From patchwork Wed Oct 10 13:33:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 10634563 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 5F072679F for ; Wed, 10 Oct 2018 13:35:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3EFD429E92 for ; Wed, 10 Oct 2018 13:35:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3BEE42A090; Wed, 10 Oct 2018 13:35:55 +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 CF15B2A0AE for ; Wed, 10 Oct 2018 13:35:54 +0000 (UTC) Received: from localhost ([::1]:57318 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAEeY-0005Hx-5M for patchwork-qemu-devel@patchwork.kernel.org; Wed, 10 Oct 2018 09:35:54 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33728) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAEZZ-0001ek-GH for qemu-devel@nongnu.org; Wed, 10 Oct 2018 09:30:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAEZY-0002O0-JF for qemu-devel@nongnu.org; Wed, 10 Oct 2018 09:30:45 -0400 Received: from mail.ispras.ru ([83.149.199.45]:43950) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAEZY-0002Nf-AE for qemu-devel@nongnu.org; Wed, 10 Oct 2018 09:30:44 -0400 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 69DB554008A; Wed, 10 Oct 2018 16:30:43 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 10 Oct 2018 16:33:57 +0300 Message-ID: <20181010133357.24538.19180.stgit@pasha-VirtualBox> In-Reply-To: <20181010133333.24538.53169.stgit@pasha-VirtualBox> References: <20181010133333.24538.53169.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 v7 04/19] 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: peter.maydell@linaro.org, war2jordan@live.com, pavel.dovgaluk@ispras.ru, mst@redhat.com, jasowang@redhat.com, zuban32s@gmail.com, kraxel@redhat.com, thomas.dullien@googlemail.com, artem.k.pisarenko@gmail.com, quintela@redhat.com, ciro.santilli@gmail.com, armbru@redhat.com, dovgaluk@ispras.ru, dgilbert@redhat.com, boost.lists@gmail.com, alex.bennee@linaro.org, rth@twiddle.net, kwolf@redhat.com, crosthwaite.peter@gmail.com, mreitz@redhat.com, maria.klimushenkova@ispras.ru, pbonzini@redhat.com 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 bd9d688..96fb245 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 */ @@ -538,6 +539,13 @@ 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()); @@ -566,6 +574,13 @@ 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); @@ -1997,6 +2012,13 @@ 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 1c741bc..d60ddf1 100644 --- a/cpus.c +++ b/cpus.c @@ -1078,7 +1078,6 @@ static int do_vm_stop(RunState state, bool send_stop) } bdrv_drain_all(); - replay_disable_events(); ret = bdrv_flush_all(); return ret; @@ -2135,7 +2134,6 @@ int vm_prepare_start(void) /* We are sending this now, but the CPUs will be resumed shortly later */ qapi_event_send_resume(); - replay_enable_events(); cpu_enable_ticks(); runstate_set(RUN_STATE_RUNNING); vm_state_notify(1, RUN_STATE_RUNNING);