Talk:Kernel-based Virtual Machine

Politics behind kvm inclusion decision?

I've seen some articles mention that Xen wanted to be included in the kernel for years, and instead a fairly new component, KVM, gets included.

I was wondering what the background/politics that lead to decision are? It might be an interesting addition to this article.

I'm thinking it's because Xen made a deal with Microsoft - certainly, that seems to be what the latest Linux Format magazine is implying... —The preceding unsigned comment was added by 83.104.34.212 (talk) 14:53, 17 February 2007 (UTC).

It's simpler --Treekids 19:04, 21 August 2007 (UTC)

Needed info

I would like to see a Plain English introduction that explains in layman's terms what KVM means - so far this article starts out loaded with acronyms and terms that are obscure to the moderately educated computer user. Thanks, Walt Bankes

• What OS can run under the VM?
• What's the license on the code? GPL or other?

I couldn't access the project homepage or else I would have looked it up myself. - Taxman ^Talk 18:17, 31 January 2007 (UTC)

Pretty much any OS- KVM provides the guest OS with a fairly vanilla PC (via QEMU's I/O module) that pretty much any PC OS can run on:

i440FX host PCI bridge, PIIX3 PCI to ISA bridge, Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA extensions, PS/2 mouse and keyboard, 2 PCI IDE interfaces with hard disk and CD-ROM support, (opt) Floppy disk, zero or more NE2000 PCI network adapters, Serial ports, (opt) Creative SoundBlaster 16 sound card, (opt) ENSONIQ AudioPCI ES1370 sound card, (opt) Adlib(OPL2), (opt) Yamaha YM3812 compatible chip, PCI UHCI USB controller and a virtual USB hub, one or more CPUs, with SMP up to 255 CPUs. --Treekids 14:36, 4 September 2007 (UTC)

As far as I can tell KVM is just a virtual box app. The word 'hypervisor' should not be used here, as it is a term from Xen; 'host' is more appropriate. A VTx CPU is required. — Preceding unsigned comment added by 220.240.250.7 (talk) 02:20, 28 June 2016 (UTC)

What would be "a virtual box app"? — Dsimic (talk | contribs) 12:00, 28 June 2016 (UTC)

Update

I've updated the page considerably to reflect the progress currently made. Feedback would be useful here. Provided that there are no objections to the current content, I'd like to extend it more in the near future.--Anthony Liguori 00:51, 7 May 2007 (UTC)

Yes, this page needs lot of updating, it is severely lacking in detail; check how detailed [[Xen] is written. Raghu Udiyar (talk) 13:49, 16 November 2011 (UTC)

Usenet references

This page makes extensive references to usenet posts, via the Gmane site. Why that one, instead of the more common (and possible longerlived) google groups archive or a honest-to-god standardised news:// link (which last, admittedly, will be problematic to retrieve for many people)? —Preceding unsigned comment added by 80.101.113.45 (talk) 22:16, 14 September 2008 (UTC)

Gmane is website that archives public mailing lists and provides a mail-to-NNTP gateway. Messages found on Gmane are not present on other Usenet newsservers. -- intgr [talk] 09:17, 15 September 2008 (UTC)

Version numbers and infoboxes

• Recently an IP user made an edit, creating a separate infobox for "kvm-kmod".
• I reverted this stating: "revert, kvm-kmod and qemu-kvm are just Fedora packages, "kmod" is the repackaging of parts of the Linux kernel"
• IP changed it back with message: "user doesn't know what he's talking about, see kvm's download page"

Yes I saw the download page. It explicitly states "The kernel modules can be found in kvm-kmod-<kernel version>. A kernel version of 2.6.32.3 means that these are the same modules as those included with the 2.6.32.3 kernel from www.kernel.org". In other words, kvm-kmod packages KVM kernel modules that are otherwise part of official kernel.org kernels.

And in fact the "kvm-kmod" package is Fedora-specific, other distros like Ubuntu, openSUSE and Arch Linux package these modules as part of the kernel package (look for files kvm.ko, kvm-amd.ko, kvm-intel.ko). The linux-kvm.org website is actually maintained by Red Hat so it's no surprise that they only cover Fedora there.

The problem with the infobox in the first place is that KVM is not one specific piece of software. "KVM" itself is actually a subsystem of the Linux kernel, which provides an user-space API to processor-specific virtualization technologies (VT-x and AMD-V). And then there's QEMU, which was forked into a "QEMU-KVM" project to add KVM support. QEMU-KVM is not KVM either, it's a piece of software that happens to use kernel's KVM functionality. Personally I'd just remove the version numbers from the infobox entirely because the way it's represented now is simply incorrect... But I'm not sure it will stay that way -- surely always there's someone who will add them back.

So, agree/disagree? Ideas? Alternatives? -- intgr [talk] 16:29, 4 May 2010 (UTC)

---

There is nothing Fedora specific about kvm-kmod, it is one of the upstream release packages (along with qemu-kvm).

See http://www.linux-kvm.org/page/Getting_the_kvm_kernel_modules.

Dropping the version numbers is technically correct but would leave the false impression that there is no released software that can use kvm.

Your IP user 77.126.59.18 (talk) 20:06, 6 May 2010 (UTC)

kvm-kmod is Fedora-specific. Name one other distribution that ships KVM separately from the kernel?

As explained above, the linux-kvm.org website is not even the "upstream", it's a Red Hat-owned page that doesn't lead the project or even host any development resources (bug trackers, code, mailing lists etc). kernel.org is the upstream, and they don't release kvm-kmod.

As for leavig the impression of unreleased software, the article could simply state that it's part of the kernel. Do you think that for instance the ext4 page leaves the impression that it's unreleased? -- intgr [talk] 01:04, 7 May 2010 (UTC)

unload intro

Can the following "using the VirtIO framework; this includes a paravirtual Ethernet card, a disk I/O controller, a balloon device for adjusting guest memory-usage, and VGA graphics interface using VMware drivers" be moved out of the intro, to the relevant section on technical details, please ? Thanks in advance. --Jerome Potts (talk) 05:19, 6 August 2010 (UTC)

Is this generic?

It seems that Red Hat was the first to implement KVM, but does that make it proprietary? The way the article was written implies that it is simply a framework, and any kernel can be used to mimic a machine in virtual space.Rajpaj (talk) 06:45, 20 April 2011 (UTC)

KVM was written by Qumranet, before Red hat acquired it. Because it is free software, part of the Linux kernel, any company, not just Red hat can use it or modify it - so it is by no means proprietary. Red hat does have on its payroll all the influential KVM developers, so it has significant leverage on the direction that its development is taking, but nothing is preventing other companies from chipping in. In fact, yesterday, an alliance was formed by several companies (Redhat, IBM, HP, Intel, and others) that want to develop and promote KVM - see [1] Nyh (talk) 14:11, 18 May 2011 (UTC)

Is information needed regarding the original author (inventor) of KVM in this article? Is that the question? Otherwise, bore others with your general questions. Does it need to be said that KVM is an open software solution for the linux kernel, another open software solution and is necessarily not proprietary (i.e. fascist, captialist, intellectual property trash)? Just ask the Free Software Foundation if they'll legally defend that statement, or read up on it, like in wikipedia.Kckid (talk) 22:29, 23 December 2013 (UTC)

Disambiguation

I propose a disambiguation page for this article. My main reason for such a request is that KVM is in reality, a generic forecast. This article specifies only the Linux version.Rajpaj (talk) 23:43, 23 April 2011 (UTC)

Does not depend on VT-X?

The KVM site says that you need hardware virtualization, but the first paragraph of this article suggests that you don't. Which is right? 219.90.148.160 (talk) 11:58, 19 July 2011 (UTC)

If the official developers says something it's bound to be more accurate than a boiled down rehash of comments by the same people. The KVM site is right. — Preceding unsigned comment added by 80.162.60.16 (talk) 22:49, 17 October 2011 (UTC)

How, is that an answer? This article doesn't make it clear. I'm going to edit.Kckid (talk) 21:30, 23 December 2013 (UTC)

It is a clear answer: Follow the sources. It's not appropriate for WP to contradict the published requirements.  — SMcCandlish ☺ ☏ ¢ ≽^ʌⱷ҅_ᴥⱷ^ʌ≼  12:15, 15 June 2016 (UTC)

It's saying that KVM requires hardware virtualization, not hardware emulation. Luke1337 (talk) 01:01, 10 November 2020 (UTC)

"offering additional visibility and storage reliability not previously available"

This sounds more like advertising than anything else. In fact the page seems to have been done-over by a Solaris/BSD flag-waver, what with two backwater OpenSolaris forks appearing at the top of the "implementations" list. Ris icle (talk) 14:47, 22 June 2012 (UTC)

I would agree. But, if one starts looking for this kind of thing especially, in articles connected to the software industry and business automation, it would become a life's work. Not, that I'm discouraging anyone.Kckid (talk) 21:27, 23 December 2013 (UTC)

Cleanup has to start somewhere. We have similar problems like this at Ubuntu (operating system), with flag-wavers sporadically opposing cleanup of the article. (It does not get into the fact that it's primarily a desktop OS, not a server one, aside from the Ubuntu Server variant; the current version's own documentation even says that much of it is outdated, and if you've ever tried to use Ubuntu as an enterprise server you'll very rapidly find out that most of the server-related docs are in fact years out of date. Other problems include citing non-independent, self-published and/or user-generated material right and left, including for potentially controversial claims. I've addressed these problems at its talk page). The overall problem of failure of our tech articles to abide by WP:NOT#ADVOCACY and WP:NPOV policies is widespread, and working to improve this should be done where it's needed.  — SMcCandlish ☺ ☏ ¢ ≽^ʌⱷ҅_ᴥⱷ^ʌ≼  12:20, 15 June 2016 (UTC)

expert-subject: why?

There's been an "expert-subject" ({{Expert-subject|computing|date=October 2012}}) template on this page since 2012, yet it doesn't seem clear to me why. So I removed the template transclusion. --TheAnarcat (talk) 23:27, 5 January 2015 (UTC)

Hello! Yeah, the article is good from the point of having no factual errors. However, it's far away from providing a good coverage of the KVM. :) — Dsimic (talk | contribs) 03:45, 6 January 2015 (UTC)

That may be the case, but it doesn't require an expert to do that; anyone with a *n*x and virtualization background could do the source research necessary. The expert needed tag is for when an article seems to have been hopelessly muddled by non-expert editors who are misinterpreting the source material.  — SMcCandlish ☺ ☏ ¢ ≽^ʌⱷ҅_ᴥⱷ^ʌ≼  12:14, 15 June 2016 (UTC)

Article title capitalization

Hello, SMcCandlish! Regarding your recent renaming of the article to Kernel-based virtual machine, see, KVM actually is a proper name, because it's a specific software product (just like VMware, for example), not some kind of a virtualization concept. Thus, we should rename the article back to Kernel-based Virtual Machine. — Dsimic (talk | contribs) 09:22, 13 June 2016 (UTC)

Sorry; my edit summary was not precisely enough. Whether it's a proper name or not isn't really relevant; a large number of computer science proper names are not capitalized (consistently, or at all) like typical proper names, and are all-lowercase, camelCase or StudlyCaps, among other options. This one in particular is not always capitalized in sources, but does seem to be capitalized in most of them. I'll have WP:RMTR reverse the move.  — SMcCandlish ☺ ☏ ¢ ≽^ʌⱷ҅_ᴥⱷ^ʌ≼  11:10, 14 June 2016 (UTC)

Done.  — SMcCandlish ☺ ☏ ¢ ≽^ʌⱷ҅_ᴥⱷ^ʌ≼  12:09, 15 June 2016 (UTC)

Thank you! — Dsimic (talk | contribs) 10:56, 17 June 2016 (UTC)

Stable release

Mentioning 1.2.0 and 2012 as latest release seems quite misleading, perhaps we should just remove that information? That's only about the old (separate) downloads, as far as I can understand: http://www.linux-kvm.org/page/Downloads Nemo 07:59, 10 February 2017 (UTC)

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VirtIO

VirtIO redirect to this article. There should be a section about VirtIO. Takers? 109.192.123.125 (talk) 13:47, 6 October 2017 (UTC)

VirtIO no longer redirects to this article, but to QEMU, which is a more appropriate place for it. KVM is not actually involved in presenting a device model to guests. There should probably be a dedicated page for VirtIO, since it's not specific to QEMU either, but we can leave that for another time. Nmeyerhans (talk) 05:05, 11 March 2021 (UTC)

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Confusion between QEMU and KVM

A lot of information in this article seems to be concerned with QEMU rather than KVM. Sections "graphical management tools" and "emulated hardware" are especially irrelevant to KVM and most of their contents apply to QEMU (or qemu-kvm). Section "emulated hardware" also contradicts with the prior statement that KVM does not perform emulation. Magic sergeant (talk) 03:40, 21 November 2018 (UTC)

I deleted most of the hardware emulation content here and updated the text to indicate that device emulation is provided by the userspace application. There are several available, each of which presents a different device model. KVM itself emulates very few devices. Nmeyerhans (talk) 16:53, 11 March 2021 (UTC)

Clarification of the emulation confusion

I’ve tried to clarify the confusion about emulation mention in the note in the “Emulated Hardware” section. Please check if it is clear now and change or remove the note — Preceding unsigned comment added by Rafimoor (talk • contribs) 04:18, 31 August 2019 (UTC) Rafimoor (talk) 04:20, 31 August 2019 (UTC)

Layman inconsistencies in the artle

I'm not an expert but these two statements seem to entirely contradict each other.

"KVM provides device abstraction but no processor emulation."

and:

"KVM itself emulates very little hardware, instead deferring to a higher level client application such as QEMU, crosvm, or Firecracker for device emulation. KVM provides the following emulated devices: Virtual CPU and memory VirtIO"

This needs to be clarified because it makes no sense. 2601:646:9E01:B460:2D40:3293:BD31:BF66 (talk) 19:22, 7 July 2024 (UTC)