Re: [Qemu-devel] Tracing message for mu

[Charles . Tsai-蔡清海-研究發展部]

Stefan,

Hans replied me back and he suggested me to use strace.
Hopefully, this issue can be resolved.

Additionally, we encountered a tough issue right now.
When we ran a 64-bit Windows 7 VM overnight, the kvm process was killed for 
some reasons.

Here is the qemu version I copied from the screen

"QEMU emulator version 1.0 (qemu-kvm-devel), Copyright (c) 2003-2008 Fabrice 
Bellard"

The Qemu source is from Hans. Any suggestion to attack this issue?


-----Original Message-----
From: Stefan Hajnoczi [mailto:address@hidden 
Sent: Friday, May 25, 2012 4:13 PM
To: Charles.Tsai-蔡清海-研究發展部
Cc: address@hidden; Jonah.Wu-吳君勉-研究發展部; Hans de Goede
Subject: Re: Tracing message for mu

On Fri, May 25, 2012 at 3:42 AM, Charles.Tsai-蔡清海-研究發展部
<address@hidden> wrote:
> I had a problem to launch the VM using the script that contains the Qemu 
> options. My script used to work before updating the latest Qemu code 
> suggested by Hans. I also tried to latest code from Freedesktop, it still 
> failed to work either.
> Obviously, Qemu was broken somewhere in the code. I did try to check the log 
> file of the Qemu and it seemed to be not quite helpful.
>
> In this case, how do I turn on the Qemu trace to see where the code failed? 
> From the Qemu document, I cannot find anything talking about this. Please 
> give me a suggestion so that I can probe this issue here.

Please provide details when asking for help:
1. The full QEMU command-line used to launch the guest.
2. The exact error message and where it was printed (inside the guest or by 
QEMU itself).
3. Which version of QEMU or which git commit you are testing.

Since you mentioned Hans and Freedesktop I guess this has something to do with 
SPICE and QXL.

QEMU tracing does not provide much debug info on startup - it's more useful 
once the guest is running and you need to understand the I/O requests and other 
operations that are going on.  There is a quickstart guide in docs/tracing.txt 
if you want to try it.

Stefan