term "paravirtualization" was first used in the research literature in connection with the virtual machine of the Denali operating system. The term is also used in the descriptions of the Xen , L4 , and TRANGO hypervisors. These projects use paravirtualization to support powerful virtual machines on the x86 architecture.
swell
- ^ A. Whitaker, M. Shaw, and SD Gribble, "Denali: Lightweight Virtual Machines for Distributed and Networked Applications," Univ. of Washington Technical Report 02-02-01, (2002). (To be found at Denali publications, technical reports, and talks ( Memento of the original from January 14, 2008 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice . )
See also
Web links
- Detailed information on paravirtualization (storage virtualization, server virtualization, operating system virtualization, etc.)