WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

RE: [Xen-users] help unmodified OS compatibility

To: "Jesús Velazquez" <jesus.velazquez@xxxxxxxxx>, xen-users@xxxxxxxxxxxxxxxxxxx
Subject: RE: [Xen-users] help unmodified OS compatibility
From: "Petersson, Mats" <Mats.Petersson@xxxxxxx>
Date: Wed, 22 Feb 2006 22:42:31 +0100
Delivery-date: Wed, 22 Feb 2006 21:43:36 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcY39H9NUKSMq/xoRIKwdQ65MDS/MgAAWZYQ
Thread-topic: [Xen-users] help unmodified OS compatibility
> -----Original Message-----
> From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx 
> [mailto:xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of 
> Jesús Velazquez
> Sent: 22 February 2006 21:04
> To: xen-users@xxxxxxxxxxxxxxxxxxx
> Subject: [Xen-users] help unmodified OS compatibility
> 
> Hi, I have a question regarding the current unmodified OS 
> compatibility using Intel VT technology.
> 
> Which are the current unmodified OS supported by Xen 3.0.1?
> 
> I have trying to install several OS, among them are Solaris 
> 10, FreeBSD 6.0, Windows 2000 Server, Windows NT 4, Suse 
> Linux 10, Suse Linux Enterprise Server 9 and none of those 
> are enable to boot install, install or boot.
> 
> The running unmodified guests using VT are RedHat Enterprise 
> Linux 4, Fedora core 4, Windows Xp and Windows 2003 
> Professional and the Server version.

That's probably a pretty close approximation of what has been seriously tested 
so far. The difficulty is that each OS has it's own little quirks about how 
they do certain things - for example, Windows executes several instructions 
AFTER it's set bit 0 in CR0, without performing a jump to the protected mode 
code-segment, so the code looks like it's running in protected mode in CR0, but 
CS is still using the old "real-mode" values. This is not how the documentation 
SAYS you should do things, but it works... 

So, until someone decides to actually figure out WHY the different OS's don't 
work, and fix whatever needs fixing, they will continue to not work... 
Depending on various different factors, this may happen sooner or later - one 
of those factors is of course participation and bug reporting, another is 
vendor presssure, and user pressure. At the moment, I'd say that unmodified 
OS's are still in it's infancy, and if something works, great. If it doesn't, 
supply a bug-report [obviously check first if there is someone else that 
already complained about the same thing - we probably don't need to know more 
than once if WinNT4 doesn't work], but don't expect it to be changed 
immediately... ;-) We're still struggling to get the basics working well... See 
more below. 

> 
> Anyone have an official supported unmodified OS using VT technology?

Try looking at Xen-devel-list, and there will be a test-report issued about 
daily from various people listing what tests they have run. This will indicate 
how a particular OS is doing - of course, if what you want to run isn't listed, 
it probably means that it's not on the priority list. For quite some time, 
Intel's testing showed that they couldn't boot WinXP at all - not saying they 
weren't trying hard to fix it, and we've (AMD) certainly had situations where 
we've struggled to figure out what's broken and/or find the right fix for 
something not working. Running unmodified guests is not an easy task - you need 
to understand quite a lot about what the guest is trying to do when something 
goes wrong - and the programmers that work on various OS kernels are often very 
clever people, that can figure out how to do things in many different ways - 
not all of which are obvious. Not having the source code in many cases doesn't 
help much... 

> When is going to be release Xen 3.0.2 ?

Not sure if there's been any announcement. Ian said something at Xen summit 
about 6-8 weeks between dot-releases, but I'm not sure if this is a target or 
an absolute [and it's obviously no point in releaseing a dot-release if there's 
no valuable changes]. 

> What about the ACPI support for unmodified Guests?

There is an ACPI region supplied in the guest E820 table, but I'm not sure what 
information you're asking for and whether it's in this table or not - ACPI 
contains a lot of different "things", and some may be simpler than others to 
emulate. 

And of course, just because there's an entry in the E820 doesn't mean that it's 
containing useful stuff... In my system, "dmesg" shows a message saying "ACPI: 
Unable to locate RSDP", which is, it appears the "Root System Descriptor 
Table", and this would probably be fatal for the ACPI... So I guess there's 
more work to be done here... Do you volunteer?

> Where can I find this kind of information?

This mailing list, as well as Xen-devel will have some information - I don't 
think there's a single location that contains all of what you want, 
unfortunately. Obviously, I'll be ever so happy if someone told me that I'm 
wrong in this case... 

--
Mats
> 
> 
> Thanks.
> 
> Jesus
> 
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users
> 
> 


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

<Prev in Thread] Current Thread [Next in Thread>