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

[Alon Levy]

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.

> 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:
>