Re: [kvm-devel] kvm-67: kernel panic while booting debian-40r3-i386-businesscard.iso

[Avi K. <av...@qu...>]

Jan Luebbe wrote:
> Hi!
>
> I'm preparing kvm-67 for debian. While testing i noticed a problem:
>
> When booting the debian installer from the official CD [1] this problem:
>   

> Call Trace:                     
>  [<c0146d5b>] kmem_cache_create+0x15e/0x410
> Code: c3 57 56 53 89 c6 9c 5f fa 8b 08 83 39 00 74 12 c7 41 0c 01 00 00
> 00 8b 01
>  48 89 01 8b 5c 81 10 eb 07 e8 a5 fb ff ff 89 c3 57 9d <0f> 0d 0b 90 85
> db 74 1b
>  8b 56 10 31 c0 89 d1 c1 e9 02 89 df f3
> EIP: [<c01467be>] kmem_cache_zalloc+0x2a/0x53 SS:ESP 0068:c030ff80
>  <0>Kernel panic - not syncing: Attempted to kill the idle task!
>   
0f 0d 0b                prefetchw (%ebx)

This is an AMD 3Dnow! instruction, which is not supported on Intel 
processors.  I guess the 3Dnow! cpuid bit leaked in via the qemu merge.

I guess two fixes are needed:
- remove the 3Dnow! bit
- add emulation for prefetchw (easy, as it doesn't need to do anything) 
to support live migration from AMD to Intel

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.