From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:34979) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RMKsb-0005F4-KE for qemu-devel@nongnu.org; Fri, 04 Nov 2011 10:36:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RMKsa-0000Vg-59 for qemu-devel@nongnu.org; Fri, 04 Nov 2011 10:36:25 -0400 Received: from mel.act-europe.fr ([194.98.77.210]:54361) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RMKsZ-0000VU-Ri for qemu-devel@nongnu.org; Fri, 04 Nov 2011 10:36:24 -0400 Message-ID: <4EB3F85C.6010709@adacore.com> Date: Fri, 04 Nov 2011 15:36:12 +0100 From: Fabien Chouteau MIME-Version: 1.0 References: <4639B135-B96A-43A0-B4FA-6DDCBE3FBA92@suse.de> <4EB1805F.6030701@adacore.com> <4EB26060.4060003@adacore.com> <20111104083652.GA5048@stefanha-thinkpad.localdomain> <4EB3B618.1060302@adacore.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] GSoC mentor summit QEMU users session List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: =?ISO-8859-1?Q?Llu=EDs_Vilanova?= , Alexander Graf , "qemu-devel@nongnu.org Developers" On 04/11/2011 13:04, Stefan Hajnoczi wrote: > On Fri, Nov 4, 2011 at 9:53 AM, Fabien Chouteau wrote: >> On 04/11/2011 09:36, Stefan Hajnoczi wrote: >>> 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 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. >> >> It's not rocket science but for MC/DC you have to log history of >> branches (taken or not), but if you record everything the output will >> unreasonably grow. >> >>> >>> 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. >> >> What script are you talking about? GNATcoverage is far more complex than >> a fancy script :) > > I'm not up to speed on GNATcoverage or couverture, so apologies if I'm > wrong - please let me know. Still, I think we're talking about the > same thing here: > > http://www.adacore.com/home/products/gnatpro/add-on_technologies/gnatcoverage/ > > Looks like GNATemulator is QEMU with additional instrumentation. > GNATcoverage takes the execution traces that the instrumented QEMU > produced. So when I said "fancy analysis scripts", I meant the tool > that analyzes the trace. > In your previous message you seemed to say that GNATcoverage could be included in Qemu. I just wanted to explain that GNATcoverage is a project on its own and will not be a part of Qemu. >>> On the train, can't access the PDF you mentioned right now. >> >> Can't you checkout the repository? > > Sorry, I was reading/replying to mail offline. I now grabbed the git > repo and looked at commit b82469c906829865693b4fad0edb0a069604a8d9, > which I believe is the main change needed to add couverture tracing to > QEMU. Right this is the main commit, there are few others to fix corner cases. > > I'm trying to see if you want to send QEMU changes upstream? As I said it's in our plan, but we don't have time for now. You are welcome to help if you want to. -- Fabien Chouteau