Stefan Hajnoczi writes: > On Thu, Nov 03, 2011 at 10:35:28AM +0100, Fabien Chouteau wrote: >> On 03/11/2011 08:44, Stefan Hajnoczi wrote: >> > On Wed, Nov 2, 2011 at 5:39 PM, Fabien Chouteau <chout...@adacore.com> >> > wrote: >> >> On 29/10/2011 15:52, Alexander Graf wrote: >> > I took a quick peak at the qemu-trace.[ch] from couverture and it >> > looks along the lines of the instrumentation that others have been >> > doing too. I hope you have time to propose the coverage >> > instrumentation for upstream QEMU. >> > >> >> I don't know much about other instrumentations in Qemu (pointers are >> welcome :), but what we have in couverture-qemu is not trivial, >> especially when it comes to MC/DC analysis. You should take a look at >> 201005-erts2.pdf if you want technical details.
> My impression was that the QEMU portion of instrumentation was fairly > simple - it writes out trace records at various interesting points > during guest execution in TCG. > I think fancy analysis scripts do not have to be part of QEMU but they > could be added to scripts/ or put in a new contrib/ directory. I've only had a brief look into the changes, but I think the mechanism I implemented has a cleaner fit into QEMU, thanks to previous feedback from this list. It explicitly separates the tracing mechanism (in QEMU itself) from the specific trace analysis (which resides in a separate library specified by the user at compile time, where most of couverture would go). On the other hand, I have a complementary set of events, so we can definitely join the efforts on that side (e.g., I haven't yet went into the trouble of adding the begin/end TB or branch events). I have only managed to send the most general changes that are needed before having the full-fledged instrumentation, but if there's no opposition on having this kind of feature I will start sending the rest once mainline opens up again (which I believe won't take much more time). Lluis -- "And it's much the same thing with knowledge, for whenever you learn something new, the whole world becomes that much richer." -- The Princess of Pure Reason, as told by Norton Juster in The Phantom Tollbooth