From patchwork Tue Sep 20 12:31:38 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 9341595 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 17E3C6077A for ; Tue, 20 Sep 2016 12:36:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 06C7F2964F for ; Tue, 20 Sep 2016 12:36:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EF77529652; Tue, 20 Sep 2016 12:36:35 +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=-6.9 required=2.0 tests=BAYES_00,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 1F0352964F for ; Tue, 20 Sep 2016 12:36:35 +0000 (UTC) Received: from localhost ([::1]:34846 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmKHq-00086j-8n for patchwork-qemu-devel@patchwork.kernel.org; Tue, 20 Sep 2016 08:36:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44676) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmKDF-0004Wp-17 for qemu-devel@nongnu.org; Tue, 20 Sep 2016 08:31:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bmKD9-0000im-NP for qemu-devel@nongnu.org; Tue, 20 Sep 2016 08:31:47 -0400 Received: from mail.ispras.ru ([83.149.199.45]:57796) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmKD9-0000fU-CJ for qemu-devel@nongnu.org; Tue, 20 Sep 2016 08:31:43 -0400 Received: from PASHA-ISP.def.inno (unknown [85.142.117.224]) by mail.ispras.ru (Postfix) with ESMTPSA id 571CF54006B; Tue, 20 Sep 2016 15:31:36 +0300 (MSK) To: qemu-devel@nongnu.org From: Pavel Dovgalyuk Date: Tue, 20 Sep 2016 15:31:38 +0300 Message-ID: <20160920123138.5400.67174.stgit@PASHA-ISP.def.inno> In-Reply-To: <20160920123126.5400.29283.stgit@PASHA-ISP.def.inno> References: <20160920123126.5400.29283.stgit@PASHA-ISP.def.inno> User-Agent: StGit/0.16 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 v3 2/8] block: set snapshot option for block devices in blkreplay module 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, jasowang@redhat.com, pbonzini@redhat.com, mst@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP This patch adds overlay option for blkreplay filter. It allows creating persistent overlay file for saving and reloading VM snapshots in record/replay modes. Signed-off-by: Pavel Dovgalyuk --- block/blkreplay.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++++ docs/replay.txt | 8 ++++ vl.c | 2 - 3 files changed, 128 insertions(+), 1 deletion(-) diff --git a/block/blkreplay.c b/block/blkreplay.c index 30f9d5f..e90d2c6 100644 --- a/block/blkreplay.c +++ b/block/blkreplay.c @@ -14,6 +14,7 @@ #include "block/block_int.h" #include "sysemu/replay.h" #include "qapi/error.h" +#include "qapi/qmp/qstring.h" typedef struct Request { Coroutine *co; @@ -25,11 +26,82 @@ typedef struct Request { block devices should not get overlapping ids. */ static uint64_t request_id; +static BlockDriverState *blkreplay_append_snapshot(BlockDriverState *bs, + int flags, + QDict *snapshot_options, + Error **errp) +{ + int ret; + BlockDriverState *bs_snapshot; + + /* Create temporary file, if needed */ + if ((flags & BDRV_O_TEMPORARY) || replay_mode == REPLAY_MODE_RECORD) { + int64_t total_size; + QemuOpts *opts = NULL; + const char *tmp_filename = qdict_get_str(snapshot_options, + "file.filename"); + + /* Get the required size from the image */ + total_size = bdrv_getlength(bs); + if (total_size < 0) { + error_setg_errno(errp, -total_size, "Could not get image size"); + goto out; + } + + opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0, + &error_abort); + qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort); + ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp); + qemu_opts_del(opts); + if (ret < 0) { + error_prepend(errp, "Could not create temporary overlay '%s': ", + tmp_filename); + goto out; + } + } + + bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp); + snapshot_options = NULL; + if (!bs_snapshot) { + ret = -EINVAL; + goto out; + } + + /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will + * call bdrv_unref() on it), so in order to be able to return one, we have + * to increase bs_snapshot's refcount here */ + bdrv_ref(bs_snapshot); + bdrv_append(bs_snapshot, bs); + + return bs_snapshot; + +out: + QDECREF(snapshot_options); + return NULL; +} + +static QemuOptsList blkreplay_runtime_opts = { + .name = "blkreplay", + .head = QTAILQ_HEAD_INITIALIZER(blkreplay_runtime_opts.head), + .desc = { + { + .name = "overlay", + .type = QEMU_OPT_STRING, + .help = "Optional overlay file for snapshots", + }, + { /* end of list */ } + }, +}; + static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { Error *local_err = NULL; int ret; + QDict *snapshot_options = qdict_new(); + int snapshot_flags = BDRV_O_RDWR; + const char *snapshot; + QemuOpts *opts = NULL; /* Open the image file */ bs->file = bdrv_open_child(NULL, options, "image", @@ -40,6 +112,43 @@ static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } + opts = qemu_opts_create(&blkreplay_runtime_opts, NULL, 0, &error_abort); + qemu_opts_absorb_qdict(opts, options, &local_err); + if (local_err) { + ret = -EINVAL; + goto fail; + } + + /* Prepare options QDict for the overlay file */ + qdict_put(snapshot_options, "file.driver", + qstring_from_str("file")); + qdict_put(snapshot_options, "driver", + qstring_from_str("qcow2")); + + snapshot = qemu_opt_get(opts, "overlay"); + if (snapshot) { + qdict_put(snapshot_options, "file.filename", + qstring_from_str(snapshot)); + } else { + char tmp_filename[PATH_MAX + 1]; + ret = get_tmp_filename(tmp_filename, PATH_MAX + 1); + if (ret < 0) { + error_setg_errno(errp, -ret, "Could not get temporary filename"); + goto fail; + } + qdict_put(snapshot_options, "file.filename", + qstring_from_str(tmp_filename)); + snapshot_flags |= BDRV_O_TEMPORARY; + } + + /* Add temporary snapshot to preserve the image */ + if (!blkreplay_append_snapshot(bs->file->bs, snapshot_flags, + snapshot_options, &local_err)) { + ret = -EINVAL; + error_propagate(errp, local_err); + goto fail; + } + ret = 0; fail: if (ret < 0) { @@ -50,6 +159,7 @@ fail: static void blkreplay_close(BlockDriverState *bs) { + bdrv_unref(bs->file->bs); } static int64_t blkreplay_getlength(BlockDriverState *bs) @@ -135,6 +245,12 @@ static int coroutine_fn blkreplay_co_flush(BlockDriverState *bs) return ret; } +static bool blkreplay_recurse_is_first_non_filter(BlockDriverState *bs, + BlockDriverState *candidate) +{ + return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate); +} + static BlockDriver bdrv_blkreplay = { .format_name = "blkreplay", .protocol_name = "blkreplay", @@ -150,6 +266,9 @@ static BlockDriver bdrv_blkreplay = { .bdrv_co_pwrite_zeroes = blkreplay_co_pwrite_zeroes, .bdrv_co_pdiscard = blkreplay_co_pdiscard, .bdrv_co_flush = blkreplay_co_flush, + + .is_filter = true, + .bdrv_recurse_is_first_non_filter = blkreplay_recurse_is_first_non_filter, }; static void bdrv_blkreplay_init(void) diff --git a/docs/replay.txt b/docs/replay.txt index 347b2ff..5be8f25 100644 --- a/docs/replay.txt +++ b/docs/replay.txt @@ -196,6 +196,14 @@ is recorded to the log. In replay phase the queue is matched with events read from the log. Therefore block devices requests are processed deterministically. +blkdriver also supports overlay option, which allows creating persistent +overlay file for saving and reloading VM snapshots in record/replay modes. +Replay mechanism automatically creates one snapshot named 'replay_init' to +allow rewinding execution while replaying. +Overlay file may be specified as follows: + -drive driver=blkreplay,if=none,image=img-direct, + overlay=overlay.qcow2,id=img-blkreplay + Network devices --------------- diff --git a/vl.c b/vl.c index fd7f17e..9adca19 100644 --- a/vl.c +++ b/vl.c @@ -4410,7 +4410,7 @@ int main(int argc, char **argv, char **envp) } /* open the virtual block devices */ - if (snapshot || replay_mode != REPLAY_MODE_NONE) { + if (snapshot) { qemu_opts_foreach(qemu_find_opts("drive"), drive_enable_snapshot, NULL, NULL); }