From patchwork Mon Mar 18 15:46:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 13595472 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 4F589C54E5D for ; Mon, 18 Mar 2024 15:47:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rmFCe-0002ln-Kz; Mon, 18 Mar 2024 11:47:08 -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 1rmFCW-0002j6-JP for qemu-devel@nongnu.org; Mon, 18 Mar 2024 11:47:00 -0400 Received: from mail-pg1-x530.google.com ([2607:f8b0:4864:20::530]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rmFCT-0007qp-DP for qemu-devel@nongnu.org; Mon, 18 Mar 2024 11:47:00 -0400 Received: by mail-pg1-x530.google.com with SMTP id 41be03b00d2f7-5cf2d73a183so3725403a12.1 for ; Mon, 18 Mar 2024 08:46:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1710776816; x=1711381616; 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=SaaO9SZsKEZz6NFFljqKDw7YBSQBKN32a+oOPm6wNWc=; b=VQ8JuSZorzEpV1lWWLO3T/j1tttnkMl5OGdNZnkK0HYmMD05n0U3YH+OYcwCj3isya BL1Z4HZSe4pDKYK7KOj72otbgkTEpWGZjoDnNsVAiZ7LZIdm3f6XzVY2sGMI0vWarW6T lJ5iXFLoHdvE8U5bOlwAfaxEpcikgQTP7BRa7rb7fPzWnCf01BhsWngds9yon056r3jA MY2cNCxzP4A1QZhAXAVxCqtfsmTYhXxvrZGZzraN4dDwSz0orv5sd+WXgoGWWoTx1adz QSUniuh/h85diuteuifFJf9toF4zSxNvDgFGAgx4kTln76p75uzkQJbXBAQMug2vxKvi +GUQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710776816; x=1711381616; 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=SaaO9SZsKEZz6NFFljqKDw7YBSQBKN32a+oOPm6wNWc=; b=YlwFuVEJxLVRGU+AALyd/FTQXReg3Fd9LyGoCwlFnu3Vp7EssnkcqWIUzj+rMv1/EA aCgMHWQdcT2BhJEwLbXjhzk425IFsRJlsQ4MnzkM/dfTRCxByda6i6ibJCSOZ3o4vWco 2d1a3YV9DA5bw5uOeFJawESvcqEAz5g+NBufstRYdxcTjjlb03EuNDUKVdt/tCE8mCSa pcf3eqrGKskATX/gPnPdKqBk8135bIWA/9a6VRNH2/boAtHVQvJbffeQ/rv6UHi7kboV 02k542GcM0koc58PtV5+kveu6PxNvEBXlpsPh8SQNrBBz5JXjcKokVGSVvEPHCurSXq/ /Vdg== X-Gm-Message-State: AOJu0Yw6CYqChtPveg8z6dCZJ8SpYNRZjw0U6MivY4WfakydC6y60KEz kCQzPf7dQhNr1obytXpX1l+HqMxhmRVUZY5ckYiaJA0djj0pZuc4flNd1Nk6w8w= X-Google-Smtp-Source: AGHT+IHSOTr/2u6EkLz5/ck5gYpngRGlREmPs99jsA/1P1jPYsWVpLVuF8CDdT9H06jNHjpZlRjxiQ== X-Received: by 2002:a17:90b:34c:b0:29e:89b:9446 with SMTP id fh12-20020a17090b034c00b0029e089b9446mr18621pjb.1.1710776815695; Mon, 18 Mar 2024 08:46:55 -0700 (PDT) Received: from wheely.local0.net ([118.208.155.46]) by smtp.gmail.com with ESMTPSA id v22-20020a634816000000b005dc26144d96sm7332108pga.75.2024.03.18.08.46.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Mar 2024 08:46:55 -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 v5 04/24] replay: allow runstate shutdown->running when replaying trace Date: Tue, 19 Mar 2024 01:46:01 +1000 Message-ID: <20240318154621.2361161-5-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 Received-SPF: pass client-ip=2607:f8b0:4864:20::530; envelope-from=npiggin@gmail.com; helo=mail-pg1-x530.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 0117d243c4..fe25eed3c0 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 d6ab860eca..8f9ee034de 100644 --- a/system/runstate.c +++ b/system/runstate.c @@ -182,6 +182,12 @@ 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) @@ -189,14 +195,33 @@ 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); }