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

[Anthony Liguori <anthony@codemonkey.ws>]

On 11/27/2011 07:04 AM, Avi Kivity wrote:
> On 11/24/2011 08:03 PM, Luiz Capitulino wrote:
>> Avi,
>>
>> 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<avi@redhat.com>
>> Date:   Wed Nov 9 15:44:36 2011 +0200
>>
>>      i386: derive '-cpu host' from KVM_GET_SUPPORTED_CPUID
>>
>
> Strange, since it looks like cpuid 1 (ebx) returns the correct APIC ID.
>
> Anthony, I think we should revert that commit and refactor cpuid for
> 1.1.  The logic is spread over too many places which makes it hard to
> reason about.

Ack.

Regards,

Anthony Liguori

>