From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:54566) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RMIVg-0003nZ-LK for qemu-devel@nongnu.org; Fri, 04 Nov 2011 08:04:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RMIVc-0004rL-8d for qemu-devel@nongnu.org; Fri, 04 Nov 2011 08:04:36 -0400 Received: from mail-wy0-f173.google.com ([74.125.82.173]:57830) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RMIVb-0004rG-VC for qemu-devel@nongnu.org; Fri, 04 Nov 2011 08:04:32 -0400 Received: by wyh22 with SMTP id 22so2473166wyh.4 for ; Fri, 04 Nov 2011 05:04:31 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <4EB3B618.1060302@adacore.com> 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> Date: Fri, 4 Nov 2011 12:04:30 +0000 Message-ID: From: Stefan Hajnoczi Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] GSoC mentor summit QEMU users session List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fabien Chouteau Cc: =?ISO-8859-1?Q?Llu=EDs_Vilanova?= , Alexander Graf , "qemu-devel@nongnu.org Developers" On Fri, Nov 4, 2011 at 9:53 AM, Fabien Chouteau wrot= e: > 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. =A0I 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/gnatcovera= ge/ 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. >> 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. I'm trying to see if you want to send QEMU changes upstream? Stefan