From patchwork Wed Feb 7 12:05:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 10205051 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 06829602D8 for ; Wed, 7 Feb 2018 12:15:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E0B9628F29 for ; Wed, 7 Feb 2018 12:15:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D528E28F2C; Wed, 7 Feb 2018 12:15:29 +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=-6.9 required=2.0 tests=BAYES_00,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 5734228F29 for ; Wed, 7 Feb 2018 12:15:29 +0000 (UTC) Received: from localhost ([::1]:57044 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOdM-0002CX-2C for patchwork-qemu-devel@patchwork.kernel.org; Wed, 07 Feb 2018 07:15:28 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50318) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOTE-0000ia-Kl for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:05:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ejOTD-0004GT-I0 for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:05:00 -0500 Received: from mail.ispras.ru ([83.149.199.45]:47546) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOTD-0004G5-Am for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:04:59 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 7331854008B; Wed, 7 Feb 2018 15:04:58 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 07 Feb 2018 15:05:00 +0300 Message-ID: <20180207120500.5389.4855.stgit@pasha-VirtualBox> In-Reply-To: <20180207120353.5389.54531.stgit@pasha-VirtualBox> References: <20180207120353.5389.54531.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] [RFC PATCH v6 12/20] replay: make locking visible outside replay code 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, quintela@redhat.com, ciro.santilli@gmail.com, jasowang@redhat.com, mst@redhat.com, zuban32s@gmail.com, maria.klimushenkova@ispras.ru, dovgaluk@ispras.ru, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, pbonzini@redhat.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Alex Bennée The replay_mutex_lock/unlock/locked functions are now going to be used for ensuring lock-step behaviour between the two threads. Make them public API functions and also provide stubs for non-QEMU builds on common paths. Signed-off-by: Alex Bennée Tested-by: Pavel Dovgalyuk --- include/sysemu/replay.h | 14 ++++++++++++++ replay/replay-internal.c | 2 +- replay/replay-internal.h | 5 ++--- stubs/replay.c | 15 +++++++++++++++ 4 files changed, 32 insertions(+), 4 deletions(-) diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h index b86d6bb..9973849 100644 --- a/include/sysemu/replay.h +++ b/include/sysemu/replay.h @@ -47,6 +47,20 @@ extern ReplayMode replay_mode; /* Name of the initial VM snapshot */ extern char *replay_snapshot; +/* Replay locking + * + * The locks are needed to protect the shared structures and log file + * when doing record/replay. They also are the main sync-point between + * the main-loop thread and the vCPU thread. This was a role + * previously filled by the BQL which has been busy trying to reduce + * its impact across the code. This ensures blocks of events stay + * sequential and reproducible. + */ + +void replay_mutex_lock(void); +void replay_mutex_unlock(void); +bool replay_mutex_locked(void); + /* Replay process control functions */ /*! Enables recording or saving event log with specified parameters */ diff --git a/replay/replay-internal.c b/replay/replay-internal.c index 0d7e1d6..7cdefea 100644 --- a/replay/replay-internal.c +++ b/replay/replay-internal.c @@ -181,7 +181,7 @@ void replay_mutex_destroy(void) qemu_mutex_destroy(&lock); } -static bool replay_mutex_locked(void) +bool replay_mutex_locked(void) { return replay_locked; } diff --git a/replay/replay-internal.h b/replay/replay-internal.h index 8e4c701..f5f8e96 100644 --- a/replay/replay-internal.h +++ b/replay/replay-internal.h @@ -100,12 +100,11 @@ int64_t replay_get_qword(void); void replay_get_array(uint8_t *buf, size_t *size); void replay_get_array_alloc(uint8_t **buf, size_t *size); -/* Mutex functions for protecting replay log file */ +/* Mutex functions for protecting replay log file and ensuring + * synchronisation between vCPU and main-loop threads. */ void replay_mutex_init(void); void replay_mutex_destroy(void); -void replay_mutex_lock(void); -void replay_mutex_unlock(void); /*! Checks error status of the file. */ void replay_check_error(void); diff --git a/stubs/replay.c b/stubs/replay.c index 9991ee5..cb050ef 100644 --- a/stubs/replay.c +++ b/stubs/replay.c @@ -73,3 +73,18 @@ uint64_t blkreplay_next_id(void) { return 0; } + +void replay_mutex_lock(void) +{ + abort(); +} + +void replay_mutex_unlock(void) +{ + abort(); +} + +bool replay_mutex_locked(void) +{ + return false; +}