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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 6AA1EC5B552 for ; Mon, 9 Jun 2025 15:44:45 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uOefF-0000J7-69; Mon, 09 Jun 2025 11:43:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uOefD-0000Iv-Ha for qemu-devel@nongnu.org; Mon, 09 Jun 2025 11:43:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uOefB-0007cn-IV for qemu-devel@nongnu.org; Mon, 09 Jun 2025 11:43:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749483830; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=tWtO3c7rv0EFkFLwyztzzsbYAsePJ+sRrt/pUHfl1eg=; b=DclZiwOgOjjEGX0SwP2j8GnNcpxVsQ0uTl/CIMjVa6nCYcFEL2CragBZilKDCoPcaO9OIX IP0/lZ7DWz7fwjgLbG3q0vetMR3mbEJrDnozOY7UBr6ObOoaVT2rf3jdMhaND8t0n8BjeL TJaKfurZx6d86KcEFhbqeVF6Q7Tzs8Y= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-613-uDwBKjn4NCeOB2rB6nzbXg-1; Mon, 09 Jun 2025 11:43:48 -0400 X-MC-Unique: uDwBKjn4NCeOB2rB6nzbXg-1 X-Mimecast-MFC-AGG-ID: uDwBKjn4NCeOB2rB6nzbXg_1749483827 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6976C18089B6; Mon, 9 Jun 2025 15:43:47 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.45]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0886219560AB; Mon, 9 Jun 2025 15:43:44 +0000 (UTC) Date: Mon, 9 Jun 2025 16:43:40 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Peter Xu Cc: Fabiano Rosas , qemu-devel@nongnu.org, Markus Armbruster Subject: Re: [PATCH 19/21] migration: Allow migrate commands to provide the migration config Message-ID: References: <20250603013810.4772-1-farosas@suse.de> <20250603013810.4772-20-farosas@suse.de> <874iwswrex.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Jun 09, 2025 at 11:33:14AM -0400, Peter Xu wrote: > > Now I think I know part of what I've missed: I used to think the "config" > of per-QMP-migrate-command can be totally temporary for a specific > migration request, but then we need another MigrationState.parameters_2 to > cache the old or vice versa; that's probably not necessary. Now I think it > makes sense to overwrite any settings directly, hence I think I changed my > mind on question (1), YES is fine here. > > For (2), why it would introduce any uncertainty for mgmt? > > If the mgmt app can both: (1) query from qapi schema knowing all the > parameters supported, then (2) specify all the parameters in QMP migrate's > "option" parameter. Then it's literally overwritting all the parameters, > so it's predictable with or without completely removing global settings as > an idea? That is relying on the mgmt app specifiying absolutely every config parameter that exists. If they miss anything, then the behaviour is not well defined, as external global state still affects things. This is the same situation we already have with migrate-set-parameter, where mgmt apps have to know to call migrate-set-parameter over & over with every possible parameter to get back to a well known starting point. The command needs to run with the parameters provided in 'config' and no external global state, whether from -global or any prior call of migrate-set-parameter With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|