Re: [Qemu-devel] [BUG 1.0] -cpu host breaks linux guest boot

[Alon Levy]

On Fri, Nov 25, 2011 at 12:37:04PM -0200, Luiz Capitulino wrote:
> On Fri, 25 Nov 2011 16:12:37 +0200
> Alon Levy <address@hidden> wrote:
> 
> > On Thu, Nov 24, 2011 at 04:03:55PM -0200, Luiz Capitulino wrote:
> > > Avi,
> > > 
> > 
> > I have the same panic and the same bisection result. It doesn't happen
> > with recent (3.2.0 rc1 and rc3) kernels.
> 
> Would be nice to test a recent kernel with 66e3dd9 reverted. It'll be funny
> if it fails :)

It doesn't - a recent kernel doesn't care. I'm using 3.2.0-rc3
(f1e652b).

With 66e3dd9 reverted:
 3.2.0 (66e3dd9 but also an rc1 commit I used before rebasing yesterday)
  passes
 3.1.0-5 passes
 3.1.1-1 passes

Normally (not reverted):
 3.2.0 (66e3dd9) passes
 3.1.0-5 fails
 3.1.1-1 fails

> 
> > 
> > > I'm getting the following panic very early on boot on a F16 VM (latest
> > > qemu.git head 40897c9):
> > > 
> > > [    0.068018] Kernel panic - not syncing: Boot APIC ID in local APIC 
> > > unexpected (-1 vs 0)
> > > [    0.070006] Pid: 1, comm: swapper Not tainted 3.1.0-7.fc16.x86_64 #1
> > > [    0.071004] Call Trace:
> > > [    0.072035]  [<ffffffff814acb8e>] panic+0x91/0x1a5
> > > [    0.073027]  [<ffffffff81b831ca>] native_smp_prepare_cpus+0x24c/0x300
> > > [    0.075010]  [<ffffffff81b76c0d>] kernel_init+0x85/0x158
> > > [    0.075993]  [<ffffffff810527eb>] ? schedule_tail+0x27/0x6c
> > > [    0.076017]  [<ffffffff814be5f4>] kernel_thread_helper+0x4/0x10
> > > [    0.077022]  [<ffffffff81b76b88>] ? start_kernel+0x3b6/0x3b6
> > > [    0.078009]  [<ffffffff814be5f0>] ? gs_change+0x13/0x13
> > > 
> > > After some debugging and I found out that this only happens when '-cpu 
> > > host'
> > > is passed, and according to git bisect it's caused by the following 
> > > commit:
> > > 
> > > commit 66e3dd9282141b5ae75637c9676002cf3ceeb988
> > > Author: Avi Kivity <address@hidden>
> > > Date:   Wed Nov 9 15:44:36 2011 +0200
> > > 
> > >     i386: derive '-cpu host' from KVM_GET_SUPPORTED_CPUID
> > > 
> > > Not sure if this is important, but here's procinfo information about
> > > one of my host's cpus:
> > > 
> > > processor : 0
> > > vendor_id : GenuineIntel
> > > cpu family        : 6
> > > model             : 23
> > > model name        : Intel(R) Core(TM)2 Duo CPU     T9600  @ 2.80GHz
> > > stepping  : 6
> > > cpu MHz           : 2801.000
> > > cache size        : 6144 KB
> > > physical id       : 0
> > > siblings  : 2
> > > core id           : 0
> > > cpu cores : 2
> > > apicid            : 0
> > > initial apicid    : 0
> > > fpu               : yes
> > > fpu_exception     : yes
> > > cpuid level       : 10
> > > wp                : yes
> > > flags             : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge 
> > > mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe 
> > > syscall nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni 
> > > dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm 
> > > tpr_shadow vnmi flexpriority
> > > bogomips  : 5585.87
> > > clflush size      : 64
> > > cache_alignment   : 64
> > > address sizes     : 36 bits physical, 48 bits virtual
> > > power management:
> > > 
> > 
>