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 49E0DC369A2 for ; Mon, 14 Apr 2025 16:45:19 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u4Mvb-0004yR-3R; Mon, 14 Apr 2025 12:44:59 -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 1u4MvX-0004x6-O5 for qemu-devel@nongnu.org; Mon, 14 Apr 2025 12:44:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1u4MvR-00076O-OK for qemu-devel@nongnu.org; Mon, 14 Apr 2025 12:44:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744649088; 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=OcN5k9QmrnlyPBXU5Pv3tSyq5MUTn3VgFqSkZxEy3tU=; b=cNx1DAShgv8ELWUTe7tCBJuv8rCvIMtdA4CykmenyxgnonWKdn0XdNhTj+SA4T3x6gxr4K Q9hegI+dCQRUeaRGErhJGdXiLET8PaEyAkYR/+K579qik0zkMooV+Cv+dbFdkD+sA2SWUr fAVPFWUl65ESggy2HeKZ4th9Z4+k68o= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-624-dXf9Qus6MxyqlgBAgmLmgA-1; Mon, 14 Apr 2025 12:44:44 -0400 X-MC-Unique: dXf9Qus6MxyqlgBAgmLmgA-1 X-Mimecast-MFC-AGG-ID: dXf9Qus6MxyqlgBAgmLmgA_1744649083 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3E408195609F; Mon, 14 Apr 2025 16:44:43 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.99]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9317A19560AD; Mon, 14 Apr 2025 16:44:40 +0000 (UTC) Date: Mon, 14 Apr 2025 17:44:37 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Fabiano Rosas Cc: qemu-devel@nongnu.org, Peter Xu , Markus Armbruster Subject: Re: [RFC PATCH 00/13] migration: Unify capabilities and parameters Message-ID: References: <20250411191443.22565-1-farosas@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250411191443.22565-1-farosas@suse.de> User-Agent: Mutt/2.2.13 (2024-03-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.133.124; 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 Fri, Apr 11, 2025 at 04:14:30PM -0300, Fabiano Rosas wrote: > Open questions: > --------------- > > - Deprecations/compat? > > I think we should deprecate migrate-set/query-capabilities and everything to do > with capabilities (specifically the validation in the JSON at the end of the > stream). > > For migrate-set/query-parameters, we could probably keep it around indefinitely, > but it'd be convenient to introduce new commands so we can give them new > semantics. > > - How to restrict the options that should not be set when the migration is in > progress? > > i.e.: > all options can be set before migration (initial config) > some options can be set during migration (runtime) > > I thought of adding another type at the top of the hierarchy, with > just the options allowed to change at runtime, but that doesn't really > stop the others being also set at runtime. I'd need a way to have a > set of options that are rejected 'if migration_is_running()', without > adding more duplication all around. > > - What about savevm? > > None of this solves the issue of random caps/params being set before > calling savevm. We still need to special-case savevm and reject > everything. Unless we entirely deprecate setting initial options via > set-parameters (or set-config) and require all options to be set as > savevm (and migrate) arguments. I'd suggest we aim for a world where the commands take all options as direct args and try to remove the global state eventually. For savevm/loadvm in particular it is very much a foot-gun that 'migrate-set-*' will affect them, because savevm/loadvm aren't obviously connected to 'migrate-*' commands unless you're aware of how QEMU implements savevm internally. > - HMP? > > Can we convert the strings passed via hmp_set_parameters without > having an enum of parameters? Duplication problem again. > > - incoming defer? > > It seems we cannot do the final step of removing > migrate-set-capabilites before we have a form of handshake > implemented. That would take the config from qmp_migrate on source and > send it to the destination for negotiation. I'm not sure I understand why the QAPI design changes are tied to the new protocol handshake ? I guess you're wanting to avoid updating 'migrate_incoming' to accept the new parameters directly ? 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 :|