The first stable Xen release
| From: | Ian Pratt <Ian.Pratt@cl.cam.ac.uk> | |
| To: | linux-kernel@vger.kernel.org | |
| Subject: | [ANNOUNCE] Xen high-performance x86 virtualization | |
| Date: | Thu, 02 Oct 2003 10:17:18 +0100 | |
| Cc: | xen-devel@lists.sourceforge.net |
We are pleased to announce the first stable release of the Xen virtual machine monitor for x86, and port of Linux 2.4.22 as a guest OS.
Xen lets you run multiple operating system images at the same time on the same PC hardware, with unprecedented levels of performance and resource isolation. Even under the most demanding workloads the performance overhead is just a few percent: considerably less than alternatives such as VMware Workstation and User Mode Linux. This makes Xen ideal for use in providing secure virtual hosting, or even just for running multiple OSes on a desktop machine.
Xen requires guest operating systems to be ported to run over it. Crucially, only the kernel needs to be ported, and all user-level application binaries and libraries can run unmodified. We have a fully functional port of Linux 2.4.22 running over Xen, and regularly use it for running demanding applications like Apache, PostgreSQL and Mozilla. Any Linux distribution should run unmodified over the ported kernel. With assistance from Microsoft Research, we have a port of Windows XP to Xen nearly complete, and are planning a FreeBSD 4.8 port in the near future.
Xen is brought to you by the University of Cambridge Computer Laboratory Systems Research Group. Visit the project homepage to find out more, and download the project source code or the XenDemoCD, a bootable `live iso' image that enables you to play with Xen/Linux 2.4 without needing to install it on your hard drive. The CD also contains full source code, build tools, and benchmarks. Our SOSP paper gives an overview of the design of Xen, and evaluates the performance against other virtualization techniques.
Work on Xen is supported by UK EPSRC grant GR/S01894, Intel Research Cambridge, and Microsoft Research Cambridge via an Embedded XP IFP award.
Home page : http://www.cl.cam.ac.uk/netos/xen
SOSP paper : http://www.cl.cam.ac.uk/netos/papers/2003-xensosp.pdf
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Posted Oct 2, 2003 13:54 UTC (Thu)
by pspinler (subscriber, #2922)
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I, at least, own VMWare in order to run Windows apps on my linux box. Obviously, MS is unlikely to ever port any version of windows to Xen. -- Pat
Posted Oct 2, 2003 14:12 UTC (Thu)
by jmitchel (guest, #11611)
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Posted Oct 2, 2003 15:05 UTC (Thu)
by eru (subscriber, #2753)
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Posted Oct 2, 2003 21:38 UTC (Thu)
by brouhaha (subscriber, #1698)
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But I've long hoped that AMD would see this as an opportunity, and add support for virtualization to their processors. The main thing that is needed is to add a new mode bit in a control register that, when set, would make a few more instructions trap if not executed in ring 0. A few other issues would also have to be addressed, but I doubt that implementing virtualization would add more than 10K transistors to the processor. This would not result in any noticable increase in manufacturing cost.
If this were done, it would still be necessary to have a hypervisor, but it could be simpler and more efficient than Xen, yet support any guest operating system with no modification.
Posted Oct 3, 2003 4:02 UTC (Fri)
by NZheretic (guest, #409)
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As I have stated before about Microsoft's purchase of Connectix's Virtual Server technology Microsoft needs a Virtual Server for backward compatibility for it's NGSCB ( Next Generation Secure Computing Base ) DRM ( Denial of Rights Mechanism ) platform. Just as Microsoft's XP backward Win9x compatability opens up many locally exploitable API to gain SystemLocal privilege access, to the point where many programs need Adminstrator privilege to run, existing XP and win2k software would open up too many opportunities for helpfull hacker to bypass Microsoft's NGSCB DRM mechanisms. Microsoft's all too obvious solution is to provide a "Virtual" PC mode, running a modified XP and WinME, with the NGSCB providing virtual filesystems and hardware access. All, access of course, with the NGSCB DRM scanning and control. Where do you want to go tomorrow?
Posted Oct 3, 2003 7:39 UTC (Fri)
by edmundo (guest, #616)
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I would guess that Microsoft is interested because Windows is not a truly multi-user operating system and because increasingly Windows has to share its hardware with Linux if it is to be used at all on servers. I would guess that Intel is interested because it lets people have virtual machines without changing to an architecture that provides better support for them. However, I'm not saying you shouldn't worry about DRM, etc.
Given this statement: "Xen requires guest operating systems to be ported to run over it", it appears that Xen is more a competitor to UML than to VMWare.The first stable Xen release
However, the Xen developer had the MS academic source license and has aparently made great strides toward porting XP. Whether this will ever be distro'd beyond the Academic Source License people is a good question, but much of the tech work is done.The first stable Xen release
Actually this sounds more like the "New" Plex86 project
(http://plex86.sourceforge.net/).
than UML. UML isn't really a virtual machine system, but Linux running as an user process (or rather, set of processes).
The first stable Xen release
Intel has never been interested in updating the x86 architecture to support the Popek & Goldberg virtualization criteria, which is why VMware is fairly inefficient for some workloads. (I use VMware and am happy with it; frankly I'm amazed at how efficient it does manage to be.)
The first stable Xen release
A quick glance over the Xen group's paper leaves me very impressed with the performance these techniques can achieve. That the Xen group has decided to release the code under the GPL leaves me very grateful. However, that both Intel Research and Microsoft Research has funded it, leaves me somewhat concerned.Why funded by Microsoft+Intel? NGSCB backward compatibility!
In my opinion Microsoft's acquisition of Connectix's Virtual Server technology has very little to do with running any other vendors operating system.
The Electronic Frontier Foundation have just published an article Trusted Computing: Promise and Risk on the risks surrounding remote attestation model of TCB and NGSCB.
> However, that both Intel Research and Microsoft Research has funded it,Why funded by Microsoft+Intel? NGSCB backward compatibility!
> leaves me somewhat concerned.