Re: [Qemu-devel] Re: Breakage with local APIC routing

[Jan Kiszka <jan.kiszka@web.de>]

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Juergen Lock wrote:
> On Thu, Aug 27, 2009 at 07:56:41PM +0200, Jan Kiszka wrote:
>> Juergen Lock wrote:
>>> On Tue, Aug 25, 2009 at 12:38:04PM +0200, Jan Kiszka wrote:
>>>> Mohammed Gamal wrote:
>>>>> On Tue, Aug 25, 2009 at 1:16 PM, Mohammed Gamal<m.gamal005@gmail.com> wrote:
>>>>>> On Tue, Aug 25, 2009 at 12:33 PM, Jan Kiszka<jan.kiszka@web.de> wrote:
>>>>>>> Mohammed Gamal wrote:
>>>>>>>> qemu-system-x86_64 -hda /dev/null -cdrom <path_to_ubuntu_iso_image>
>>>>>>>>
>>>>>>> I only have kubuntu-9.04-alternate-amd64.iso at hand ATM, and with that
>>>>>>> image I'm unable to reproduce. Will download and check standard ubuntu
>>>>>>> later today.
>>>>>>>
>>>>>>>> I was using qemu-kvm, but I assume that using -no-kvm would be
>>>>>>>> equivalent to using plain qemu, no?
>>>>>>> Generally yes, but not necessarily (e.g. the BIOSes are different). So
>>>>>>> it's better to check such issues also against "clean" qemu, specifically
>>>>>>> as we are on qemu-devel here.
>>>>>>>
>>>>>>> Jan
>>>>>>>
>>>>>>>
>>>>>> Just tested this now on a vanilla qemu, I am still able to reproduce
>>>>>> the same issue.
>>>>>>
>>>>> This bug might be related to the same problem
>>>>> https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/379000
>>>> I think at least those issues should be solved with recent qemu and
>>>> bioses. Note that this report refers to a fairly old qemu version
>>>> (0.10.0-derived).
>>> Btw I had reported the same symptom as in that ubuntu ticket for FreeBSD 8
>>> hosts both with 0.10.6 and 0.11.0rc1 before:
>>> 	http://lists.gnu.org/archive/html/qemu-devel/2009-08/msg00396.html
>>> As mentioned in that post I was able to work around the issue by passig
>>> the linux guest kernels `no_timer_check' after which they seemed to boot up
>>> just fine, so I suspect in that case its not actually an apic routing
>>> problem but just guest timer irqs arriving late/irregularly which cause
>>> the guest kernel timer checks to time out and fail.
>> Does this happen with git head and its corresponding bios, too? I cannot
>> imagine that the FreeBSD platform is so irregularly generating timer
>> events for qemu that Linux gets unhappy during this test loop (I think
>> to remember it needs 3 out of 10 ticks or so to be satisfied).
> 
> Alright so I testwise updated the FreeBSD qemu-devel port to git head
> (db3c9e08e0d6eaf83f9d7a2c87dc45af3ac8f4dd, update at
> 	http://people.freebsd.org/~nox/qemu/qemu-devel-20090829.patch

You will have to help me isolating the reason as I don't have any BSD
host. And running recent qemu/-kvm on Linux hosts does not trigger
problems around booting ubuntu here.

> ) - and can report the problem still exists.  (btw pcap seems to be
> broken in that patch which was stll working with the 0.11 snapshot,
> will have to take care of that later...)
> 
>  Thanx,
> 	Juergen

Jan


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