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 lists1p.gnu.org (lists1p.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 CB46BC44508 for ; Fri, 10 Jul 2026 06:27:47 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wi4gA-0007uB-6y; Fri, 10 Jul 2026 02:25:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wi4g0-0007kj-RF for qemu-devel@nongnu.org; Fri, 10 Jul 2026 02:25:35 -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 1wi4fz-0005pQ-En for qemu-devel@nongnu.org; Fri, 10 Jul 2026 02:25:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783664730; 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=v8q+3lUkMrowihgNvWTsOWIW9MlqhSBHDx1C+VszfsU=; b=Y8qxUmyI6hJK+pmkUoskHlceV58TFTMFR45ieC1huMTeDxs2CXIcLobsYvW1hqcNnkffdq O1vmwWMkWxEt0ze+otVlKvTGFWnwdJl0NtOybDXTVgq3tfgGGDrxYCWhOpuh1KNJ99ojtB /mGegdxouREKu2krz3Boodt253MKuFk= Received: from mx-prod-mc-01.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-612-C-trBSPRMYWc0_bCbg-Gww-1; Fri, 10 Jul 2026 02:25:27 -0400 X-MC-Unique: C-trBSPRMYWc0_bCbg-Gww-1 X-Mimecast-MFC-AGG-ID: C-trBSPRMYWc0_bCbg-Gww_1783664721 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 370881955F76; Fri, 10 Jul 2026 06:25:19 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.44.22.4]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A8F05180058C; Fri, 10 Jul 2026 06:25:15 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 380D421E6920; Fri, 10 Jul 2026 08:25:13 +0200 (CEST) From: Markus Armbruster To: "Graf (AWS), Alexander" Cc: BALATON Zoltan , Markus Armbruster , "qemu-devel@nongnu.org" , Aditya Gupta , Alexandre Iooss , "Alexey Kardashevskiy" , Alistair Francis , Alistair Francis , Antony Pavlov , Artyom Tarasenko , "Bernhard Beschow" , Bibo Mao , Brian Cain , Chao Liu , Christian Borntraeger , =?utf-8?Q?Cl=C3=A9me?= =?utf-8?Q?nt?= Chigot , =?utf-8?Q?C=C3=A9dric?= Le Goater , Dorjoy Chowdhury , "Edgar E. Iglesias" , Eric Farman , Farhan Ali , "Felipe Balbi" , Francisco Iglesias , Frederic Konrad , Gaurav Sharma , Gautam Gala , Glenn Miles , Halil Pasic , Hao Wu , Harsh Prateek Bora , "Helge Deller" , Hendrik Brueckner , =?utf-8?Q?Herv=C3=A9?= Poussineau , Huacai Chen , Jan Kiszka , Jared Rossi , Joel Stanley , Laurent Vivier , Manos Pitsidianakis , Mark Cave-Ayland , Matthew Rosato , Max Filippov , Michael Rolnik , "Michael S. Tsirkin" , Nicholas Piggin , Niek Linnenbank , "Palmer Dabbelt" , Paolo Bonzini , "Peter Maydell" , Philippe =?utf-8?Q?Mathieu-?= =?utf-8?Q?Daud=C3=A9?= , "Pierrick Bouvier" , Ran Wang , Richard Henderson , Sai Pavan Boddu , Samuel Tardieu , Sergio Lopez , Song Gao <17746591750@163.com>, Stafford Horne , Subbaraya Sundeep , Thomas Huth , Tyrone Ting , "qemu-arm@nongnu.org" , "qemu-ppc@nongnu.org" , "qemu-riscv@nongnu.org" , "qemu-s390x@nongnu.org" Subject: Re: Call to clean up QOM onboard devices lacking a parent In-Reply-To: (Graf Alexander's message of "Thu, 9 Jul 2026 16:45:42 +0000") References: <87se5scipx.fsf@pond.sub.org> <17c7f91b-8935-8ebf-a982-f91df755af81@eik.bme.hu> Date: Fri, 10 Jul 2026 08:25:13 +0200 Message-ID: <87h5m7xsxi.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 8 X-Spam_score: 0.8 X-Spam_bar: / X-Spam_report: (0.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, 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, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development 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 "Graf (AWS), Alexander" writes: > Hi Markus, [...] > I'm also curious on whether there is anything that makes sysbus device > spawns both easy (as they are today) and at the same time fully QOM > parent compliant. > > I had a quick look at the vmapple machine and most of the offenders are > sysbus devices I spawn via qdev_new(). Would you want all of these to > get their parent declared via object_property_add_child()? If that's the > case, why don't we introduce a new qdev_new_child() which does that > automatically? We do have such convenience functions at the QOM layer: object_new() and object_property_add_child() etc., are basic building blocks, and object_new_with_props() etc. combine them in useful ways. We don't have such convenience functions at the qdev layer. Can't see why we couldn't add them. Number of orphaned device types I see by bus_type: 69 busless 15 ISA 33 PCI 11 SSI 209 System 2 apple-desktop-bus 23 i2c-bus 2 sd-bus 1 spapr-vio-bus 2 usb-bus Again, not a problem with the device types, but the code that creates and realizes them. Bus types commonly provide a layer above qdev for that. Perhaps these layers could also use convenience functions to more easily deal with setting the QOM parent.