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=-5.5 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 4786CC2D0C0 for ; Mon, 23 Dec 2019 09:47:26 +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 1815920709 for ; Mon, 23 Dec 2019 09:47:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1815920709 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55202 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ijKJA-0003GE-RL for qemu-devel@archiver.kernel.org; Mon, 23 Dec 2019 04:47:24 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:45040) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ijKHt-0002ZJ-A5 for qemu-devel@nongnu.org; Mon, 23 Dec 2019 04:46:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ijKHr-00035I-RD for qemu-devel@nongnu.org; Mon, 23 Dec 2019 04:46:05 -0500 Received: from mail.ispras.ru ([83.149.199.45]:50610) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ijKHr-0002iR-Aj for qemu-devel@nongnu.org; Mon, 23 Dec 2019 04:46:03 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 9F9C754006B; Mon, 23 Dec 2019 12:45:49 +0300 (MSK) Subject: [for-5.0 PATCH 00/11] Support for reverse debugging with GDB From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Mon, 23 Dec 2019 12:45:49 +0300 Message-ID: <157709434917.12933.4351155074716553976.stgit@pasha-Precision-3630-Tower> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 83.149.199.45 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, peter.maydell@linaro.org, pavel.dovgaluk@ispras.ru, pbonzini@redhat.com, quintela@redhat.com, ciro.santilli@gmail.com, jasowang@redhat.com, crosthwaite.peter@gmail.com, armbru@redhat.com, mreitz@redhat.com, alex.bennee@linaro.org, maria.klimushenkova@ispras.ru, mst@redhat.com, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, dovgaluk@ispras.ru, artem.k.pisarenko@gmail.com, dgilbert@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" GDB remote protocol supports reverse debugging of the targets. It includes 'reverse step' and 'reverse continue' operations. The first one finds the previous step of the execution, and the second one is intended to stop at the last breakpoint that would happen when the program is executed normally. Reverse debugging is possible in the replay mode, when at least one snapshot was created at the record or replay phase. QEMU can use these snapshots for travelling back in time with GDB. Running the execution in replay mode allows using GDB reverse debugging commands: - reverse-stepi (or rsi): Steps one instruction to the past. QEMU loads on of the prior snapshots and proceeds to the desired instruction forward. When that step is reaches, execution stops. - reverse-continue (or rc): Runs execution "backwards". QEMU tries to find breakpoint or watchpoint by loaded prior snapshot and replaying the execution. Then QEMU loads snapshots again and replays to the latest breakpoint. When there are no breakpoints in the examined section of the execution, QEMU finds one more snapshot and tries again. After the first snapshot is processed, execution stops at this snapshot. The set of patches include the following modifications: - gdbstub update for reverse debugging support - functions that automatically perform reverse step and reverse continue operations - hmp/qmp commands for manipulating the replay process - improvement of the snapshotting for saving the execution step in the snapshot parameters The patches are available in the repository: https://github.com/ispras/qemu/tree/rr-191223 --- Pavel Dovgaluk (11): replay: provide an accessor for rr filename qcow2: introduce icount field for snapshots migration: introduce icount field for snapshots qapi: introduce replay.json for record/replay-related stuff replay: introduce info hmp/qmp command replay: introduce breakpoint at the specified step replay: implement replay-seek command replay: flush rr queue before loading the vmstate gdbstub: add reverse step support in replay mode gdbstub: add reverse continue support in replay mode replay: describe reverse debugging in docs/replay.txt MAINTAINERS | 1 accel/tcg/translator.c | 1 block/qapi.c | 18 ++ block/qcow2-snapshot.c | 9 + block/qcow2.h | 3 blockdev.c | 10 + cpus.c | 19 ++- docs/interop/qcow2.txt | 4 + docs/replay.txt | 33 +++++ exec.c | 8 + gdbstub.c | 64 ++++++++- hmp-commands-info.hx | 14 ++ hmp-commands.hx | 53 +++++++ include/block/snapshot.h | 1 include/monitor/hmp.h | 4 + include/sysemu/replay.h | 24 +++ migration/savevm.c | 17 ++ qapi/Makefile.objs | 2 qapi/block-core.json | 8 + qapi/block.json | 3 qapi/misc.json | 18 -- qapi/qapi-schema.json | 1 qapi/replay.json | 121 +++++++++++++++++ replay/Makefile.objs | 1 replay/replay-debugging.c | 325 +++++++++++++++++++++++++++++++++++++++++++++ replay/replay-internal.h | 6 + replay/replay.c | 22 +++ stubs/replay.c | 10 + 28 files changed, 761 insertions(+), 39 deletions(-) create mode 100644 qapi/replay.json create mode 100644 replay/replay-debugging.c -- Pavel Dovgalyuk