Re: [Qemu-devel] possible regression in qemu-kvm 0.13.0 (memtest)

[Peter Lieven]

Am 23.12.2010 um 03:42 schrieb Stefan Hajnoczi:

> On Wed, Dec 22, 2010 at 10:02 AM, Peter Lieven <address@hidden> wrote:
>> If I start a VM with the following parameters
>> qemu-kvm-0.13.0 -m 2048 -smp 2 -monitor tcp:0:4014,server,nowait -vnc :14 
>> -name 'ubuntu.test'  -boot order=dc,menu=off  -cdrom 
>> ubuntu-10.04.1-desktop-amd64.iso -k de
>> 
>> and select memtest in the Ubuntu CD Boot Menu, the VM immediately resets. 
>> After this reset there happen several errors including graphic corruption or 
>> the qemu-kvm binary
>> aborting with error 134.
>> 
>> Exactly the same scenario on the same machine with qemu-kvm-0.12.5 works 
>> flawlessly.
>> 
>> Any ideas?
> 
> You could track down the commit which broke this using git-bisect(1).
> The steps are:
> 
> $ git bisect start v0.13.0 v0.12.5
> 
> Then:
> 
> $ ./configure [...] && make
> $ x86_64-softmmu/qemu-system-x86_64 -m 2048 -smp 2 -monitor
> tcp:0:4014,server,nowait -vnc :14 -name 'ubuntu.test'  -boot
> order=dc,menu=off  -cdrom ubuntu-10.04.1-desktop-amd64.iso -k de
> 
> If memtest runs as expected:
> $ git bisect good
> otherwise:
> $ git bisect bad
> 
> Keep repeating this and you should end up at the commit that introduced the 
> bug.

this was the outcome of my bisect session:

956a3e6bb7386de48b642d4fee11f7f86a2fcf9a is first bad commit
commit 956a3e6bb7386de48b642d4fee11f7f86a2fcf9a
Author: Blue Swirl <address@hidden>
Date:   Sat May 22 07:59:01 2010 +0000

    Compile pckbd only once
    
    Use a qemu_irq to indicate A20 line changes. Move I/O port 92
    to pckbd.c.
    
    Signed-off-by: Blue Swirl <address@hidden>

:100644 100644 acbaf227455f931f3ef6dbe0bb4494c6b41f2cd9 
1a33d4eb4a5624c55896871b5f4ecde78a49ff28 M      Makefile.objs
:100644 100644 a22484e1e98355a35deeb5038a45fb8fe8685a91 
ba5147fbc48e4faef072a5be6b0d69d3201c1e18 M      Makefile.target
:040000 040000 dd03f81a42b5162c93c40c517f45eb9f7bece93c 
309f472328632319a15128a59715aa63daf4d92c M      default-configs
:040000 040000 83201c4fcde2f592a771479246e0a33a8906515b 
b1192bce85f2a7129fb19cf2fe7462ef168165cb M      hw
bisect run success



> 
> Stefan