Re: Issue about domU missing interrupt

Mats Petersson
Mon, 03 Dec 2012 13:19:47 -0000

On 03/12/12 13:14, G.R. wrote:
> On Mon, Dec 3, 2012 at 6:15 PM, Mats Petersson
> <mats.petersson@citrix.com <mailto:mats.petersson@citrix.com>>
wrote:
>
>     On 03/12/12 03:47, G.R. wrote:
>
>         Hi developers,
>         I met some domU issues and the log suggests missing interrupt.
>         Details from here:
>         http://www.gossamer-threads.com/lists/xen/users/263938#263938
>         In summary, this is the suspicious log:
>
>         (XEN) vmsi.c:122:d32767 Unsupported delivery mode 3
>
>         I''ve checked the code in question and found that mode 3 is
an
>         ''reserved_1'' mode.
>         I want to trace down the source of this mode setting to
>         root-cause the issue.
>         But I''m not an xen developer, and am even a newbie as a
xen user.
>         Could anybody give me instructions about how to enable
>         detailed debug log?
>         It could be better if I can get advice about experiments to
>         perform / switches to try out etc.
>
>         My SW config:
>         dom0: Debian wheezy (3.6 experimental kernel, xen 4.1.3-4)
>         domU: Debian wheezy 3.2.x stock kernel.
>
>         Thanks,
>         Timothy
>
>     Are you passing hardware (PCI Passthrough) to the HVM guest?
>     What are the exact messages in the DomU?
>
>
> Yes, I''m doing PCI passthrough (the IGD, audio && USB
controller).
> But this is actually a PVHVM guest since debian stock kernel has PVOP
> enabled.
> And when I tried another PVOP disabled linux distro (openelec v2.0), I
> did not see such msi related error message.
> Actually, with that domU I do not see anything obvious wrong from the
> log, but I also see nothing from panel (panel receive no signal and go
> power-saving) :-(
>
>
> Back to the issue I was reporting, the domU log looks like this:
>
> Dec 2 21:52:44 debvm kernel: [ 1085.604071]
> [drm:i915_hangcheck_ring_idle]
> *ERROR* Hangcheck timer elapsed... blt ring idle [waiting on 3354, at
> 3354], missed IRQ?
> Dec 2 21:56:50 debvm kernel: [ 1332.076071]
> [drm:i915_hangcheck_ring_idle]
> *ERROR* Hangcheck timer elapsed... render ring idle [waiting on 11297, at
> 11297], missed IRQ?
> Dec 2 22:32:48 debvm kernel: [ 7.220073] hda-intel: azx_get_response
> timeout, switching to polling mode: last cmd=0x000f0000
> Dec 2 22:45:32 debvm kernel: [ 776.392084] hda-intel: No response from
> codec, disabling MSI: last cmd=0x002f0600
> Dec 2 22:45:33 debvm kernel: [ 777.400075] hda_intel: azx_get_response
> timeout, switching to single_cmd mode: last cmd=0x002f0600
>
>
> Thanks,
> Timothy
It does sound like there is a fix in 4.2.0, as indicated by Jan, that
fixes this. I''m not fully clued up to what the policy for backporting
fixes are, and I haven''t looked at the complexity of the fix itself,
but
either updating to the 4.2.0 or a (personal) backport sounds like the
right solution here.

Unfortunately, I hadn''t seen Jan''s reply by the time I wrote
my response
to your original email.

--
Mats