From patchwork Wed Apr 25 12:45:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 10363027 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 BD9D26032C for ; Wed, 25 Apr 2018 12:51:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ACF8128D62 for ; Wed, 25 Apr 2018 12:51:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9F1D328D7F; Wed, 25 Apr 2018 12:51:27 +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 1990928D62 for ; Wed, 25 Apr 2018 12:51:27 +0000 (UTC) Received: from localhost ([::1]:36598 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fBJtO-0004wX-8f for patchwork-qemu-devel@patchwork.kernel.org; Wed, 25 Apr 2018 08:51:26 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56870) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fBJoK-0001G3-Va for qemu-devel@nongnu.org; Wed, 25 Apr 2018 08:46:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fBJoH-0002vZ-1a for qemu-devel@nongnu.org; Wed, 25 Apr 2018 08:46:13 -0400 Received: from mail.ispras.ru ([83.149.199.45]:42330) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fBJoG-0002u5-Pa for qemu-devel@nongnu.org; Wed, 25 Apr 2018 08:46:08 -0400 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id C10EC5400A9; Wed, 25 Apr 2018 15:46:07 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 25 Apr 2018 15:45:57 +0300 Message-ID: <20180425124557.17182.76659.stgit@pasha-VirtualBox> In-Reply-To: <20180425124533.17182.53165.stgit@pasha-VirtualBox> References: <20180425124533.17182.53165.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 04/17] 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 bd9a19a..1ceefbc 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 */ @@ -407,6 +408,13 @@ void bdrv_drain_all_begin(void) BdrvNextIterator it; GSList *aio_ctxs = NULL, *ctx; + /* bdrv queue is managed by record/replay, + waiting for finishing the I/O requests may + be infinite */ + if (replay_events_enabled()) { + return; + } + /* BDRV_POLL_WHILE() for a node can only be called from its own I/O thread * or the main loop AioContext. We potentially use BDRV_POLL_WHILE() on * nodes in several different AioContexts, so make sure we're in the main @@ -458,6 +466,13 @@ void bdrv_drain_all_end(void) BlockDriverState *bs; BdrvNextIterator it; + /* bdrv queue is managed by record/replay, + waiting for finishing the I/O requests may + be endless */ + if (replay_events_enabled()) { + return; + } + for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { AioContext *aio_context = bdrv_get_aio_context(bs); @@ -1832,6 +1847,13 @@ 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 38eba8b..140cc4f 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; @@ -2059,7 +2058,6 @@ int vm_prepare_start(void) qapi_event_send_stop(&error_abort); res = -1; } else { - replay_enable_events(); cpu_enable_ticks(); runstate_set(RUN_STATE_RUNNING); vm_state_notify(1, RUN_STATE_RUNNING);