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AFAIK, KVM needs HVM.
An Introduction to Full Virtualization With Xen (Linux.com)
Posted Oct 24, 2012 4:53 UTC (Wed) by stefanha (subscriber, #55072)
No, KVM has always done HVM. HVM means using the hardware virtualization extensions (Intel VMX or AMD SVM). This allows unmodified guest operating systems to run.
Speaking of KVM, there is a project called Xenner to run Xen PV guests on KVM. More info here:
[Disclaimer: I work on KVM]
Posted Oct 24, 2012 7:35 UTC (Wed) by drago01 (subscriber, #50715)
Your answer does not make sense, what he said is that KVM needs (as in requires) hardware virtulaization extensions to work, while Xen does not (for paravirualizied guests).
Posted Oct 24, 2012 12:32 UTC (Wed) by cesarb (subscriber, #6266)
Yes, that is what I meant. I did not notice that "needs" could be read in an alternate way (as in "should have" or "is missing"); sorry for the confusion.
The problem is that not all systems are able to do hardware virtualization. You have older machines which are from before the virtualization extensions, newer machines where for some reason the virtualization extensions are disabled by the BIOS, and Intel processors where the same model might or might not have virtualization extensions (unless you know to look at http://ark.intel.com/ before buying).
Posted Oct 24, 2012 14:38 UTC (Wed) by raven667 (subscriber, #5198)
Posted Oct 24, 2012 15:08 UTC (Wed) by gnb (subscriber, #5132)
is a plausible laptop/low-end desktop CPU, 64-bit, came out this year, no VT-x.
Posted Oct 24, 2012 16:38 UTC (Wed) by drag (subscriber, #31333)
Intel intentionally disables features to create market segmentation. AMD does not do this and as such AMD is a superior processor for Linux desktop users that don't want to spend lots of money.
The idea of having the possibility of using Xen-style paravirtualized systems is lovely, but in practice it leaves a lot to be desired.
Two of the biggest reasons for using virtualization are to deal with legacy software that requires a specific configuration and being able to run Windows systems on Linux. Both of those things don't exist for Xen without VT hardware support.
AND if you can take advantage of using Xen PV without changing kernels or anything like that then you will almost always get better performance if you use something like LXC.
Posted Oct 26, 2012 21:47 UTC (Fri) by jond (subscriber, #37669)
Posted Oct 26, 2012 22:16 UTC (Fri) by dlang (✭ supporter ✭, #313)
at one time Xen was "the way to do virtualization" on Linux, and enterprises that setup their networks at that time aren't willing to change.
Actually, I strongly suspect that most of those organizations are still running the OS versions that they installed on the systems, but because of the 'installed base', having Xen updates in new versions is 'important', even for those companies that aren't running the new versions (after all, they may want to, and it shows that they made the right decisions way back when)
Posted Oct 26, 2012 21:46 UTC (Fri) by jond (subscriber, #37669)
Posted Oct 27, 2012 1:25 UTC (Sat) by ixs (subscriber, #47170)
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