From patchwork Tue Feb 5 08:20:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 10796999 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 3347013BF for ; Tue, 5 Feb 2019 08:24:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2366F2B127 for ; Tue, 5 Feb 2019 08:24:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 178032B40F; Tue, 5 Feb 2019 08:24:20 +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=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id ACA5F2B127 for ; Tue, 5 Feb 2019 08:24:19 +0000 (UTC) Received: from localhost ([127.0.0.1]:56151 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gqw1i-0001hN-SK for patchwork-qemu-devel@patchwork.kernel.org; Tue, 05 Feb 2019 03:24:18 -0500 Received: from eggs.gnu.org ([209.51.188.92]:52038) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gqvxj-0007rq-3Z for qemu-devel@nongnu.org; Tue, 05 Feb 2019 03:20:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gqvxi-0008AX-3D for qemu-devel@nongnu.org; Tue, 05 Feb 2019 03:20:11 -0500 Received: from mail.ispras.ru ([83.149.199.45]:33422) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gqvxh-0008A0-NQ for qemu-devel@nongnu.org; Tue, 05 Feb 2019 03:20:10 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id CE87E54008A; Tue, 5 Feb 2019 11:20:08 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Tue, 05 Feb 2019 11:20:10 +0300 Message-ID: <154935480995.7509.13012048579786526886.stgit@pasha-VirtualBox> In-Reply-To: <154935478086.7509.4349987292919289245.stgit@pasha-VirtualBox> References: <154935478086.7509.4349987292919289245.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 v12 05/25] 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, crosthwaite.peter@gmail.com, ciro.santilli@gmail.com, jasowang@redhat.com, quintela@redhat.com, armbru@redhat.com, mreitz@redhat.com, alex.bennee@linaro.org, maria.klimushenkova@ispras.ru, mst@redhat.com, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, dovgaluk@ispras.ru, artem.k.pisarenko@gmail.com, 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. Stopping the machine when the IO requests are not finished is needed for the debugging. E.g., breakpoint may be set at the specified step, and forcing the IO requests to finish may break the determinism of the execution. Signed-off-by: Pavel Dovgalyuk --- block/io.c | 28 ++++++++++++++++++++++++++++ cpus.c | 2 -- 2 files changed, 28 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index 213ca03d8d..c25864a8ee 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 +539,15 @@ 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 +576,15 @@ 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); @@ -1998,6 +2017,15 @@ 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 b09b702712..aa33fb15b3 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; @@ -2149,7 +2148,6 @@ 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);