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 AD282C4332F for ; Tue, 15 Nov 2022 07:54:14 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ouqlP-0000Rr-Vt; Tue, 15 Nov 2022 02:53:48 -0500 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 1ouqlO-0000RH-Ah for qemu-devel@nongnu.org; Tue, 15 Nov 2022 02:53:46 -0500 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 1ouqlM-00040O-Qu for qemu-devel@nongnu.org; Tue, 15 Nov 2022 02:53:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668498822; 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: in-reply-to:in-reply-to:references:references; bh=JTlm0oXYFlORn4gYuJM6c7Tb1hIYFjULgTZQkrjiQvs=; b=CjLv9TerspwFheAR1IL+h9SAZn4+S/5IMIVbSUZLgP6IW1o7aGF5y/AqiX3BkGH1WJ3iOn ljBoDmbm7MQMEun9phmGKMDdX7ADDdgTTPKjR4B9yO+pZYDg1rGaLJpayNkFkuTJf50238 0iv6QnbjDilxbljrIxz5jabBBhOqsQo= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-263-wpvmBZdbNXiaSN9eRvAs6Q-1; Tue, 15 Nov 2022 02:53:38 -0500 X-MC-Unique: wpvmBZdbNXiaSN9eRvAs6Q-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 080D6185A794; Tue, 15 Nov 2022 07:53:38 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.175]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C897D2166B41; Tue, 15 Nov 2022 07:53:37 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id AD5A621E6921; Tue, 15 Nov 2022 08:53:34 +0100 (CET) From: Markus Armbruster To: Thomas Huth Cc: Paolo Bonzini , qemu-devel@nongnu.org, qemu-s390x@nongnu.org, Matthew Rosato , Tony Krowiak , =?utf-8?Q?C=C3=A9dric?= Le Goater , Marcel Apfelbaum Subject: Re: [PATCH v2] util/qemu-config: Fix "query-command-line-options" to provide the right values References: <20221111141323.246267-1-thuth@redhat.com> <875yflbl0u.fsf@pond.sub.org> Date: Tue, 15 Nov 2022 08:53:34 +0100 In-Reply-To: (Thomas Huth's message of "Fri, 11 Nov 2022 17:36:18 +0100") Message-ID: <87leocwt4x.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@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_H2=-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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Thomas Huth writes: > On 11/11/2022 15.53, Markus Armbruster wrote: >> Thomas Huth writes: >> >>> The "query-command-line-options" command uses a hand-crafted list >>> of options that should be returned for the "machine" parameter. >>> This is pretty much out of sync with reality, for example settings >>> like "kvm_shadow_mem" or "accel" are not parameters for the machine >>> anymore. Also, there is no distinction between the targets here, so >>> e.g. the s390x-specific values like "loadparm" in this list also >>> show up with the other targets like x86_64. >>> >>> Let's fix this now by geting rid of the hand-crafted list and by >>> querying the properties of the machine classes instead to assemble >>> the list. >> Do we know what uses this command, and how these users are >> inconvenienced by the flaw you're fixing? >> I'm asking because the command is pretty much out of sync with reality >> by (mis-)design. > > libvirt apparently queries this data (see the various tests/qemucapabilitiesdata/*.replies files in their repository), but since > it's so much out-of-sync with reality, it's not of a big use there yet. > > See for example here: > > https://lists.gnu.org/archive/html/qemu-devel/2021-12/msg00581.html > > If we finally fix this problem with "query-command-line-options" in QEMU, it should be much easier to deprecate -no-hpet in QEMU, too. For a value of "fix". While we can fix certain concrete issues with q-c-l-o, which may be wortwhile, the overarching issue is (in my opinion) unfixable: it can only tell us about QemuOpts. QemuOpts is only part of the truth. Last time I checked, it worked for one out of five CLI options. Moreover, our needs have long outgrown QemuOpts' design limitations, which has led to a bunch of bolted-on hacks, none of them represented in q-c-l-o.