From patchwork Wed Sep 12 08:18:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 10597025 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0B3A314DB for ; Wed, 12 Sep 2018 08:22:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EECAD29949 for ; Wed, 12 Sep 2018 08:22:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E2D0C29968; Wed, 12 Sep 2018 08:22:31 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 8B71529949 for ; Wed, 12 Sep 2018 08:22:31 +0000 (UTC) Received: from localhost ([::1]:35051 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g00Pu-0003kL-MP for patchwork-qemu-devel@patchwork.kernel.org; Wed, 12 Sep 2018 04:22:30 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47063) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g00Lq-0000P9-FI for qemu-devel@nongnu.org; Wed, 12 Sep 2018 04:18:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g00Ll-000883-G3 for qemu-devel@nongnu.org; Wed, 12 Sep 2018 04:18:18 -0400 Received: from mail.ispras.ru ([83.149.199.45]:55690) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g00Ll-00087r-7n for qemu-devel@nongnu.org; Wed, 12 Sep 2018 04:18:13 -0400 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 4783554008B; Wed, 12 Sep 2018 11:18:12 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 12 Sep 2018 11:18:11 +0300 Message-ID: <20180912081811.3228.51895.stgit@pasha-VirtualBox> In-Reply-To: <20180912081747.3228.21861.stgit@pasha-VirtualBox> References: <20180912081747.3228.21861.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 X-Received-From: 83.149.199.45 Subject: [Qemu-devel] [PATCH v6 04/25] replay: don't drain/flush bdrv queue while RR is working 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, pbonzini@redhat.com, quintela@redhat.com, ciro.santilli@gmail.com, jasowang@redhat.com, crosthwaite.peter@gmail.com, zuban32s@gmail.com, armbru@redhat.com, maria.klimushenkova@ispras.ru, mst@redhat.com, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, dovgaluk@ispras.ru, mreitz@redhat.com, alex.bennee@linaro.org, dgilbert@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP In record/replay mode bdrv queue is controlled by replay mechanism. It does not allow saving or loading the snapshots when bdrv queue is not empty. Stopping the VM is not blocked by nonempty queue, but flushing the queue is still impossible there, because it may cause deadlocks in replay mode. This patch disables bdrv_drain_all and bdrv_flush_all in record/replay mode. Signed-off-by: Pavel Dovgalyuk --- block/io.c | 22 ++++++++++++++++++++++ cpus.c | 2 -- 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index 7100344..4d7a6e4 100644 --- a/block/io.c +++ b/block/io.c @@ -32,6 +32,7 @@ #include "qemu/cutils.h" #include "qapi/error.h" #include "qemu/error-report.h" +#include "sysemu/replay.h" #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ @@ -533,6 +534,13 @@ void bdrv_drain_all_begin(void) return; } + /* bdrv queue is managed by record/replay, + waiting for finishing the I/O requests may + be infinite */ + if (replay_events_enabled()) { + return; + } + /* AIO_WAIT_WHILE() with a NULL context can only be called from the main * loop AioContext, so make sure we're in the main context. */ assert(qemu_get_current_aio_context() == qemu_get_aio_context()); @@ -561,6 +569,13 @@ void bdrv_drain_all_end(void) { BlockDriverState *bs = NULL; + /* bdrv queue is managed by record/replay, + waiting for finishing the I/O requests may + be endless */ + if (replay_events_enabled()) { + return; + } + while ((bs = bdrv_next_all_states(bs))) { AioContext *aio_context = bdrv_get_aio_context(bs); @@ -1993,6 +2008,13 @@ int bdrv_flush_all(void) BlockDriverState *bs = NULL; int result = 0; + /* bdrv queue is managed by record/replay, + creating new flush request for stopping + the VM may break the determinism */ + if (replay_events_enabled()) { + return result; + } + for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { AioContext *aio_context = bdrv_get_aio_context(bs); int ret; diff --git a/cpus.c b/cpus.c index f257a6e..0ce5640 100644 --- a/cpus.c +++ b/cpus.c @@ -1058,7 +1058,6 @@ static int do_vm_stop(RunState state, bool send_stop) } bdrv_drain_all(); - replay_disable_events(); ret = bdrv_flush_all(); return ret; @@ -2115,7 +2114,6 @@ int vm_prepare_start(void) /* We are sending this now, but the CPUs will be resumed shortly later */ qapi_event_send_resume(&error_abort); - replay_enable_events(); cpu_enable_ticks(); runstate_set(RUN_STATE_RUNNING); vm_state_notify(1, RUN_STATE_RUNNING);