From nobody Sat Oct 25 19:42:11 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 1518006159424207.2030681592155; Wed, 7 Feb 2018 04:22:39 -0800 (PST) Received: from localhost ([::1]:57303 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOkI-0000Se-IC for importer@patchew.org; Wed, 07 Feb 2018 07:22:38 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50593) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOTy-0001Ra-O9 for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:05:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ejOTw-0004aZ-91 for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:05:45 -0500 Received: from mail.ispras.ru ([83.149.199.45]:47748) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejOTw-0004aP-1e for qemu-devel@nongnu.org; Wed, 07 Feb 2018 07:05:44 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 30DE854008B; Wed, 7 Feb 2018 15:05:43 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 07 Feb 2018 15:05:45 +0300 Message-ID: <20180207120545.5389.69361.stgit@pasha-VirtualBox> In-Reply-To: <20180207120353.5389.54531.stgit@pasha-VirtualBox> References: <20180207120353.5389.54531.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] [RFC PATCH v6 20/20] 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, quintela@redhat.com, ciro.santilli@gmail.com, jasowang@redhat.com, mst@redhat.com, zuban32s@gmail.com, maria.klimushenkova@ispras.ru, dovgaluk@ispras.ru, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, pbonzini@redhat.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 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 7ea4023..e773e68 100644 --- a/block/io.c +++ b/block/io.c @@ -31,6 +31,7 @@ #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 @@ -407,6 +408,13 @@ void bdrv_drain_all_begin(void) BdrvNextIterator it; GSList *aio_ctxs =3D NULL, *ctx; =20 + /* 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 th= read * or the main loop AioContext. We potentially use BDRV_POLL_WHILE() on * nodes in several different AioContexts, so make sure we're in the m= ain @@ -458,6 +466,13 @@ void bdrv_drain_all_end(void) BlockDriverState *bs; BdrvNextIterator it; =20 + /* bdrv queue is managed by record/replay, + waiting for finishing the I/O requests may + be endless */ + if (replay_events_enabled()) { + return; + } + for (bs =3D bdrv_first(&it); bs; bs =3D bdrv_next(&it)) { AioContext *aio_context =3D bdrv_get_aio_context(bs); =20 @@ -1839,6 +1854,13 @@ 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 c1821ae..5185274 100644 --- a/cpus.c +++ b/cpus.c @@ -1005,7 +1005,6 @@ static int do_vm_stop(RunState state) } =20 bdrv_drain_all(); - replay_disable_events(); ret =3D bdrv_flush_all(); =20 return ret; @@ -1987,7 +1986,6 @@ int vm_prepare_start(void) qapi_event_send_stop(&error_abort); res =3D -1; } else { - replay_enable_events(); cpu_enable_ticks(); runstate_set(RUN_STATE_RUNNING); vm_state_notify(1, RUN_STATE_RUNNING);