From patchwork Wed Jul 25 12:13:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 10543929 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 E1F68157A for ; Wed, 25 Jul 2018 12:18:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CF92E29D57 for ; Wed, 25 Jul 2018 12:18:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C2E9429D5C; Wed, 25 Jul 2018 12:18:07 +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 6358029D5A for ; Wed, 25 Jul 2018 12:18:07 +0000 (UTC) Received: from localhost ([::1]:49163 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fiIk2-0004CL-Gx for patchwork-qemu-devel@patchwork.kernel.org; Wed, 25 Jul 2018 08:18:06 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38902) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fiIfh-0000mz-Ev for qemu-devel@nongnu.org; Wed, 25 Jul 2018 08:13:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fiIfe-0002Hd-E2 for qemu-devel@nongnu.org; Wed, 25 Jul 2018 08:13:37 -0400 Received: from mail.ispras.ru ([83.149.199.45]:36392) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fiIfe-0002H4-5I for qemu-devel@nongnu.org; Wed, 25 Jul 2018 08:13:34 -0400 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 40CE054006B; Wed, 25 Jul 2018 15:13:33 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 25 Jul 2018 15:13:35 +0300 Message-ID: <20180725121335.12867.34703.stgit@pasha-VirtualBox> In-Reply-To: <20180725121311.12867.21729.stgit@pasha-VirtualBox> References: <20180725121311.12867.21729.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] [PATCH v5 04/24] 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 b5844b7..9b98b1f 100644 --- a/cpus.c +++ b/cpus.c @@ -1016,7 +1016,6 @@ static int do_vm_stop(RunState state, bool send_stop) } bdrv_drain_all(); - replay_disable_events(); ret = bdrv_flush_all(); return ret; @@ -2067,7 +2066,6 @@ 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);