Mac OS X and Xen Optimizer? Is this relationship the future of Windows on the Mac?
=======Mac OS X and Xen Optimizer? Is this relationship the future of Windows on the Mac?
>>>>>>> .r7754I had a really interesting conversation with a guy from founder of XenSource, Moshe Bar last weekend. He sent me an instant message and since these guys will may at some point be able to provide an alternative to dual booting the Intel Mac, I was interested to learn some more.
What I found out from him was pretty interesting stuff. For those of you that are unfamiliar with Xen and what it does, I will try to explain in a very high level way (which is the extent of my understanding). Xen loads right after the computer boots up, and loads into memory. Xen sits as an interface between the operating system and the hardware. This gives Xen the ability to allocate resources when running multiple operating systems; i.e. virtualization. You are able to run more than one OS, not running one on top of another, but side by side, simultaneously.
I bet some of you are thinking: What is the cost to my resources to run Xen? Xen costs you approximately 1% of your system resources to run it. Not too bad.
At the moment, the Xen guy told me that using Xen, he is able to run Windows XP Linux and Freebsd on the Intel Mac, (his iMac) but not Mac OS X. What??? Well, that’s what he said. I would really like to see that. The time frame for Mac OS X running on Xen is likely 4Q ‘06. This, however, is his pet project and not an official XenSource project.
The other interesting thing we talked about is how Mac OS X currently interfaces with the hardware. I am really unfamiliar with much more than the buzzwords, so I will do my best to explain. Currently, Apple uses the Mach Kernel to interface with the hardware. However, “Mach” is essentially outdated and causes a lot of the bottlenecks with programs having to create a lot more processes than necessary to get the job done. The guy from Xen told me they have been talking a great deal with the Apple guys about replacing Mach with Xen. This is a really big deal! This would be consistent with reports that Apple has filed patents related to Virtualization.
The reason Apple has not switched OS X to use Xen instead of Mach yet according to the guy at Xen Moshe is because XenSource has not yet implemented the system to support the intensive graphics requirements of Mac OS X.
My prediction is that in OS X 10.6, we will see some sort of fast-user switching between operating systems. Is that realistic, or am I just dreaming?
EDIT: I have corrected this - apparrently he has not been able to run Windows yet since he says this requires Intel’s VT CPUs.
Update: I referred a reporter from Computer World to Moshe Bar, the guy with whom I spoke. In this article, Moshe clarifies some of the things I was confused on. I got a few very key details wrong.
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February 1st, 2006 at 12:13 am
At the moment, the Xen guy told me that using Xen, he is able to run Windows XP and Freebsd on the Intel Mac, but not Mac OS X. What??? Well, that’s what he said. I would really like to see that. The time frame for Mac OS X running on Xen is 4Q ‘06.
Is that the result of playing around on the DTK machines, or have they actually attempted that on the production machines that Apple is now shipping? Any way to clarify that?
-Ralf
February 1st, 2006 at 12:18 pm
According to the guy, it was a new Intel iMac, not the dev machine.
February 2nd, 2006 at 2:55 pm
I’d like to see that too. Did this person say how they did it? Would we would be able to duplicate?
February 2nd, 2006 at 3:01 pm
I think that he is using a development version of Xen that he is working on - I dont think you can go out and download it.
February 3rd, 2006 at 7:49 am
dream on!
lm
February 4th, 2006 at 7:38 am
Let’s think reverse, how about other PC makers,Dell,HP,Gateway,make new PC’s with Intel DualCore and find the way what we are waiting for?
February 4th, 2006 at 7:27 pm
I do not see this happening. Apple must know that Macs easily dual booting into Windows is probably not a good thing. If Macs could, I suspect many developers like Adobe could no longer jusitify the expense of making software for Macs. Why would they if Macs could easily boot Windows and run the programs? It is not like their users are going to abandon them, easpecially if people are already dual booting into Windows to run Windows only applications. Developers will justifiably be tempted to cut their deevelopment cost by going Windows only.
Moreover, I doubt Microsoft wants Macs dual booting into Windows easily. Allowing this could be risky because although it is unlikely, it is possible that many long time Windows users would stop booting into Windows all together.
For what it is worth, I hope people do not solve this problem anytime soon, as I love my Mac and do not want to be forced to boot into Windows to run applications I have grown to love on the Mac.
February 4th, 2006 at 10:47 pm
Im much more interested in this type of windows use, instead of dual booting, according to “independent” test results, xen is much faster than vmware, well have to see how it compares to vpc, iemulator etc.
That said, the ability to dual boot would be enticing from a consumer perspective.
February 5th, 2006 at 2:08 pm
Um… Microsoft licensing issues prevent the Xen-compatible version of Windows XP/Xen-implementation under Windows XP from being released to the public. Is this not a large problem?
February 6th, 2006 at 8:35 am
Since Xen is opensource, the build that this guy is using should, theoretically, be available. That being the case, it should be a simple matter to partition a hard-drive, install Xen+XP on one partition, OS X on the other and have a dual-booting system today. Seems to me, this guy could claim the $10k tomorrow if he wanted to.
February 6th, 2006 at 10:06 pm
I just emailed Xen about this. Here is their reply:
Stephen
I read the blog, and it’s wildly inaccurate. Here are some facts - feel
free to put them on the blog as followup if you’d like:
1. Yes, one could run theoretically Win/Tiger on Xen, on a new Intel Mac
however I personally have yet to see Xen run on the new Macs.
2. XenSource is not working on this as a product right now, but someone in
the Xen community may be.
Regards
Simon
February 7th, 2006 at 7:48 pm
Another email… Note he says Q3 06.
Yes, in theory Xen could do all of this. Indeed Xen can even virtualize the
TPM to enable MacOS to securely boot, and support Vista licensing and TCB.
We will have a Windows on x86 product in Q306. It may just solve this
problem, but I’m not sure. Let me think this through for a bit and get back
to you.
We’re talking to Apple, that’s all I can say right now.
February 11th, 2006 at 6:52 pm
Actually, the new Intel iMacs have Intel’s VT built-in. All Intel Core Duo processors do (The Register and other sites reported that it didn’t. They’re wrong. Take it from someone who has a Core Duo T2400 noteboook sitting in front of them, that’s reporting it supports VMX instruction set ;)).
March 7th, 2006 at 12:58 pm
If you lay out OS X in a block diagram, you’ll see that Mach and Xen are completely different layers. Saying the Mach Kernel is an interface to hardware is like saying the engine in a car turns the tires.
At one time Mach research was heavily funded by much of the computer industry and DARPA. These days, it’s pretty much just Apple and even they only use a remnant of what was originally produced.
The Mach interfaces have always been slow and I vaguely remember seeing some OS X context switch tests that highlight the problem. It’s hard to see what benefit it provides.
Xen is no more a combination of holy grail, mouth wash and floor wax than Mach was. When these kinds of ridiculous claims are made people should realize that similar claims were made about Mach (and others).
BTW, a TPM should not be virtualizable - it defeats one of the underlying premises (that ever component running on the is registered as it runs). It IS possible for a Virtual environment to be trusted and in turn provide access to the TPM but the notion that a virtualizer can be interposed without detection violates the model. Any claims to the contrary should be highly suspect. Would you buy a product from from someone making that claim?
March 14th, 2006 at 4:13 pm
I am not sure whether OS X license allows running the OS as a guest.
Did anyone ever contact Apple for clarification? Is there a precedent?
Running Xen with Linux as a ring 0 OS should be simple enough, as it should theoretically be equivalent to booting Linux on MacTel.
Running [patched ?] OS X under VM has been done according to plenty of folks, but that’s not legal therefore not a practical long term approach…
In a few months there will be plenty of Workstation products for MacTel hosts, so what’s the big deal?
March 24th, 2006 at 3:33 pm
The TPM is virtualizable. A very thin domain multiplexes it, that domain is itself attested in the secure boot.
http://www.xensource.com/files/xs0106_intel_xen_security.pdf
technotes says: “the notion that a virtualizer can be interposed without detection violates the model”
It’s not done “without detection,” it just inserts a layer in the attestation process.
October 5th, 2006 at 10:19 am
You wrote:
>
Mach is actually a pretty modern kernel, and as far as resources go, offers better utilization than some others. It is a microkernel deisng, and it uses more modern message passing techniques, which allow better communication between processes - this is built into the os, when you use the mach kernel…
Also, Mach was the kernel chosen for the Next machine, which is of course where OS X came from - I think we forget that frequently.
To see where you are, you need to know where you came from.
November 13th, 2006 at 5:29 pm
Guys, just read http://www.scl.ameslab.gov/Projects/mini-xen/index.html
and you can see Xen working on Mac-mini, but no MacOS X yet, though