From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32EDFC43461 for ; Tue, 8 Sep 2020 13:02:32 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C159922597 for ; Tue, 8 Sep 2020 13:02:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="vdfJsDnd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C159922597 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56634 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kFdGY-0005f4-VG for qemu-devel@archiver.kernel.org; Tue, 08 Sep 2020 09:02:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43558) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kFdFl-0004lq-Iu for qemu-devel@nongnu.org; Tue, 08 Sep 2020 09:01:41 -0400 Received: from mail-wr1-x443.google.com ([2a00:1450:4864:20::443]:44072) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kFdFj-0003zA-5S for qemu-devel@nongnu.org; Tue, 08 Sep 2020 09:01:41 -0400 Received: by mail-wr1-x443.google.com with SMTP id s12so633515wrw.11 for ; Tue, 08 Sep 2020 06:01:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=references:user-agent:from:to:cc:subject:in-reply-to:date :message-id:mime-version:content-transfer-encoding; bh=8FyJoLHgMTM2n4ZDJTEcV+3rqYOjlTykXAEfWTsNFOI=; b=vdfJsDndoXyGEwe/FPoXB0LORIBlX0LIHJAsxgUVM0KZzGcmEi7e7LiT/bHZxs2/nQ /kPIl7L8lsliqBabdcgtp2bUoCBmn4Z+cqt8VCfwo9jE4tbZ8eCvKVGE8uVhR4NcPHEf DHOBUYsymmk37Sr0lQNqKIy7aRy6da3n04fLlbYxkb0wvM2ew3n9pP+641s0oT1r2mqE ZMFojpFWUviM+NZ9vsA18hYb58GPjk8knzE6b7zcwUQekzttWkHgyp2nhKbKWnZpDq7J /SNkqEohV+5PBGCOmcwALkBe56U6ZvY3OVvSbeA4P6Y2TQKj++OSvhJXXRiQ25cs4T7y F6og== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:references:user-agent:from:to:cc:subject :in-reply-to:date:message-id:mime-version:content-transfer-encoding; bh=8FyJoLHgMTM2n4ZDJTEcV+3rqYOjlTykXAEfWTsNFOI=; b=XQRmQukdbd051nK+1+M3M1/pct67PiWkN4HrCVjm2kGmhiLRHMcpTWP2S2gDxVCy08 QaXFZm5xvKjlvGRpZ1ZpQ0tvDtK4se+Hy3nUwU4ai4+CqNkgxT5NRG8TpDJlQlkFki/I /QNwhW2WF2uB7kLTqreyuwN1MNjM7IJxVuB5T4Tqthr/QVa+4JAHWS72aTDKGAjXDB3H barm0RSNJmTMX1UnpNvMEVXYQOrAqgILIDCouvzYVlMYhBDf1kbxdBAO56J0jXYm6Hgc aOUMagvXTjSpoAObW4n+6mW+9hxdxLLOw6FgM7C41ZIFzPAyhkx7pyCOrWuJU+rZ//YN 6yAA== X-Gm-Message-State: AOAM533ri5Pu9y+1Ej9nuGNoZ5mU+nKK4iqyYv+LolhwEnQdtaaMloz8 1IGcdB/y2jWBl0dkzmKR74pvAQ== X-Google-Smtp-Source: ABdhPJwZSKExjkxfQGOprJ2eI5m2ejRko0x7C5hx9/olY67d6sO826vfoWTBAwWI1XQtW+L6cyVnlQ== X-Received: by 2002:adf:dd51:: with SMTP id u17mr26425131wrm.355.1599570088724; Tue, 08 Sep 2020 06:01:28 -0700 (PDT) Received: from zen.linaroharston ([51.148.130.216]) by smtp.gmail.com with ESMTPSA id n4sm34086074wrp.61.2020.09.08.06.01.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Sep 2020 06:01:25 -0700 (PDT) Received: from zen (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id 685791FF7E; Tue, 8 Sep 2020 14:01:24 +0100 (BST) References: <159903454714.28509.7439453309116734374.stgit@pasha-ThinkPad-X280> <159903463379.28509.561479052940546124.stgit@pasha-ThinkPad-X280> User-agent: mu4e 1.5.5; emacs 28.0.50 From: Alex =?utf-8?Q?Benn=C3=A9e?= To: Pavel Dovgalyuk Subject: Re: [PATCH v3 15/15] tests/acceptance: add reverse debugging test In-reply-to: <159903463379.28509.561479052940546124.stgit@pasha-ThinkPad-X280> Date: Tue, 08 Sep 2020 14:01:24 +0100 Message-ID: <87tuw8pgm3.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2a00:1450:4864:20::443; envelope-from=alex.bennee@linaro.org; helo=mail-wr1-x443.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, wrampazz@redhat.com, ehabkost@redhat.com, mtosatti@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, stefanha@redhat.com, crosa@redhat.com, pbonzini@redhat.com, mreitz@redhat.com, philmd@redhat.com, zhiwei_liu@c-sky.com, rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Pavel Dovgalyuk writes: > From: Pavel Dovgalyuk > > This is a test for GDB reverse debugging commands: reverse step and rever= se continue. > Every test in this suite consists of two phases: record and replay. > Recording saves the execution of some instructions and makes an initial > VM snapshot to allow reverse execution. > Replay saves the order of the first instructions and then checks that they > are executed backwards in the correct order. > After that the execution is replayed to the end, and reverse continue > command is checked by setting several breakpoints, and asserting > that the execution is stopped at the last of them. > > Signed-off-by: Pavel Dovgalyuk > --- > MAINTAINERS | 1=20 > tests/acceptance/reverse_debugging.py | 203 +++++++++++++++++++++++++++= ++++++ > 2 files changed, 204 insertions(+) > create mode 100644 tests/acceptance/reverse_debugging.py > > diff --git a/MAINTAINERS b/MAINTAINERS > index e49af700c9..76450f1bdf 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -2644,6 +2644,7 @@ F: include/sysemu/replay.h > F: docs/replay.txt > F: stubs/replay.c > F: tests/acceptance/replay_kernel.py > +F: tests/acceptance/reverse_debugging.py > F: qapi/replay.json >=20=20 > IOVA Tree > diff --git a/tests/acceptance/reverse_debugging.py b/tests/acceptance/rev= erse_debugging.py > new file mode 100644 > index 0000000000..dda42e1c1a > --- /dev/null > +++ b/tests/acceptance/reverse_debugging.py > @@ -0,0 +1,203 @@ > +# Reverse debugging test > +# > +# Copyright (c) 2020 ISP RAS > +# > +# Author: > +# Pavel Dovgalyuk > +# > +# This work is licensed under the terms of the GNU GPL, version 2 or > +# later. See the COPYING file in the top-level directory. > +import os > +import logging > + > +from avocado_qemu import BUILD_DIR > +from avocado.utils import gdb > +from avocado.utils import process > +from avocado.utils.path import find_command > +from boot_linux_console import LinuxKernelTest > + > +class ReverseDebugging(LinuxKernelTest): > + """ > + Test GDB reverse debugging commands: reverse step and reverse contin= ue. > + Recording saves the execution of some instructions and makes an init= ial > + VM snapshot to allow reverse execution. > + Replay saves the order of the first instructions and then checks tha= t they > + are executed backwards in the correct order. > + After that the execution is replayed to the end, and reverse continue > + command is checked by setting several breakpoints, and asserting > + that the execution is stopped at the last of them. > + """ > + > + timeout =3D 10 > + STEPS =3D 10 > + endian_is_le =3D True > + > + def run_vm(self, record, shift, args, replay_path, image_path): > + logger =3D logging.getLogger('replay') > + vm =3D self.get_vm() > + vm.set_console() > + if record: > + logger.info('recording the execution...') > + mode =3D 'record' > + else: > + logger.info('replaying the execution...') > + mode =3D 'replay' > + vm.add_args('-s', '-S') > + vm.add_args('-icount', 'shift=3D%s,rr=3D%s,rrfile=3D%s,rrsnapsho= t=3Dinit' % > + (shift, mode, replay_path), > + '-net', 'none') > + vm.add_args('-drive', 'file=3D%s,if=3Dnone' % image_path) > + if args: > + vm.add_args(*args) > + vm.launch() > + return vm > + > + @staticmethod > + def get_reg_le(g, reg): > + res =3D g.cmd(b'p%x' % reg) > + num =3D 0 > + for i in range(len(res))[-2::-2]: > + num =3D 0x100 * num + int(res[i:i + 2], 16) > + return num > + > + @staticmethod > + def get_reg_be(g, reg): > + res =3D g.cmd(b'p%x' % reg) > + return int(res, 16) > + > + def get_reg(self, g, reg): > + # value may be encoded in BE or LE order > + if self.endian_is_le: > + return self.get_reg_le(g, reg) > + else: > + return self.get_reg_be(g, reg) These seem a little hacky. Can't we issue normal gdb commands. In the SVE tests I use: frame =3D gdb.selected_frame() for i in range(0, 32): rname =3D "z%d" % (i) zreg =3D frame.read_register(rname) which works with the symbolic name and doesn't need endian tricks to sort it out. > + > + def get_pc(self, g): > + return self.get_reg(g, self.REG_PC) > + > + def check_pc(self, g, addr): > + pc =3D self.get_pc(g) > + if pc !=3D addr: > + self.fail('Invalid PC (read %x instead of %x)' % (pc, addr)) > + > + @staticmethod > + def gdb_step(g): > + g.cmd(b's', b'T05thread:01;') > + > + @staticmethod > + def gdb_bstep(g): > + g.cmd(b'bs', b'T05thread:01;') Hmm so these are packet commands? Can't we access via the python API? Clebb= er? > + > + @staticmethod > + def vm_get_icount(vm): > + return vm.qmp('query-replay')['return']['icount'] > + > + def reverse_debugging(self, shift=3D7, args=3DNone): > + logger =3D logging.getLogger('replay') > + > + # create qcow2 for snapshots > + logger.info('creating qcow2 image for VM snapshots') > + image_path =3D os.path.join(self.workdir, 'disk.qcow2') > + qemu_img =3D os.path.join(BUILD_DIR, 'qemu-img') > + if not os.path.exists(qemu_img): > + qemu_img =3D find_command('qemu-img', False) > + if qemu_img is False: > + self.cancel('Could not find "qemu-img", which is required to= ' > + 'create the temporary qcow2 image') > + cmd =3D '%s create -f qcow2 %s 128M' % (qemu_img, image_path) > + process.run(cmd) > + > + replay_path =3D os.path.join(self.workdir, 'replay.bin') > + > + # record the log > + vm =3D self.run_vm(True, shift, args, replay_path, image_path) > + while self.vm_get_icount(vm) <=3D self.STEPS: > + pass > + last_icount =3D self.vm_get_icount(vm) > + vm.shutdown() > + > + logger.info("recorded log with %s+ steps" % last_icount) > + > + # replay and run debug commands > + vm =3D self.run_vm(False, shift, args, replay_path, image_path) > + logger.info('connecting to gdbstub') > + g =3D gdb.GDBRemote('127.0.0.1', 1234, False, False) > + g.connect() > + r =3D g.cmd(b'qSupported') > + if b'qXfer:features:read+' in r: > + g.cmd(b'qXfer:features:read:target.xml:0,ffb') > + if b'ReverseStep+' not in r: > + self.fail('Reverse step is not supported by QEMU') > + if b'ReverseContinue+' not in r: > + self.fail('Reverse continue is not supported by QEMU') > + > + logger.info('stepping forward') > + steps =3D [] > + # record first instruction addresses > + for _ in range(self.STEPS): > + pc =3D self.get_pc(g) > + logger.info('saving position %x' % pc) > + steps.append(pc) > + self.gdb_step(g) > + > + # visit the recorded instruction in reverse order > + logger.info('stepping backward') > + for addr in steps[::-1]: > + self.gdb_bstep(g) > + self.check_pc(g, addr) > + logger.info('found position %x' % addr) > + > + logger.info('seeking to the end (icount %s)' % (last_icount - 1)) > + vm.qmp('replay-break', icount=3Dlast_icount - 1) > + # continue - will return after pausing > + g.cmd(b'c', b'T02thread:01;') > + > + logger.info('setting breakpoints') > + for addr in steps: > + # hardware breakpoint at addr with len=3D1 > + g.cmd(b'Z1,%x,1' % addr, b'OK') > + > + logger.info('running reverse continue to reach %x' % steps[-1]) > + # reverse continue - will return after stopping at the breakpoint > + g.cmd(b'bc', b'T05thread:01;') > + > + # assume that none of the first instructions is executed again > + # breaking the order of the breakpoints > + self.check_pc(g, steps[-1]) > + logger.info('successfully reached %x' % steps[-1]) > + > + logger.info('exitting gdb and qemu') > + vm.shutdown() > + > +class ReverseDebugging_X86_64(ReverseDebugging): > + REG_PC =3D 0x10 > + REG_CS =3D 0x12 > + def get_pc(self, g): > + return self.get_reg_le(g, self.REG_PC) \ > + + self.get_reg_le(g, self.REG_CS) * 0x10 > + > + def test_x86_64_pc(self): > + """ > + :avocado: tags=3Darch:x86_64 > + :avocado: tags=3Dmachine:pc > + """ > + # start with BIOS only > + self.reverse_debugging() > + > +class ReverseDebugging_AArch64(ReverseDebugging): > + REG_PC =3D 32 > + > + def test_aarch64_virt(self): > + """ > + :avocado: tags=3Darch:aarch64 > + :avocado: tags=3Dmachine:virt > + :avocado: tags=3Dcpu:cortex-a53 > + """ > + kernel_url =3D ('https://archives.fedoraproject.org/pub/archive/= fedora' > + '/linux/releases/29/Everything/aarch64/os/images/p= xeboot' > + '/vmlinuz') > + kernel_hash =3D '8c73e469fc6ea06a58dc83a628fc695b693b8493' > + kernel_path =3D self.fetch_asset(kernel_url, asset_hash=3Dkernel= _hash) > + > + self.reverse_debugging( > + args=3D('-kernel', kernel_path, '-cpu', 'cortex-a53')) Quibbles aside it's excellent to have a test that exercises the functionality. --=20 Alex Benn=C3=A9e