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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 5427DC54E58 for ; Mon, 18 Mar 2024 15:48:57 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rmFEB-0000yY-9P; Mon, 18 Mar 2024 11:48:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rmFE8-0000ks-Vw for qemu-devel@nongnu.org; Mon, 18 Mar 2024 11:48:41 -0400 Received: from mail-oi1-x22f.google.com ([2607:f8b0:4864:20::22f]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rmFDz-000809-Vs for qemu-devel@nongnu.org; Mon, 18 Mar 2024 11:48:40 -0400 Received: by mail-oi1-x22f.google.com with SMTP id 5614622812f47-3c37af44dcbso1713885b6e.3 for ; Mon, 18 Mar 2024 08:48:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1710776908; x=1711381708; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=CiDAmOnmWT4ekrWuB2ITbU/+cCjo/0GhwwVWCJ90GMA=; b=iiVrYLbq7NxMwFBuajV3OePao5hJ9moGchCBpvLCkGQopNut9c+YZgSEfx6AGhgobD h5tCZ7Inh4GLOEpAQZEMzP1fgJpsreTQf/GMdN9cTsSzSYqWPzTqYefpGcqBvi+dUGrV 6c6bVIKXGjrJ8EhqIE898T1iYYlDsOqGZz8XtsMegGFtnuns17QhNErtJAn027MJRMtJ Ey+TKScs04EN1c43YoR/19kCEViAfJI8IPhzHRCsCRp93lIhpRu5Ejg8xMaZ5kypLtG7 xxWcmAmmnZwGOBh32FXUeisDgQmnatw2nmd+16FcuSFOVcovopH6DgMc09wFmy7hMXzJ 01cQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710776908; x=1711381708; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=CiDAmOnmWT4ekrWuB2ITbU/+cCjo/0GhwwVWCJ90GMA=; b=r4gT0pblNs+SRTtcqxl7/FVmwMzr+OokfkyXONjKfqkjz8DEvLyHzibo2220ySC6Er aoxfob/K8EgcSjxbkAkqNGAeH5QOlyQ3lJ3RM0G5VukCSR89z8q46BoSKy5X83QvW7xa 2SIiqX4dbI4uKzWpqLtHNuS2osqDrKs1df5FGndeO8UqfN/KqXDZyRF6jvEKyAY24Ypu k2yI/XZ+wrNJr8GDUQq2eeTYF+JlhOgDMap0eUBsXklRYgDvcfhUO6vofDeA+u8iXe4s Pwtnq2Ox1HZFnBBgR+qv2xsxFSJJ9D38CNVOPKUDGn4Oud+yTUlkKd2tsk/5cVdsMX1B QBww== X-Gm-Message-State: AOJu0YzXzZEqUmLfQ4mkcIA5VbcQMZRcdsrZuuTOuFBagJ5naI69S+w5 ME9YGOYCpbLpIkOtSiLj7LIhuJHt1cjMkj75/cjqSooZMuu8ektKIWFI50cTDqY= X-Google-Smtp-Source: AGHT+IGeaApjV32xwbtP1EsJ30sONIG0xua+WZd5or9j2JP5SH9MQ9HdVJAxEy4J9htvqYnfLbICpA== X-Received: by 2002:a05:6871:7981:b0:220:e608:89c with SMTP id pb1-20020a056871798100b00220e608089cmr14584816oac.28.1710776908370; Mon, 18 Mar 2024 08:48:28 -0700 (PDT) Received: from wheely.local0.net ([118.208.155.46]) by smtp.gmail.com with ESMTPSA id v22-20020a634816000000b005dc26144d96sm7332108pga.75.2024.03.18.08.48.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Mar 2024 08:48:28 -0700 (PDT) From: Nicholas Piggin To: qemu-devel@nongnu.org Cc: Nicholas Piggin , Pavel Dovgalyuk , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Richard Henderson , =?UTF-8?q?Alex=20Benn=C3=A9e?= , Paolo Bonzini , John Snow , Cleber Rosa , Wainer dos Santos Moschetta , Beraldo Leal , Michael Tokarev Subject: [PATCH v5 20/24] replay: simple auto-snapshot mode for record Date: Tue, 19 Mar 2024 01:46:17 +1000 Message-ID: <20240318154621.2361161-21-npiggin@gmail.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20240318154621.2361161-1-npiggin@gmail.com> References: <20240318154621.2361161-1-npiggin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2607:f8b0:4864:20::22f; envelope-from=npiggin@gmail.com; helo=mail-oi1-x22f.google.com 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, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org record makes an initial snapshot when the machine is created, to enable reverse-debugging. Often the issue being debugged appears near the end of the trace, so it is important for performance to keep snapshots close to the end. This implements a periodic snapshot mode that keeps a rolling set of recent snapshots. This could be done by the debugger or other program that talks QMP, but for setting up simple scenarios and tests, this is more convenient. Signed-off-by: Nicholas Piggin --- docs/system/replay.rst | 5 ++++ include/sysemu/replay.h | 11 ++++++++ replay/replay-snapshot.c | 57 ++++++++++++++++++++++++++++++++++++++++ replay/replay.c | 27 +++++++++++++++++-- system/vl.c | 9 +++++++ qemu-options.hx | 9 +++++-- 6 files changed, 114 insertions(+), 4 deletions(-) diff --git a/docs/system/replay.rst b/docs/system/replay.rst index ca7c17c63d..1ae8614475 100644 --- a/docs/system/replay.rst +++ b/docs/system/replay.rst @@ -156,6 +156,11 @@ for storing VM snapshots. Here is the example of the command line for this: ``empty.qcow2`` drive does not connected to any virtual block device and used for VM snapshots only. +``rrsnapmode`` can be used to select just an initial snapshot or periodic +snapshots, with ``rrsnapcount`` specifying the number of periodic snapshots +to maintain, and ``rrsnaptime`` the amount of run time in seconds between +periodic snapshots. + .. _network-label: Network devices diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h index 8102fa54f0..92fa82842b 100644 --- a/include/sysemu/replay.h +++ b/include/sysemu/replay.h @@ -48,6 +48,17 @@ typedef enum ReplayCheckpoint ReplayCheckpoint; typedef struct ReplayNetState ReplayNetState; +enum ReplaySnapshotMode { + REPLAY_SNAPSHOT_MODE_INITIAL, + REPLAY_SNAPSHOT_MODE_PERIODIC, +}; +typedef enum ReplaySnapshotMode ReplaySnapshotMode; + +extern ReplaySnapshotMode replay_snapshot_mode; + +extern uint64_t replay_snapshot_periodic_delay; +extern int replay_snapshot_periodic_nr_keep; + /* Name of the initial VM snapshot */ extern char *replay_snapshot; diff --git a/replay/replay-snapshot.c b/replay/replay-snapshot.c index ccb4d89dda..762555feaa 100644 --- a/replay/replay-snapshot.c +++ b/replay/replay-snapshot.c @@ -70,6 +70,53 @@ void replay_vmstate_register(void) vmstate_register(NULL, 0, &vmstate_replay, &replay_state); } +static QEMUTimer *replay_snapshot_timer; +static int replay_snapshot_count; + +static void replay_snapshot_timer_cb(void *opaque) +{ + Error *err = NULL; + char *name; + + if (!replay_can_snapshot()) { + /* Try again soon */ + timer_mod(replay_snapshot_timer, + qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + + replay_snapshot_periodic_delay / 10); + return; + } + + name = g_strdup_printf("%s-%d", replay_snapshot, replay_snapshot_count); + if (!save_snapshot(name, + true, NULL, false, NULL, &err)) { + error_report_err(err); + error_report("Could not create periodic snapshot " + "for icount record, disabling"); + g_free(name); + return; + } + g_free(name); + replay_snapshot_count++; + + if (replay_snapshot_periodic_nr_keep >= 1 && + replay_snapshot_count > replay_snapshot_periodic_nr_keep) { + int del_nr; + + del_nr = replay_snapshot_count - replay_snapshot_periodic_nr_keep - 1; + name = g_strdup_printf("%s-%d", replay_snapshot, del_nr); + if (!delete_snapshot(name, false, NULL, &err)) { + error_report_err(err); + error_report("Could not delete periodic snapshot " + "for icount record"); + } + g_free(name); + } + + timer_mod(replay_snapshot_timer, + qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + + replay_snapshot_periodic_delay); +} + void replay_vmstate_init(void) { Error *err = NULL; @@ -82,6 +129,16 @@ void replay_vmstate_init(void) error_report("Could not create snapshot for icount record"); exit(1); } + + if (replay_snapshot_mode == REPLAY_SNAPSHOT_MODE_PERIODIC) { + replay_snapshot_timer = timer_new_ms(QEMU_CLOCK_REALTIME, + replay_snapshot_timer_cb, + NULL); + timer_mod(replay_snapshot_timer, + qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + + replay_snapshot_periodic_delay); + } + } else if (replay_mode == REPLAY_MODE_PLAY) { if (!load_snapshot(replay_snapshot, NULL, false, NULL, &err)) { error_report_err(err); diff --git a/replay/replay.c b/replay/replay.c index 895fa6b67a..c916e71d30 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -29,6 +29,10 @@ ReplayMode replay_mode = REPLAY_MODE_NONE; char *replay_snapshot; +ReplaySnapshotMode replay_snapshot_mode; +uint64_t replay_snapshot_periodic_delay; +int replay_snapshot_periodic_nr_keep; + /* Name of replay file */ static char *replay_filename; ReplayState replay_state; @@ -424,6 +428,27 @@ void replay_configure(QemuOpts *opts) } replay_snapshot = g_strdup(qemu_opt_get(opts, "rrsnapshot")); + if (replay_snapshot && mode == REPLAY_MODE_RECORD) { + const char *snapmode; + + snapmode = qemu_opt_get(opts, "rrsnapmode"); + if (!snapmode || !strcmp(snapmode, "initial")) { + replay_snapshot_mode = REPLAY_SNAPSHOT_MODE_INITIAL; + } else if (!strcmp(snapmode, "periodic")) { + replay_snapshot_mode = REPLAY_SNAPSHOT_MODE_PERIODIC; + } else { + error_report("Invalid rrsnapmode option: %s", snapmode); + exit(1); + } + + /* Default 10 host seconds of machine runtime per snapshot. */ + replay_snapshot_periodic_delay = + qemu_opt_get_number(opts, "rrsnaptime", 10) * 1000; + + /* Default 2, to cover at least the last 10 host seconds of runtime. */ + replay_snapshot_periodic_nr_keep = + qemu_opt_get_number(opts, "rrsnapcount", 2); + } replay_vmstate_register(); replay_enable(fname, mode); @@ -446,8 +471,6 @@ void replay_start(void) exit(1); } - /* Timer for snapshotting will be set up here. */ - replay_enable_events(); } diff --git a/system/vl.c b/system/vl.c index 70f4cece7f..8070cee6da 100644 --- a/system/vl.c +++ b/system/vl.c @@ -447,6 +447,15 @@ static QemuOptsList qemu_icount_opts = { }, { .name = "rrsnapshot", .type = QEMU_OPT_STRING, + }, { + .name = "rrsnapmode", + .type = QEMU_OPT_STRING, + }, { + .name = "rrsnaptime", + .type = QEMU_OPT_NUMBER, + }, { + .name = "rrsnapcount", + .type = QEMU_OPT_NUMBER, }, { /* end of list */ } }, diff --git a/qemu-options.hx b/qemu-options.hx index 7fd1713fa8..51f2498f12 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4665,13 +4665,13 @@ SRST ERST DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ - "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=[,rrsnapshot=]]\n" \ + "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=[,rrsnapshot=][,rrsnapmode=initial|periodic][,rrsnaptime=secs][,rrsnapcount=N]\n" \ " enable virtual instruction counter with 2^N clock ticks per\n" \ " instruction, enable aligning the host and virtual clocks\n" \ " or disable real time cpu sleeping, and optionally enable\n" \ " record-and-replay mode\n", QEMU_ARCH_ALL) SRST -``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]`` +``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot][,rrsnapmode=initial|periodic][,rrsnaptime=secs][,rrsnapcount=N]]`` Enable virtual instruction counter. The virtual cpu will execute one instruction every 2^N ns of virtual time. If ``auto`` is specified then the virtual cpu speed will be automatically adjusted to keep @@ -4713,6 +4713,11 @@ SRST name. In record mode, a new VM snapshot with the given name is created at the start of execution recording. In replay mode this option specifies the snapshot name used to load the initial VM state. + ``rrsnapmode=periodic`` will additionally cause a periodic snapshot to + be created after ``rrsnaptime=secs`` seconds of real runtime. The last + ``rrsnapcount=N`` periodic snapshots (not including the initial) will + be kept (0 for infinite). Periodic snapshots are useful to speed + reverse debugging operations near the end of the recorded trace. ERST DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \ -- 2.42.0