From nobody Fri Oct 10 13:16:27 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1545132319017470.6965955501805; Tue, 18 Dec 2018 03:25:19 -0800 (PST) Received: from localhost ([::1]:53220 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZDUx-00058o-Bp for importer@patchew.org; Tue, 18 Dec 2018 06:25:15 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46396) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZDRL-0002XL-NF for qemu-devel@nongnu.org; Tue, 18 Dec 2018 06:21:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gZDRI-0005g0-Da for qemu-devel@nongnu.org; Tue, 18 Dec 2018 06:21:31 -0500 Received: from mail.ispras.ru ([83.149.199.45]:55390) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZDRG-0005du-Cg for qemu-devel@nongnu.org; Tue, 18 Dec 2018 06:21:28 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 77FD254006A; Tue, 18 Dec 2018 14:21:23 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Tue, 18 Dec 2018 14:21:25 +0300 Message-ID: <20181218112125.11727.64882.stgit@pasha-VirtualBox> In-Reply-To: <20181218112056.11727.96529.stgit@pasha-VirtualBox> References: <20181218112056.11727.96529.stgit@pasha-VirtualBox> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 83.149.199.45 Subject: [Qemu-devel] [PATCH v8 05/20] 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" 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" =20 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progr= ess */ =20 @@ -538,6 +539,13 @@ void bdrv_drain_all_begin(void) return; } =20 + /* 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 ma= in * loop AioContext, so make sure we're in the main context. */ assert(qemu_get_current_aio_context() =3D=3D qemu_get_aio_context()); @@ -566,6 +574,13 @@ void bdrv_drain_all_end(void) { BlockDriverState *bs =3D NULL; =20 + /* bdrv queue is managed by record/replay, + waiting for finishing the I/O requests may + be endless */ + if (replay_events_enabled()) { + return; + } + while ((bs =3D bdrv_next_all_states(bs))) { AioContext *aio_context =3D bdrv_get_aio_context(bs); =20 @@ -1997,6 +2012,13 @@ int bdrv_flush_all(void) BlockDriverState *bs =3D NULL; int result =3D 0; =20 + /* 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 =3D bdrv_first(&it); bs; bs =3D bdrv_next(&it)) { AioContext *aio_context =3D bdrv_get_aio_context(bs); int ret; diff --git a/cpus.c b/cpus.c index 0ddeeef..5a0697b 100644 --- a/cpus.c +++ b/cpus.c @@ -1078,7 +1078,6 @@ static int do_vm_stop(RunState state, bool send_stop) } =20 bdrv_drain_all(); - replay_disable_events(); ret =3D bdrv_flush_all(); =20 return ret; @@ -2148,7 +2147,6 @@ int vm_prepare_start(void) /* We are sending this now, but the CPUs will be resumed shortly later= */ qapi_event_send_resume(); =20 - replay_enable_events(); cpu_enable_ticks(); runstate_set(RUN_STATE_RUNNING); vm_state_notify(1, RUN_STATE_RUNNING);