Recently a change in the Linux virtualization landscape has appeared with the introduction of the Kernel virtual Machine. KVM supports the virtualization of Linux guest operating systems – even Windows – with hardware that is virtualization-aware. Learn about the architecture of the Linux KVM as well as why its tight integration with the kernel may change the way you use Linux. Update: An interview with the KVM lead developer.
Although very little approaches the design brilliance of IBM’s early VM work (it’s taken us 40 years to rediscover the power of virtualization-friendly hardware), embedding a virtual machine monitor in a kernel makes too much sense to ignore. It vastly simplifies the VMM design (no need to write a bare OS to boot it and talk natively to hardware), while interfering little with the design of the OS itself. Simple, elegant, beautiful.
I can’t wait to see some solid benchmarks on common VM usage scenarios comparing KVM to Xen, VMWare &co.
Now, if I only had a Core 2 Duo to play with…
to get anything much out of kvm or even xen, you need a vt-capable processor like certain top-end core2duos or opterons.
this is why vmware is going to be king for a while yet, the average desktop doesn’t have the hardware, and unless you’re purchasing hardware *right now* then neither does your existing server.
with that hardware, in theory performance should go kvm->xen->vmware
… hence the final line of my comment…
“you need a vt-capable processor…”
I want one! But I don’t know exactly what to get. I could figure out which processors would run it, and then I see articles which say you need to turn on a switch in the bios; I’ve even seen articles which say the bios has no option to turn it on even though it should support it!
Articles on Xen and KVM start out, “if you can run this command, and get a response, then you can use VT extensions” or something like that.
Well, I don’t want to keep buying CPU’s and motherboards until I get one that works!
Someone — advertise a reasonable priced system. I’d buy four of them:
160 GB high quality drive
At least three PCI slots so I can put in network cards
2 GB RAM (though preferable upgradeable to 4 GB)
No funky hardware
Currently for the client PC market:
Intel: Conroe, Kentsfield, and most Merom CPUs (Core 2 Duo/Quad/Extreme E/Q/X/QX6xxx for socket LGA775, Core 2 Duo T5600+ for mobile socket M)
AMD: Brisbane and Windsor (Athlon 64 X2 for socket AM2)
Edited 2007-04-25 04:07
All AM2 processors from AMD include hardware virtualisation.
All Core2-based processors from Intel include hardware virtualisation.
For more AM2/Core2 stuff, it’s a simple BIOS tweak to enable/disable this hardware. Some motherboards require a BIOS update, and some Intel chipsets that support Core2 don’t support the virtualisation features (but all the AMD AM2 chipsets do).
So, it’s not exactly high-end stuff that’s required.
Actually some Core 2 Duo models don’t support Intel VT. You can find out what products have what features on the appropriate manufacturer websites. The Intel page is found here, just filter in Intel VT products: http://processorfinder.intel.com/List.aspx?ProcFam=2558&sSpec=&OrdC…
Agreed. I played with it for a while on my Turion X2 powered laptop. Certainly not high-end, got it for a steal at one of the big box stores because it was EOL.
Interestingly, Intel permits the virtualization to be disable by BIOS settings on some (or all) Core2’s. HP, among others, doesn’t permit it to be enabled via BIOS on some (or all) of their laptop models. Came across quite a few frustrated posts from owners of shiny new top-dollar Core2’s that were unable to properly play with KVM.
AMD, on the other hand, doesn’t have a mechanism to disable it so the virtualization is available even on some of the lowest end consumer platforms available.
I think the issue is probably needing newish hardware, rather than high-end hardware. Won’t be long til it’s common.
Most Sony Vaio laptops seem to have it disabled too.
According to this page:
http://wiki.xensource.com/xenwiki/HVM_Compatible_Processors
Core 2 Duo E4300 is also not supported.
Where was this article last night when I was recompiling my kernel? I took an educated guess at which modules to compile, especially the one that said KVM but wasn’t sure if other modules had to be installed with it for it to work properly. Then there was the other question of how do I use it? This article gave a good reference, “kvm -no-acpi -m 384 -cdrom guestos.iso -hda vm-disk.img -boot d”. I’m looking forward to actually trying it out tonight.
Don’t worry about it. Releases newer than kvm-12 need a newer version of the kvm module than the one shipped in 2.6.20.*. It’ll build and overwrite the default just fine. In other words, you would rebuild the modules anyways.
So the simple answer for no worries is to buy an AMD AM2 system to know I’ll be able to run KVM. Please correct me if I misunderstood or am missing out on some fantastic Intel functionality.
I do like simple answers. Thanks for the replies!
From what I understand, the AMD virtualization has all the functionality that the Intel stuff has, plus IOMMU support (not actually supported by any software though). So yeah, if you don’t need to have the fastest or most energy-efficient processor, AMD is probably the best choice for playing with virtualization.
Too bad Virtualbox wasn’t brought up in the interview.
I just reformatted my Gentoo box and started from scratch.
I now have Xfce 4.4.1 and Beryl 0.2.1
I want to occupy one of the faces of my 3d beryl cube with a virtualized Windows XP.
As my Pentium 4 doesn’t have the proper extension to run KVM, I am stuck with VMWare Player, Qemu, or Virtualbox.
VMWare Player doesn’t do snapshots and you can’t create images.
Virtualbox seems easier to get running that Qemu.