Archiv verlassen und diese Seite im Standarddesign anzeigen : xen dom0 kernel. What about 2.6.25 and pvops?

04.03.08, 23:23
Sorry for the strange title, didn't find a better one. The questions are:confused: at the end ;-)

I want to start with some general understanding about xen, because I fear that the whole thing is a bit tricky and I might be wrong at some point.

I heard that for xen you need dom0 and domU kernel. The domU kernels are the operating systems which are being virtualized in addition to the dom0 one who also manages these systems. For example if I run linux on dom0 regularly and windows on domU (this is what I want to do) then linux manages the domU system and can be used on its own aswell. There would be no real need to setup a domU linux aswell.
Www.kernel.org supports domU kernels but no dom0 kernels. So with the right compiling options set I can produce domU kernels but there is no way to get a dom0 kernel that way. These dom0 kernels have to be build from xen-linux repositories or the sources. Here comes the problem: They lag behind the kernel.org kernel. The current dom0 kernel is 2.6.18.
Since this is so much lag the xen developers said that they want to improve pv_ops. They plan do put that into the kernel.org kernel at some time. However in the near future this means that 2.6.18 stays the current xen dom0 kernel for a while. (I heard rumors that there are some patches around. But it is not possible to get to 2.6.24 with patches, don't know how far you can get)

In the Fedora project they said that Fedora 9 comes with pv_ops which kills all these dom0 problems and then there will be only one sort of kernel serving both dom0 and domU.
In how far is this related to the Fedora Project? Is it not more connected to a new xen release? Will I be able to use this new stuff with Debain then aswell? What will I have to do then?
Will the 2.6.25 kernel be with dom0 and domU support already?

09.03.08, 17:27
Are you subscribed to fedora-xen mailinglist? This should be a good starting point. (maybe it clears some of your problems)

Fedora's Xen hackers have been working hard towards switching
our kernel-xen package from a forward-ported Xensource kernel tree to a
state-of-the-art upstream, paravirt_ops based, kernel in Fedora 9 as
described here:


Some great progress has been made, and tomorrow's rawhide will
have a kernel-xen update with:

+ A very recent 2.6.25-rc4 base

+ Xen paravirt_ops DomU from upstream

+ x86_64 Xen paravirt_ops DomU support

+ Paravirt framebuffer

However, although the Dom0 paravirt_ops work is well advanced at
this point, we still don't have backend drivers or x86_64 Dom0 working.

With the feature freeze looming next week, we have make the
difficult decision to focus the Fedora 9 efforts on DomU and postpone
the inclusion of paravirt_ops Dom0 support.

The alternative course of action was to keep shipping the based kernel-xen in Fedora 9, but we have ruled this out as a
supportable option. This kernel is almost a year old now and we cannot
expect Fedora hackers to keep the distribution working on such an old
kernel. Examples of the kind of issues we see cropping up are:

1) Broken installs due to old squashfs:


2) Broken SELinux due to old SELinux:


3) Broken networking due to old netlink:


We feel that making significant investment across the
distribution to keep this old kernel working for the sake of Dom0
support would be wasting effort on a dead codebase.

Work will continue apace on the Dom0 paravirt_ops effort for
Fedora 10 and we hope to introduce the first build to rawhide soon after
Fedora 9 been branched. This first build should include backend drivers
and x86_64 support. If all goes well with the Dom0 support in Fedora 10
rawhide, we may well pull it into Fedora 9 as a post-GA update.

So, in summary:

1) Try out the F9 rawhide/beta paravirt_ops kernel-xen in your DomUs

2) Keep your Dom0 on Fedora 8 for now

3) If you want to help out with Dom0 paravirt_ops testing, then be
ready to jump onto Fedora 10 rawhide

Greetz 403

09.03.08, 17:44
nein, aber ich habe jezt die xen-devel liste aboniert *g*

dank dir :)

09.03.08, 17:49
hihi, alles klar :)