From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35686) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1coQrT-0003LP-1q for qemu-devel@nongnu.org; Thu, 16 Mar 2017 04:34:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1coQrP-0005l3-Sz for qemu-devel@nongnu.org; Thu, 16 Mar 2017 04:34:19 -0400 Received: from mail.ispras.ru ([83.149.199.45]:35106) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1coQrP-0005kK-I2 for qemu-devel@nongnu.org; Thu, 16 Mar 2017 04:34:15 -0400 From: "Pavel Dovgalyuk" References: <20170307155054.5833-1-alex.bennee@linaro.org> <001801d29bf5$dcba37d0$962ea770$@ru> <8760jdqpv2.fsf@linaro.org> <000101d29cbc$b8df1ca0$2a9d55e0$@ru> <87tw6vq43b.fsf@linaro.org> In-Reply-To: <87tw6vq43b.fsf@linaro.org> Date: Thu, 16 Mar 2017 11:34:06 +0300 Message-ID: <000001d29e30$138e5700$3aab0500$@ru> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Language: ru Subject: Re: [Qemu-devel] [PATCH v3 00/11] MTTCG fix-ups for 2.9 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?utf-8?Q?'Alex_Benn=C3=A9e'?= Cc: peter.maydell@linaro.org, rth@twiddle.net, pbonzini@redhat.com, qemu-devel@nongnu.org, mttcg@listserver.greensocs.com, fred.konrad@greensocs.com, a.rigo@virtualopensystems.com, cota@braap.org, bobby.prani@gmail.com, nikunj@linux.vnet.ibm.com > From: Alex Benn=C3=A9e [mailto:alex.bennee@linaro.org] > Pavel Dovgalyuk writes: > >> From: Alex Benn=C3=A9e [mailto:alex.bennee@linaro.org] > >> Pavel Dovgalyuk writes: > >> >> From: mttcg-request@listserver.greensocs.com [mailto:mttcg- > >> request@listserver.greensocs.com] > >> >> > >> >> The next thing on my list it to look at the icount problems and = review > >> >> Paolo's fixes for it. However those fixes should go in a = separate > >> >> series and I assume via Paolo's tree. > >> > > >> > Do you mean those problems that completely broke icount? > >> > >> Completely broke is a bit strong. Certainly I tested icount on my > >> patches but I missed the pathological failure mode that led to the > >> interaction between the BQL lock breaking patch and running a real > >> guest. It didn't break icount so much as slow down guests so much = they > >> never got round to finishing their IRQ handling. > > > > That might look as slowing down in regular icount mode. > > But it becomes non-deterministic in record/replay mode. > > Therefore none of the recorded scenarios may be replayed. > > > > I tried the simplest command lines: > > > > qemu-system-i386.exe -icount = shift=3D7,rr=3Drecord,rrfile=3Dreplay.bin -net > > none >=20 > Running this against 2421f381dc (pre-merge of MTTCG) from the source > tree generates no output. My command is on Linux: >=20 > /x86_64-softmmu/qemu-system-x86_64 -icount = shift=3D7,rr=3Drecord,rrfile=3Dreplay.bin -net none >=20 > Do I need to specify the BIOS manually? No, this command line works well for me. BIOS executes and shows some = messages. Do you have any graphical output for QEMU? > > qemu-system-i386.exe -icount = shift=3D7,rr=3Dreplay,rrfile=3Dreplay.bin -net none > > > > First one was used to record execution until BIOS will print its = startup info. > > The second one is for replay, but it can replay about 200000 = instructions > > until the problems with icount manifest itself - the execution does > > not proceed. >=20 > What error message does it give? How do you know how many instructions > have been executed? It hangs after executing about 200000 instructions. I checked -d exec logs. > I ran the following test on both pre-mttcg-merge and my current HEAD > which includes Paolo's fix series: >=20 > ./arm-softmmu/qemu-system-arm -machine type=3Dvirt \ > -display none -smp 1 -m 4096 -cpu cortex-a15 \ > -kernel ../images/aarch32-current-linux-initrd-guest.img > -append "console=3DttyAMA0" -serial mon:stdio \ > -net none \ > -icount shift=3D7,rr=3Drecord,rrfile=3Dreplay.bin >=20 > And then: >=20 > ./arm-softmmu/qemu-system-arm -machine type=3Dvirt \ > -display none -smp 1 -m 4096 -cpu cortex-a15 \ > -kernel ../images/aarch32-current-linux-initrd-guest.img > -append "console=3DttyAMA0" -serial mon:stdio \ > -net none \ > -icount shift=3D7,rr=3Dreplay,rrfile=3Dreplay.bin >=20 > And they both ran the same. However I kept running into: >=20 > [ 3.542408] RPC: Registered tcp NFSv4.1 backchannel transport = module. > qemu-system-arm: Missing character write event in the replay log >=20 > This seems to be a pre-existing Does it mean that qemu-arm platform includes some serial devices that = were not detected by the replay? Pavel Dovgalyuk