Re: [Xen-devel] [BUG] panic: "IO-APIC + timer doesn't work" - several people have reproduced

From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jason Andryuk <jandryuk@gmail.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
	Aaron Janse <aaron@ajanse.me>, Jan Beulich <jbeulich@suse.com>
Subject: Re: [Xen-devel] [BUG] panic: "IO-APIC + timer doesn't work" - several people have reproduced
Date: Tue, 18 Feb 2020 21:45:22 +0000	[thread overview]
Message-ID: <ea7cba55-f267-09c5-044e-e8947a6d2900@citrix.com> (raw)
In-Reply-To: <CAKf6xpt26=s_+cD63VJ1Cp3WZvtq3p673uUiqiuDHAVH=ZJOcQ@mail.gmail.com>

On 18/02/2020 18:43, Jason Andryuk wrote:
> On Mon, Feb 17, 2020, 8:22 PM Andrew Cooper <andrew.cooper3@citrix.com> wrote:
>> On 17/02/2020 20:41, Jason Andryuk wrote:
>>> On Mon, Feb 17, 2020 at 2:46 PM Andrew Cooper <andrew.cooper3@citrix.com> wrote:
>>>> On 17/02/2020 19:19, Jason Andryuk wrote:
>>>>> enabling vecOn Tue, Dec 31, 2019 at 5:43 AM Aaron Janse <aaron@ajanse.me> wrote:
>>>>>> On Tue, Dec 31, 2019, at 12:27 AM, Andrew Cooper wrote:
>>>>>>> Is there any full boot log in the bad case?  Debugging via divination
>>>>>>> isn't an effective way to get things done.
>>>>>> Agreed. I included some more verbose logs towards the end of the email (typed up by hand).
>>>>>>
>>>>>> Attached are pictures from a slow-motion video of my laptop booting. Note that I also included a picture of a stack trace that happens immediately before reboot. It doesn't look related, but I wanted to include it anyway.
>>>>>>
>>>>>> I think the original email should have said "4.8.5" instead of "4.0.5." Regardless, everyone on this mailing list can now see all the boot logs that I've seen.
>>>>>>
>>>>>> Attaching a serial console seems like it would be difficult to do on this laptop, otherwise I would have sent the logs as a txt file.
>>>>> I'm seeing Xen panic: "IO-APIC + timer doesn't work" on a Dell
>>>>> Latitude 7200 2-in-1.  Fedora 31 Live USB image boots successfully.
>>>>> No way to get serial output.  I manually recreated the output before
>>>>> from the vga display.
>>>> We have multiple bugs.
>>>>
>>>> First and foremost, Xen seems totally broken when running in ExtINT
>>>> mode.  This needs addressing, and ought to be sufficient to let Xen
>>>> boot, at which point we can try to figure out why it is trying to fall
>>>> back into 486(ish) compatibility mode.
> Xen has "enabled ExtINT on CPU#0" while linux has "masked ExtINT on
> CPU#0" so linux isn't using ExtINT?

It would appear not.  Even more concerningly, on my Kabylake box,

# xl dmesg | grep ExtINT
(XEN) enabled ExtINT on CPU#0
(XEN) masked ExtINT on CPU#1
(XEN) masked ExtINT on CPU#2
(XEN) masked ExtINT on CPU#3
(XEN) masked ExtINT on CPU#4
(XEN) masked ExtINT on CPU#5
(XEN) masked ExtINT on CPU#6
(XEN) masked ExtINT on CPU#7

which at first glance suggests that we have something asymmetric being
set up.

~Andrew

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