Pkg xen devel - Aug 2015 - Bug#795330: Suggests noapic but doesn't support it

Package: xen-hypervisor-4.5-amd64
Severity: normal

Hi,
when running xen inside of kvm the hypervisor fails to set up the proper
IRQ routing and suggests to use noapic. If you add this via

    GRUB_CMDLINE_XEN_DEFAULT

it will boot futher but then report that noapic isn't supported.

So please make Xen not claim to support noapic if it doesn't (the issue
was finally resolved by removeing all virtion devices and doubling the
hypervisors RAM so the suggestion was misplaced anyways).
Cheers,
 -- Guido

Control: tag -1 upstream 

Jan/Andy & David,

Is there anything we can improve here on either the Xen or kernel side do
you think?

On Thu, 2015-08-13 at 00:59 +0200, Guido G?nther wrote:
> Package: xen-hypervisor-4.5-amd64
> Severity: normal
> 
> Hi,
> when running xen inside of kvm the hypervisor fails to set up the proper
> IRQ routing and suggests to use noapic.
FTR, it seems to say:

    panic("IO-APIC + timer doesn't work!  Boot with
apic_verbosity=debug "
          "and send a report.  Then try booting with the 'noapic'
option");

Did you also try the first thing it suggested? What was the result?
>  If you add this via
> 
>     GRUB_CMDLINE_XEN_DEFAULT
> 
> it will boot futher but then report that noapic isn't supported.
Is this the kernel saying that or Xen? Do you have full boot logs?

I think it is the kernel since I can't find such a message in Xen and 
http://xenbits.xen.org/docs/unstable/misc/xen-command-line.html says for
the noapic option: "This is not recommended with pvops type kernels."
> So please make Xen not claim to support noapic if it doesn't
I think ultimately this is down to different components being able to
support different things, e.g. Xen's advice might be fine with a FreeBSD
dom0 or some other version of Linux.
>  (the issue
> was finally resolved by removeing all virtion devices and doubling the
                                        ^virtio ?
> hypervisors RAM so the suggestion was misplaced anyways).
I can see how the virtio thing might make the KVM guest look different to
Xen, but the RAM thing seems orthogonal.

Thanks,
Ian.

Processing control commands:
> tag -1 upstream
Bug #795330 [xen-hypervisor-4.5-amd64] Suggests noapic but doesn't support
it
Added tag(s) upstream.

-- 
795330: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=795330
Debian Bug Tracking System
Contact owner at bugs.debian.org with problems

Your message dated Fri, 04 Sep 2015 14:38:24 +0100
with message-id <1441373904.26292.509.camel at debian.org>
has caused the   report #795330,
regarding Suggests noapic but doesn't support it
to be marked as having been forwarded to the upstream software
author(s) xen-devel at lists.xen.org, Jan Beulich <jbeulich at suse.com>,
Andrew Cooper  <andrew.cooper3 at citrix.com>, David.Vrabel at citrix.com

(NB: If you are a system administrator and have no idea what this
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-- 
795330: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=795330
Debian Bug Tracking System
Contact owner at bugs.debian.org with problems
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From: Ian Campbell <ijc at debian.org>
Subject: Re: [Pkg-xen-devel] Bug#795330: Suggests noapic but doesn't support
it
Date: Fri, 04 Sep 2015 14:38:24 +0100
Size: 3544
URL:
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On 04/09/15 14:38, Ian Campbell wrote:
> Control: tag -1 upstream 
> 
> Jan/Andy & David,
> 
> Is there anything we can improve here on either the Xen or kernel side do
> you think?
> 
> On Thu, 2015-08-13 at 00:59 +0200, Guido G?nther wrote:
>> Package: xen-hypervisor-4.5-amd64
>> Severity: normal
>>
>> Hi,
>> when running xen inside of kvm the hypervisor fails to set up the
proper
>> IRQ routing and suggests to use noapic.
> 
> FTR, it seems to say:
> 
>     panic("IO-APIC + timer doesn't work!  Boot with
apic_verbosity=debug "
>           "and send a report.  Then try booting with the
'noapic' option");
This is the Linux kernel making a recommendation for its command line.
> Did you also try the first thing it suggested? What was the result?
> 
>>  If you add this via
>>
>>     GRUB_CMDLINE_XEN_DEFAULT
>>
>> it will boot futher but then report that noapic isn't supported.
Don't add Linux command line options to the Xen command line.

David