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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 52972C433DB for ; Wed, 20 Jan 2021 14:41:27 +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 E229223356 for ; Wed, 20 Jan 2021 14:41:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E229223356 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]:46546 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l2Efk-0003KP-Qn for qemu-devel@archiver.kernel.org; Wed, 20 Jan 2021 09:41:24 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:34506) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l2EeG-0002Xs-UE for qemu-devel@nongnu.org; Wed, 20 Jan 2021 09:39:54 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:57084) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l2EeC-0003CN-Et for qemu-devel@nongnu.org; Wed, 20 Jan 2021 09:39:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611153587; 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: in-reply-to:in-reply-to:references:references; bh=gpOUc2YQ7OzwDdTbIXdu+aF5mwPNkWiU96kyIsUN7as=; b=ivM34SUKoXr29srXsfhxmDwVo+4nAoWyEty5oBQoPaoIO3l800kh2eodYy+Bxew3Ey2OZn OtKnpmnyDyD9wD/iuHVnPm3wzhA1SLZCEsRWR68E9Ni5a+tPMRCAyQ33WDYpi+nnDkBLmH yddl20iULQrQ0l4KQ7H6jOyw/Wpbk4Q= 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-552-dxpYvbjTOU2NminHjRGFOg-1; Wed, 20 Jan 2021 09:39:44 -0500 X-MC-Unique: dxpYvbjTOU2NminHjRGFOg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C69F610054FF; Wed, 20 Jan 2021 14:39:38 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-113-224.ams2.redhat.com [10.36.113.224]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8E5D4E155; Wed, 20 Jan 2021 14:39:37 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 650EE113865F; Wed, 20 Jan 2021 15:39:36 +0100 (CET) From: Markus Armbruster To: Daniel P. =?utf-8?Q?Berrang=C3=A9?= Subject: Re: [PATCH v9 11/11] migration: introduce snapshot-{save, load, delete} QMP commands References: <20210120104411.3084801-1-berrange@redhat.com> <20210120104411.3084801-12-berrange@redhat.com> Date: Wed, 20 Jan 2021 15:39:36 +0100 In-Reply-To: <20210120104411.3084801-12-berrange@redhat.com> ("Daniel P. =?utf-8?Q?Berrang=C3=A9=22's?= message of "Wed, 20 Jan 2021 10:44:11 +0000") Message-ID: <878s8npt93.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@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=63.128.21.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.167, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, 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 , qemu-block@nongnu.org, Juan Quintela , qemu-devel@nongnu.org, Max Reitz , Pavel Dovgalyuk , Paolo Bonzini , John Snow , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Daniel P. Berrang=C3=A9 writes: > savevm, loadvm and delvm are some of the few HMP commands that have never > been converted to use QMP. The reasons for the lack of conversion are > that they blocked execution of the event thread, and the semantics > around choice of disks were ill-defined. > > Despite this downside, however, libvirt and applications using libvirt > have used these commands for as long as QMP has existed, via the > "human-monitor-command" passthrough command. IOW, while it is clearly > desirable to be able to fix the problems, they are not a blocker to > all real world usage. > > Meanwhile there is a need for other features which involve adding new > parameters to the commands. This is possible with HMP passthrough, but > it provides no reliable way for apps to introspect features, so using > QAPI modelling is highly desirable. > > This patch thus introduces new snapshot-{load,save,delete} commands to > QMP that are intended to replace the old HMP counterparts. The new > commands are given different names, because they will be using the new > QEMU job framework and thus will have diverging behaviour from the HMP > originals. It would thus be misleading to keep the same name. > > While this design uses the generic job framework, the current impl is > still blocking. The intention that the blocking problem is fixed later. > None the less applications using these new commands should assume that > they are asynchronous and thus wait for the job status change event to > indicate completion. > > In addition to using the job framework, the new commands require the > caller to be explicit about all the block device nodes used in the > snapshot operations, with no built-in default heuristics in use. > > Note that the existing "query-named-block-nodes" can be used to query > what snapshots currently exist for block nodes. > > Acked-by: Markus Armbruster > Signed-off-by: Daniel P. Berrang=C3=A9 Looks good to me, my Acked-by stands.