Xen Not Displayed in Boot Menu
by sorabh hamirwasia
Hi,
I have installed "Xen" on Fedora16 host using "yum install xen" command and
it has been installed properly. I can see the changes in /etc/grub2.cfg
file too. But when I reboot then the entry for Xen is not listed in the
boot menu. On further analyzing I found that in /etc/grub.conf there is no
entry related to Xen. Do we need to modify grub.conf manually ? If yes then
how to do that. ?
Please help me with this.
--
Regards,
Sorabh
11 years, 3 months
Xen/Linux 3.4.2 performance
by W. Michael Petullo
We have seen a significant reduction in performance in our research DomU
OS kernel when running on Fedora 16 with Linux 3.4.2 vs. 3.3.7. We run
a series of benchmarks which are DomU-kernel-space-CPU-heavy; many of
these run 10x slower when using the 3.4.2 Linux kernel as Dom0.
This is a little surprising---we've been tracking the Fedora kernels for
a long time with no problem like this. Did anyone else notice any changes?
--
Mike
:wq
11 years, 4 months
Re: [Fedora-xen] Xen Test Day
by Dario Faggioli
On Thu, 2012-07-26 at 09:23 -0400, Konrad Rzeszutek Wilk wrote:
> Would it make sense to conjoin it with the amazon ec2 day?
>
It sounds like it could make sense, the only problem being (sorry) I'm
not sure I know or can find out what the "amazon ec2 day" is or is
supposed to be... :-)
Did you mean something like proposing an EC2 TestDay?
Thanks and Regards,
Dario
--
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://retis.sssup.it/people/faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)
11 years, 4 months
Xen Test Day
by Dario Faggioli
Hi guys,
I was thinking about submitting a request for a Xen TestDay (see here:
https://fedoraproject.org/wiki/QA/Fedora_18_test_days).
What do you think? There is already a Virtualization
(https://fedoraproject.org/wiki/Virtualization) TestDay scheduled
(https://fedorahosted.org/fedora-qa/ticket/303), but I think it would
make sense to have a Xen specific event.
I'm out figuring out the details right now, in the meantime, what date
would you think it would work best? I was thinking about 2012-10-11
(right the week after the virtualization one).
Let me know your thoughts ASAP, as I was thinking to submit the
qa-request by today or tomorrow, before we run over of slots! :-)
Thanks and Regards,
Dario
--
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://retis.sssup.it/people/faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)
11 years, 4 months
Xen, Fedora, and UEFI Secure Boot
by M A Young
I contacted the people behind the the Fedora Seure Boot feature and got
the following responses, from Peter Jones:
Okay, to be honest I don't remember much about Xen's layout - dom0 is the
management kernel the hypervisor starts? So, depending on how xen works,
there
are probably more things that need to be done in the hypervisor than in
the
kernel, because the hypervisor is the part that does most physical memory
accesses, and that's where there's a worry about faking SB=0 and launching
windows.
At the very least, the hypervisor will a) need to be an efi binary, and b)
need to be signed with the fedora kernel-signing key. It may also need to
be
audited for any command line options that allow physical memory access or
other similar things, analogous to Matthew's kernel patch for linux.
We're still working out with rel-eng how getting things signed with that
is
going to work. I don't think there's really any necessity that it's
announced
in a proper Feature, but if you feel like going that way, that's fine too.
and from Matthew Garrett:
Right. We can conceivably sign Xen as long as it's an EFI binary, but
I'd expect that it would have to enforce secure boot itself using the
host databases.
------
So we need to get xen working with EFI, to lock xen down so it can't be
used to get around Secure Boot, and probably need to do some enforcement
of secure boot as well.
Michael Young
11 years, 4 months
Re: [Fedora-xen] [Xen-devel] Xen, Linux and EFI.
by Konrad Rzeszutek Wilk
On Wed, Jul 11, 2012 at 05:27:08PM -0400, Shriram Rajagopalan wrote:
> On Wed, Jul 11, 2012 at 4:45 PM, Konrad Rzeszutek Wilk <
> konrad.wilk(a)oracle.com> wrote:
>
> > Hey,
> >
> > There has been some discussion about EFI and SecureBoot and such.
> >
> > Most of the time I get questions in the form of "How do I get Fedora 17
> > with Xen to do EFI", I am going to concentrate on Fedora, but I think
> > this applies to other distros too.
> >
> > From my reading (I hadn't actually tried EFI yet), there are two ways
> > to bootup a system:
> >
> > - Using grub2.efi. Grub2 does the EFI API calls and calls the Xen
> > hypervisor
> > as if there were no EFI. This means no need for the EFI calls from
> > Linux or Xen are required).
> >
> >
> > - Using xen.efi. Xen can be built as a PE (Portable Executable) and it can
> > boot as an EFI image. Naturally you also need to provide a configuration
> > file and here are the details on it:
> > http://xenbits.xen.org/docs/unstable/misc/efi.html
> >
> > And you would also need to configure the EFI nvram to execute xen.efi
> > instead of grub2.efi.
> >
> > For the Linux side, the kernel needs to make new EFI variant hypercalls.
> > Currently the SLES kernel is capable of it. The upstream Linux kernel
> > cannot do it. There were patches proposed for it:
> > http://lists.xen.org/archives/html/xen-devel/2012-02/msg02027.html
> >
> >
> Does the Linux side dom0 kernel changes need to be done irrespective of the
> two options above ? or does it apply only for booting with xen.efi ?
I think the later only. Thought I am not sure how in the first case (GRUB2)
how the E820 is made to be passed to the hypervisor kernel.
>
> I spent a week trying to get Xen boot with grub2.efi (ubuntu 12.04).
> I ended up getting "Not enough memory to relocate domain 0".
>
> So I presume that the dom0 kernel EFI support needs to be done for both
> cases (grub2.efi and xen.efi) ?
>
>
> Additional info:
> Hardware: IBM System X server.
>
> It appeared that when booting xen under grub2.efi, xen was picking up a
> e-801 map
Huh. E801 is from the ancient days. I am a bit surprised that grub2.efi would
manufacture such ancient map.
So just to make sure I am not confused - you ran GRUB2 and ran with the
normal hypervisor and Linux kernel. What did you serial output look like?
> instead of the e-820 map that was on the system. I forced xen code to a
> multiboot
> e-820 map instead of the native one ( based on a forum post I saw).
> That didnt help much.
What does the memory map look like when you booted with GRUB2.efi + Linux.
Was the memory map the same or different? I am trying to figure out if
the issue is that Xen needs extra code to deal with a GRUB2 manufactured
E801 map - and that the baremetal kernel already has such logic.
>
> So I ended up booting with a SLES kernel. Not even sure if opensuse 12.1
> will work.
With what hypervisor? Same one you used when you tried GRUB2 with Xen earlier?
>
>
> which were mostly ports of how SLES did it (And they should reflect
> > the proper ownership, which they don't have right now).
> >
> > The EFI maintainer (Matthew) commented
> > http://lists.xen.org/archives/html/xen-devel/2012-02/msg00815.html
> > that he would like a better abstraction model for it. Mainly to
> > push those calls deeper down (so introduce the registration in the
> > the efi_calls). Or perhaps by providing in
> > boot_params.efi_info.efi_systab
> > a finely crafted structure pointing to Linux functions that would
> > do the hypercalls.
> >
> > And there you have it. In other words it needs somebody willing to
> > look at the patches as a baseline and do some exciting new work.
> > I sadly don't have right now the time to address this :-(
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel(a)lists.xen.org
> > http://lists.xen.org/xen-devel
> >
11 years, 4 months
Xen, Fedora, and UEFI Secure Boot
by Dario Faggioli
Hi everyone,
First of all, apologizes if the issue has been discussed already (I
joined only a couple of months ago), but I was wondering whether there
already are plans on how to support that UEFI Secure Boot crazy (and
I've been gentle :-P) thing from the point of view of the xen packages
on Fedora.
I mean, is some sort of binary signing involved? If so, are we already
able to do it, or at least will we be able to take advantage of whatever
Fedora will do with kernel images? Or is there something
different/special we should consider?
I'm not at all an expert of the matter, I was just reading about it and
started wondering whether it would still be possible to have xen binary
packages for Fedora (and of course for other distros too)...
Some of the links I found about the subject:
http://mjg59.dreamwidth.org/5552.html
https://lists.ubuntu.com/archives/ubuntu-devel/2012-June/035445.html
Thanks and Regards,
Dario
--
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://retis.sssup.it/people/faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)
11 years, 4 months
