Re: [Qemu-devel] Tracing drivers commands to an emulated device

[Stefan Hajnoczi]

On Tue, Jul 31, 2012 at 9:43 AM,  <address@hidden> wrote:
> I would trace the commands issued by the driver to an emulated device. I've 
> read in docs/tracing that it is possible but it is not completely clear how 
> doing that. Is it possible to place hooks inside the emulated device code? Or 
> is better tracing the in/out operations and the access to the memory mapped 
> zone?

Device-specific trace events can provide you more information like the
device's operating state.

Generic trace events like pio/mmio only tell you the address and data
that the guest is reading/writing.

Which is best depends on what you are doing.  If you want to observe a
specific device I recommend enabling its device-specific trace events
or adding new ones.

If you add trace events and think they may be useful to others, please
submit patches.  For more information, see
http://wiki.qemu.org/Contribute/SubmitAPatch.

Stefan