Talk:Paravirtualization

From Wikipedia, the free encyclopedia

I deleted the use of the term "abstraction" from this page. Reason: (para-)virtualization needs to be distinguished from abstraction. Virtualization does no abstraction at all. This issue is detailed in an IEEE Magazin (think, it is the april 2005 issue or so).

Interface is a better word. Good catch. Mark Williamson 03:29, 17 September 2005 (UTC)

The article combines two related but separate things and calls them both paravirtualization, specifically, that of presenting a differing software interface and that of making a hypercall into the VM layer. Hypercalls are one (common) method of implementing paravirtualization. It's perfectly possible for a hosted OS to use a hypercall for something other than virtualisation support - IBM's VM-CMS uses it for management of virtual machine resources. Lucidion 17:42, 8 January 2007 (UTC)

Regarding this edit... I added back some of the text, because it seemed useful. Even if redundant with the text that replaced it, it's a less technical (more accessible) version.

Also, regarding the "layer 1 of an x86 architecture" statement... is this needed? Paravirtualization seems like it's a concept that could apply to any platform, and even though the examples given are all x86, it would still be nice to keep the article more or less platform-agnostic (unless it's really the case that paravirtualization will never be used on other platforms, in which case, this information should be stated earlier and more prominently). --Interiot 16:38, 26 September 2005 (UTC)

[edit] More details on usage

Could the article have more details on the uses of paravirtualization, like is it used in modern-day x86 systems, and if so, how, where, when and why is it used over standard virtualisation?

Is it a major change to convert an operating system to support paravirtualization? Possibly links in the related section to other alternatives to paravirtualization.

If anyone knows the answers to the above, then I suggest they are intergrated into the article, as I feel it's a bit short on detail at the moment.

Thanks --Wierdy1024 20:07, 5 April 2006 (UTC)

[edit] Ring 0

Actually, Xen on AMD processors runs in "Ring -1", sometimes called "AMD Virtualization Technology". Both Intel and AMD are adding better virtualization support, but in totally incompatible ways. I suggest either dropping the details from the article, or finding an operating system internals expert to write a better description.

Actually, we currently have at least these options for virtualization of x86:

  • Simulate and translate for execution on non-native hardware. Example: Virtual PC
  • Prescan code and patch out non-virtualizable instructions. Example: VMware
  • Write special version of OS that doesn't use non-virtualizable instructions. Example: Xen/Linux.
  • Use new hardware support for virtualization, run unmodified OS. Example: Xen/Windows

Anybody want to take this and go with it?

--John Nagle 02:50, 6 April 2006 (UTC)

Retrieved from "http://en.wikipedia.org../../../p/a/r/Talk%7EParavirtualization_1a49.html"