From mboxrd@z Thu Jan 1 00:00:00 1970 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 From: Pavel Dovgalyuk 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> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [RFC PATCH v6 12/20] replay: make locking visible outside replay code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, peter.maydell@linaro.org, war2jordan@live.com, boost.lists@gmail.com, 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, pavel.dovgaluk@ispras.ru, thomas.dullien@googlemail.com, pbonzini@redhat.com, alex.bennee@linaro.org From: Alex Benn=C3=A9e 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 Benn=C3=A9e 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; =20 +/* 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 */ =20 /*! 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); } =20 -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); =20 -/* Mutex functions for protecting replay log file */ +/* Mutex functions for protecting replay log file and ensuring + * synchronisation between vCPU and main-loop threads. */ =20 void replay_mutex_init(void); void replay_mutex_destroy(void); -void replay_mutex_lock(void); -void replay_mutex_unlock(void); =20 /*! 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; +}