From patchwork Wed Jul 25 12:13:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 10543921 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3472C157A for ; Wed, 25 Jul 2018 12:14:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2046C28B62 for ; Wed, 25 Jul 2018 12:14:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1367328D64; Wed, 25 Jul 2018 12:14:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5DFC828B62 for ; Wed, 25 Jul 2018 12:14:47 +0000 (UTC) Received: from localhost ([::1]:49143 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fiIgn-0001eN-VZ for patchwork-qemu-devel@patchwork.kernel.org; Wed, 25 Jul 2018 08:14:46 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38843) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fiIfN-0000bA-Nh for qemu-devel@nongnu.org; Wed, 25 Jul 2018 08:13:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fiIfK-0001kZ-Lq for qemu-devel@nongnu.org; Wed, 25 Jul 2018 08:13:17 -0400 Received: from mail.ispras.ru ([83.149.199.45]:36314) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fiIfK-0001fI-8a for qemu-devel@nongnu.org; Wed, 25 Jul 2018 08:13:14 -0400 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 6F52A54006B; Wed, 25 Jul 2018 15:13:10 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 25 Jul 2018 15:13:12 +0300 Message-ID: <20180725121311.12867.21729.stgit@pasha-VirtualBox> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 83.149.199.45 Subject: [Qemu-devel] [PATCH v5 00/24] Fixing record/replay and adding reverse debugging X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, war2jordan@live.com, pavel.dovgaluk@ispras.ru, pbonzini@redhat.com, quintela@redhat.com, ciro.santilli@gmail.com, jasowang@redhat.com, crosthwaite.peter@gmail.com, zuban32s@gmail.com, armbru@redhat.com, maria.klimushenkova@ispras.ru, mst@redhat.com, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, dovgaluk@ispras.ru, mreitz@redhat.com, alex.bennee@linaro.org, dgilbert@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP 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: - fixes of record/replay caused by the QEMU core changes - 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 - other record/replay fixes The patches are available in the repository: https://github.com/ispras/qemu/tree/rr-180725 v5 changes: - multiple fixes of record/replay bugs appeared after QEMU core update - changed reverse debugging to 'since 3.1' v4 changes: - changed 'since 2.13' to 'since 3.0' in json (as suggested by Eric Blake) v3 changes: - Fixed PS/2 bug with save/load vm, which caused failures of the replay. - Rebased to the new code base. - Minor fixes. v2 changes: - documented reverse debugging - fixed start vmstate loading in record mode - documented qcow2 changes (as suggested by Eric Blake) - made icount SnapshotInfo field optional (as suggested by Eric Blake) - renamed qmp commands (as suggested by Eric Blake) - minor changes --- Pavel Dovgalyuk (24): block: implement bdrv_snapshot_goto for blkreplay replay: disable default snapshot for record/replay replay: update docs for record/replay with block devices replay: don't drain/flush bdrv queue while RR is working replay: finish record/replay before closing the disks qcow2: introduce icount field for snapshots migration: introduce icount field for snapshots replay: introduce info hmp/qmp command replay: introduce breakpoint at the specified step replay: implement replay-seek command to proceed to the desired step replay: flush events when exiting timer: remove replay clock probe in deadline calculation replay: refine replay-time module translator: fix breakpoint processing 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 replay: allow loading any snapshots before recording ps2: prevent changing irq state on save and load replay: wake up vCPU when replaying replay: replay BH for IDE trim operation replay: add BH oneshot event for block layer slirp: fix ipv6 timers accel/tcg/translator.c | 9 + block/blkreplay.c | 8 + block/block-backend.c | 3 block/io.c | 22 +++ block/qapi.c | 17 ++- block/qcow2-snapshot.c | 9 + block/qcow2.h | 2 blockdev.c | 10 ++ cpus.c | 50 +++++--- docs/interop/qcow2.txt | 4 + docs/replay.txt | 45 +++++++ exec.c | 6 + gdbstub.c | 50 +++++++- hmp-commands-info.hx | 14 ++ hmp-commands.hx | 30 +++++ hmp.h | 3 hw/ide/core.c | 3 hw/input/ps2.c | 8 + include/block/snapshot.h | 1 include/sysemu/replay.h | 24 ++++ migration/savevm.c | 15 +- qapi/block-core.json | 5 + qapi/block.json | 3 qapi/misc.json | 68 +++++++++++ replay/Makefile.objs | 3 replay/replay-debugging.c | 287 +++++++++++++++++++++++++++++++++++++++++++++ replay/replay-events.c | 30 +++-- replay/replay-internal.h | 11 +- replay/replay-snapshot.c | 17 ++- replay/replay-time.c | 27 ++-- replay/replay.c | 36 +++++- slirp/ip6_icmp.c | 6 - stubs/replay.c | 16 +++ util/qemu-timer.c | 11 -- vl.c | 18 ++- 35 files changed, 772 insertions(+), 99 deletions(-) create mode 100644 replay/replay-debugging.c