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

[Juergen Lock]

On Mon, Aug 31, 2009 at 09:47:27AM +0200, Jan Kiszka wrote:
> 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<address@hidden> wrote:
> >>>>>> On Tue, Aug 25, 2009 at 12:33 PM, Jan Kiszka<address@hidden> 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.

Well I don't quite know where to start looking, of course I'd be
happy to test patches... :)

 Thanx,
        Juergen