From patchwork Tue Aug 13 05:06:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 13761317 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 CBB2EC52D7B for ; Tue, 13 Aug 2024 05:08:44 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sdjkb-0000kS-NQ; Tue, 13 Aug 2024 01:07:17 -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 1sdjkY-0000cH-CE for qemu-devel@nongnu.org; Tue, 13 Aug 2024 01:07:14 -0400 Received: from mail-oa1-x31.google.com ([2001:4860:4864:20::31]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sdjkW-0007o1-Nh for qemu-devel@nongnu.org; Tue, 13 Aug 2024 01:07:14 -0400 Received: by mail-oa1-x31.google.com with SMTP id 586e51a60fabf-260e12aac26so3089422fac.0 for ; Mon, 12 Aug 2024 22:07:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1723525631; x=1724130431; 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=uk+FHi4sItVUZ9MtIdmqXg+AZpvHhtDmQ3HZJea9zck=; b=LSQPH3fr1zV6eiQacLUosvMhywOp99jXRMHNZ11IgBWYNAfF65wLwJsGa1Y5cmITaM 1bspkSspNQ4E2bcVovFptFTR0KpsKQafQ7RoxdDJVYnIZXye1w49JBZP7/QpBTmvxZTn xz37PeW13VBAJ2/+15RD8yCbzeCraYFlAUpQmSxw9zUoVOKz6AI8FzsdBGi2gO8Im5es xPCrR+MKALdzMYpEk67qmNG0/Ivx0rQm5KPapFDqO0udPswwkz3BYq2njdPheYYFAg2L n2G7vUED5JKGVOpdsI6SBceOOemlVIYp8mmCU7WNqMv8alHZHIHNliqhB5e94xkkmOrk o+WQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723525631; x=1724130431; 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=uk+FHi4sItVUZ9MtIdmqXg+AZpvHhtDmQ3HZJea9zck=; b=Y+U+SHBX5waOvYL5REcpqHy4W2HFHQqfjGfuXo8Czn6KgquRVR10R6OXZ6bN0Kp0Jr TQ2ZL2gmB3BGDa7WVlTcVgsYbsstAb1cm6TXxXOHPn0K/KCSyPWKzhvR0B1F9ijV0JHN XEtWo3rvw73CrBQESo1YkLRlRuXmh+LEmqI6R4hMHzpB07IV/sA7AfVjBSEeflnM5EYW NhK5xr380lF7EeLwcHPAlYimWELvMNSCjlWABjkeTHd2bMuPNgYpiYNj4H4ptZkCQFBV /FUpB+uxJb2kZqdb0mPoQRUI4pA1iwz2WW2iBRjQMXvhyZoTYKd533jrzSVIQSHWG5Ak EnqQ== X-Gm-Message-State: AOJu0YwJQWY7hgqEnOlleC2Z5R8khPQbHy9qLrivEa16kd1xQYZMGCos 0VzSl4ah8PWnNHM01ZvXpKfqno3AaSIwlLmuUIksoaKaDOhJIhErQA/gZb+F X-Google-Smtp-Source: AGHT+IHZlSuxt1INtJlaCPp5KVc5JqJeMhWHEal97fGaZRrH184GImoiy6qLih1ryQwBznQsNSKJXw== X-Received: by 2002:a05:6870:65a0:b0:254:8666:cded with SMTP id 586e51a60fabf-26fcb65ff11mr2877835fac.11.1723525631083; Mon, 12 Aug 2024 22:07:11 -0700 (PDT) Received: from wheely.local0.net ([1.145.66.74]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-710e5874ddcsm4846449b3a.28.2024.08.12.22.07.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Aug 2024 22:07:10 -0700 (PDT) From: Nicholas Piggin To: qemu-devel@nongnu.org Cc: Nicholas Piggin , Pavel Dovgalyuk , =?utf-8?q?Philippe_Mathieu-Dau?= =?utf-8?q?d=C3=A9?= , Richard Henderson , =?utf-8?q?Alex_Benn=C3=A9?= =?utf-8?q?e?= , Paolo Bonzini , John Snow , Cleber Rosa , Wainer dos Santos Moschetta , Beraldo Leal , Michael Tokarev Subject: [PATCH v6 04/10] replay: allow runstate shutdown->running when replaying trace Date: Tue, 13 Aug 2024 15:06:31 +1000 Message-ID: <20240813050638.446172-5-npiggin@gmail.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240813050638.446172-1-npiggin@gmail.com> References: <20240813050638.446172-1-npiggin@gmail.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2001:4860:4864:20::31; envelope-from=npiggin@gmail.com; helo=mail-oa1-x31.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 When replaying a trace, it is possible to go from shutdown to running with a reverse-debugging step. This can be useful if the problem being debugged triggers a reset or shutdown. This can be tested by making a recording of a machine that shuts down, then using -action shutdown=pause when replaying it. Continuing to the end of the trace then reverse-stepping in gdb crashes due to invalid runstate transition. Just permitting the transition seems to be all that's necessary for reverse-debugging to work well in such a state. Reviewed-by: Alex Bennée Reviewed-by: Pavel Dovgalyuk Signed-off-by: Nicholas Piggin --- include/sysemu/runstate.h | 1 + replay/replay.c | 2 ++ system/runstate.c | 31 ++++++++++++++++++++++++++++--- 3 files changed, 31 insertions(+), 3 deletions(-) diff --git a/include/sysemu/runstate.h b/include/sysemu/runstate.h index e210a37abf..11c7ff3ffb 100644 --- a/include/sysemu/runstate.h +++ b/include/sysemu/runstate.h @@ -9,6 +9,7 @@ void runstate_set(RunState new_state); RunState runstate_get(void); bool runstate_is_running(void); bool runstate_needs_reset(void); +void runstate_replay_enable(void); typedef void VMChangeStateHandler(void *opaque, bool running, RunState state); diff --git a/replay/replay.c b/replay/replay.c index a2c576c16e..b8564a4813 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -385,6 +385,8 @@ static void replay_enable(const char *fname, int mode) replay_fetch_data_kind(); } + runstate_replay_enable(); + replay_init_events(); } diff --git a/system/runstate.c b/system/runstate.c index c833316f6d..a0e2a5fd22 100644 --- a/system/runstate.c +++ b/system/runstate.c @@ -181,6 +181,12 @@ static const RunStateTransition runstate_transitions_def[] = { { RUN_STATE__MAX, RUN_STATE__MAX }, }; +static const RunStateTransition replay_play_runstate_transitions_def[] = { + { RUN_STATE_SHUTDOWN, RUN_STATE_RUNNING}, + + { RUN_STATE__MAX, RUN_STATE__MAX }, +}; + static bool runstate_valid_transitions[RUN_STATE__MAX][RUN_STATE__MAX]; bool runstate_check(RunState state) @@ -188,14 +194,33 @@ bool runstate_check(RunState state) return current_run_state == state; } -static void runstate_init(void) +static void transitions_set_valid(const RunStateTransition *rst) { const RunStateTransition *p; - memset(&runstate_valid_transitions, 0, sizeof(runstate_valid_transitions)); - for (p = &runstate_transitions_def[0]; p->from != RUN_STATE__MAX; p++) { + for (p = rst; p->from != RUN_STATE__MAX; p++) { runstate_valid_transitions[p->from][p->to] = true; } +} + +void runstate_replay_enable(void) +{ + assert(replay_mode != REPLAY_MODE_NONE); + + if (replay_mode == REPLAY_MODE_PLAY) { + /* + * When reverse-debugging, it is possible to move state from + * shutdown to running. + */ + transitions_set_valid(&replay_play_runstate_transitions_def[0]); + } +} + +static void runstate_init(void) +{ + memset(&runstate_valid_transitions, 0, sizeof(runstate_valid_transitions)); + + transitions_set_valid(&runstate_transitions_def[0]); qemu_mutex_init(&vmstop_lock); }