From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD668C388F9 for ; Wed, 21 Oct 2020 16:29:29 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EA9D420870 for ; Wed, 21 Oct 2020 16:29:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KUTELQ3B" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EA9D420870 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33306 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kVGzO-0003da-05 for qemu-devel@archiver.kernel.org; Wed, 21 Oct 2020 12:29:26 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59188) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kVGxJ-0001lT-G3 for qemu-devel@nongnu.org; Wed, 21 Oct 2020 12:27:17 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:47219) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kVGxH-0004r8-EE for qemu-devel@nongnu.org; Wed, 21 Oct 2020 12:27:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603297634; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=+Yr2Q8JnzLSCFDrPaSlvO5t4dNpfXXKLArO6rsxbTmY=; b=KUTELQ3BuK3PhotWZLua5f8hyuBfkOAGZY9UNla3EvAlmhVLSQRibwj1ELAFF9zEmWIyDa fqMVDaGYcuo/WtNeM/WTVmUupk74yG+xPhlcdd2NljtM89ir6dwglM/ehWooIBlWRukVvL DGxYm/XEb/g9BHGaX5zK2hWfq91BNyA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-329-uTcvREGkOwGpbEzCG_GI0w-1; Wed, 21 Oct 2020 12:27:11 -0400 X-MC-Unique: uTcvREGkOwGpbEzCG_GI0w-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7DCBD5F9D4; Wed, 21 Oct 2020 16:27:10 +0000 (UTC) Received: from localhost.localdomain.com (unknown [10.36.110.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6B3261002388; Wed, 21 Oct 2020 16:27:05 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Subject: [PATCH v7 00/11] migration: bring improved savevm/loadvm/delvm to QMP Date: Wed, 21 Oct 2020 17:26:53 +0100 Message-Id: <20201021162704.3652555-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/21 02:16:02 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Peter Krempa , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , "Denis V. Lunev" , qemu-block@nongnu.org, Juan Quintela , John Snow , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , "Dr. David Alan Gilbert" , Max Reitz , Pavel Dovgalyuk , Paolo Bonzini , Markus Armbruster Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" v1: https://lists.gnu.org/archive/html/qemu-devel/2020-07/msg00866.html=0D v2: https://lists.gnu.org/archive/html/qemu-devel/2020-07/msg07523.html=0D v3: https://lists.gnu.org/archive/html/qemu-devel/2020-08/msg07076.html=0D v4: https://lists.gnu.org/archive/html/qemu-devel/2020-09/msg05221.html=0D v5: https://lists.gnu.org/archive/html/qemu-devel/2020-10/msg00587.html=0D v6: https://lists.gnu.org/archive/html/qemu-devel/2020-10/msg02158.html=0D =0D This series aims to provide a better designed replacement for the=0D savevm/loadvm/delvm HMP commands, which despite their flaws continue=0D to be actively used in the QMP world via the HMP command passthrough=0D facility.=0D =0D The main problems addressed are:=0D =0D - The logic to pick which disk to store the vmstate in is not=0D satsifactory.=0D =0D The first block driver state cannot be assumed to be the root disk=0D image, it might be OVMF varstore and we don't want to store vmstate=0D in there.=0D =0D - The logic to decide which disks must be snapshotted is hardwired=0D to all disks which are writable=0D =0D Again with OVMF there might be a writable varstore, but this can be=0D raw rather than qcow2 format, and thus unable to be snapshotted.=0D While users might wish to snapshot their varstore, in some/many/most=0D cases it is entirely uneccessary. Users are blocked from snapshotting=0D their VM though due to this varstore.=0D =0D - The commands are synchronous blocking execution and returning=0D errors immediately.=0D =0D This is partially addressed by integrating with the job framework.=0D This forces the client to use the async commands to determine=0D the completion status or error message from the operations.=0D =0D In the block code I've only dealt with node names for block devices, as=0D IIUC, this is all that libvirt should need in the -blockdev world it now=0D lives in. IOW, I've made not attempt to cope with people wanting to use=0D these QMP commands in combination with -drive args, as libvirt will=0D never use -drive with a QEMU new enough to have these new commands.=0D =0D The main limitations of this current impl=0D =0D - The snapshot process runs serialized in the main thread. ie QEMU=0D guest execution is blocked for the duration. The job framework=0D lets us fix this in future without changing the QMP semantics=0D exposed to the apps.=0D =0D - Most vmstate loading errors just go to stderr, as they are not=0D using Error **errp reporting. Thus the job framework just=0D reports a fairly generic message=0D =0D "Error -22 while loading VM state"=0D =0D Again this can be fixed later without changing the QMP semantics=0D exposed to apps.=0D =0D I've done some minimal work in libvirt to start to make use of the new=0D commands to validate their functionality, but this isn't finished yet.=0D =0D My ultimate goal is to make the GNOME Boxes maintainer happy again by=0D having internal snapshots work with OVMF:=0D =0D https://gitlab.gnome.org/GNOME/gnome-boxes/-/commit/c486da262f6566326fbcb= 5e=3D=0D f45c5f64048f16a6e=0D =0D Changed in v7:=0D =0D - Incorporate changes from:=0D =0D https://lists.gnu.org/archive/html/qemu-devel/2020-10/msg03165.html=0D =0D - Tweaked error message=0D =0D Changed in v6:=0D =0D - Resolve many conflicts with recent replay changes=0D - Misc typos in QAPI=0D =0D Changed in v5:=0D =0D - Fix prevention of tag overwriting=0D - Refactor and expand test suite coverage to validate=0D more negative scenarios=0D =0D Changed in v4:=0D =0D - Make the device lists mandatory, dropping all support for=0D QEMU's built-in heuristics to select devices.=0D =0D - Improve some error reporting and I/O test coverage=0D =0D Changed in v3:=0D =0D - Schedule a bottom half to escape from coroutine context in=0D the jobs. This is needed because the locking in the snapshot=0D code goes horribly wrong when run from a background coroutine=0D instead of the main event thread.=0D =0D - Re-factor way we iterate over devices, so that we correctly=0D report non-existant devices passed by the user over QMP.=0D =0D - Add QAPI docs notes about limitations wrt vmstate error=0D reporting (it all goes to stderr not an Error **errp)=0D so QMP only gets a fairly generic error message currently.=0D =0D - Add I/O test to validate many usage scenarios / errors=0D =0D - Add I/O test helpers to handle QMP events with a deterministic=0D ordering=0D =0D - Ensure 'delete-snapshot' reports an error if requesting=0D delete from devices that don't support snapshot, instead of=0D silently succeeding with no erro.=0D =0D Changed in v2:=0D =0D - Use new command names "snapshot-{load,save,delete}" to make it=0D clear that these are different from the "savevm|loadvm|delvm"=0D as they use the Job framework=0D =0D - Use an include list for block devs, not an exclude list=0D =0D Daniel P. Berrang=3DC3=3DA9 (10):=0D block: push error reporting into bdrv_all_*_snapshot functions=0D migration: stop returning errno from load_snapshot()=0D block: add ability to specify list of blockdevs during snapshot=0D block: allow specifying name of block device for vmstate storage=0D block: rename and alter bdrv_all_find_snapshot semantics=0D migration: control whether snapshots are ovewritten=0D migration: wire up support for snapshot device selection=0D migration: introduce a delete_snapshot wrapper=0D iotests: add support for capturing and matching QMP events=0D migration: introduce snapshot-{save,load,delete} QMP commands=0D =0D Philippe Mathieu-Daud=3DC3=3DA9 (1):=0D migration: Make save_snapshot() return bool, not 0/-1=0D =0D block/monitor/block-hmp-cmds.c | 7 +-=0D block/snapshot.c | 256 +++++++++++++++------=0D include/block/snapshot.h | 23 +-=0D include/migration/snapshot.h | 47 +++-=0D migration/savevm.c | 294 ++++++++++++++++++++----=0D monitor/hmp-cmds.c | 12 +-=0D qapi/job.json | 9 +-=0D qapi/migration.json | 121 ++++++++++=0D replay/replay-debugging.c | 12 +-=0D replay/replay-snapshot.c | 5 +-=0D softmmu/vl.c | 2 +-=0D tests/qemu-iotests/267.out | 12 +-=0D tests/qemu-iotests/310 | 385 +++++++++++++++++++++++++++++++=0D tests/qemu-iotests/310.out | 407 +++++++++++++++++++++++++++++++++=0D tests/qemu-iotests/common.qemu | 107 ++++++++-=0D tests/qemu-iotests/group | 1 +=0D 16 files changed, 1548 insertions(+), 152 deletions(-)=0D create mode 100755 tests/qemu-iotests/310=0D create mode 100644 tests/qemu-iotests/310.out=0D =0D --=3D20=0D 2.26.2=0D =0D