Re: [Qemu-devel] memory trace with qemu

[Stefan Hajnoczi <stefanha@gmail.com>]

On Fri, Jul 23, 2010 at 8:34 AM, Jun Koi <junkoi2004@gmail.com> wrote:
> On Fri, Jul 23, 2010 at 3:15 PM, Stefan Hajnoczi <stefanha@gmail.com> wrote:
>> On Fri, Jul 23, 2010 at 4:12 AM, Mulyadi Santosa
>> <mulyadi.santosa@gmail.com> wrote:
>>> Hi...
>>>
>>> On Fri, Jul 23, 2010 at 05:30, Eduardo Cruz <eduardohmdacruz@gmail.com> wrote:
>>>> Hello, I need qemu to keep track of all the memory access made by the guest,
>>>> including read, write and the instruction fetches.
>>>
>>> AFAIK there are lots of experiments on this and has produces working
>>> patches...at least from the posting of the creator. There is even a
>>> patch floating to start creating trace framework a while ago.
>>
>> Thanks Mulyadi, I think you are referring to the tracing work that
>> Prerna Saxena and I are doing.  Here is the documentation:
>>
>> http://repo.or.cz/w/qemu/stefanha.git/blob/tracing:/docs/tracing.txt
>>
>> The patches apply to qemu.git.  You can define trace events in the
>> trace-events file and then call them from places in the code.  There
>> is a script to pretty-print the binary trace file that QEMU produces.
>>
>
> what trace events do you support now?

The existing set of trace events is here:

http://repo.or.cz/w/qemu/stefanha.git/blob/tracing:/trace-events

It is a limited set of pre-defined trace events - most come from my
block latency tracing work.  But adding trace events is easy.

There is a task on the roadmap to get broader tracing coverage before
submitting the patches to qemu.git.  If you add trace events that you
feel would be useful to others, please don't hesitate to send patches
so they can be included.

Stefan

> thanks,
> J
>