From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B011606A31B for ; Tue, 27 Oct 2026 15:10:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=EMLjalLG Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xLiot-0002Tm-Nr; Tue, 27 Oct 2026 11:10:36 -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 1xLio2-0001w0-Ou for qemu-riscv@nongnu.org; Tue, 27 Oct 2026 11:09:43 -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 1xLio0-0000jQ-Bm for qemu-riscv@nongnu.org; Tue, 27 Oct 2026 11:09:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1793113779; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YxsqXTT/2SkHCopDBU3zcdHUWKG0aEgc5S4iUgZigFw=; b=EMLjalLGTYrNlCmGo2atTSKdh+ic+WcxN8E92twoOTqF6Og6d7Ro1qC5G68B9x+KITzduw qiYY1++St98785pl7l2SO/CwiUAv/+7ZqPLTHo6xDN2dpBAexTzzjZeL5IPdb2fNqv7OC5 4yce7LK74VH32Pa60OAsm6URxDJgQqY= Received: from mx-prod-mc-03.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-438-7XFlFRhPPtuZJx-cX-8Sxg-1; Tue, 27 Oct 2026 11:09:34 -0400 X-MC-Unique: 7XFlFRhPPtuZJx-cX-8Sxg-1 X-Mimecast-MFC-AGG-ID: 7XFlFRhPPtuZJx-cX-8Sxg_1793113770 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 46A391954B0B; Tue, 27 Oct 2026 15:09:28 +0000 (UTC) Received: from redhat.com (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E918918002B1; Tue, 27 Oct 2026 15:09:01 +0000 (UTC) Date: Tue, 27 Oct 2026 15:08:58 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Markus Armbruster Cc: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , qemu-devel@nongnu.org, Michael Roth , John Snow , Peter Maydell , Mauro Carvalho Chehab , Pierrick Bouvier , Paolo Bonzini , Kostiantyn Kostiuk , Eric Blake , David Hildenbrand , Igor Mammedov , "Edgar E. Iglesias" , Jason Wang , Marcelo Tosatti , kvm@vger.kernel.org, Alberto Garcia , Kevin Wolf , Hanna Reitz , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Zhao Liu , Jonathan Cameron , Junjie Cao , Anisa Su , Elena Ufimtseva , Jagannathan Raman , John Levon , Thanos Makatos , =?utf-8?Q?C=C3=A9dric?= Le Goater , Cornelia Huck , Eric Farman , Matthew Rosato , Richard Henderson , Ilya Leoshkevich , qemu-block@nongnu.org, linux-cxl@vger.kernel.org, qemu-s390x@nongnu.org, "Michael S. Tsirkin" , Sergio Lopez , qemu-arm@nongnu.org, Palmer Dabbelt , Alistair Francis , Weiwei Li , Daniel Henrique Barboza , Liu Zhiwei , Chao Liu , qemu-riscv@nongnu.org, Song Gao <17746591750@163.com>, Bibo Mao , Xianglai Li , Jiaxun Yang , Pedro Barbuda , Mohamed Mediouni , Nicholas Piggin , Harsh Prateek Bora , Amit Machhiwal , qemu-ppc@nongnu.org, Zhang Chen , Li Zhijian , Alistair Francis , Alexander Graf , "Gonglei (Arei)" , zhenwei pi , Ani Sinha , Luc Michel , =?utf-8?Q?C=C3=A9dric?= Le Goater , Jamin Lin , Kane Chen , Samuel Tardieu , "Denis V. Lunev" , FangSheng Huang , Tyrone Ting , Hao Wu , Keith Busch , Klaus Jensen , Jesper Devantier , Aditya Gupta , Glenn Miles , Conor Dooley , Sebastian Huber , Halil Pasic , Christian Borntraeger , Jason Herne , Titus Rwantare , Stefano Stabellini , Anthony PERARD , Peter Xu , Chinmay Rath , Hendrik Brueckner , xen-devel@lists.xenproject.org, Roman Bolshakov , Phil Dennis-Jordan , Fam Zheng , Farhan Ali , Alex Williamson , Tao Tang , Stefan Berger , Fabiano Rosas , Mark Cave-Ayland , Artyom Tarasenko , Yoshinori Sato , Jiri Pirko , Eric Auger , Laurent Vivier Subject: Re: [PATCH v7 54/65] qdev: adjust PciDevfn declared type Message-ID: References: <20261020-qom-qapi-v7-0-431a86b02b58@redhat.com> <20261020-qom-qapi-v7-54-431a86b02b58@redhat.com> <87zevz5h4k.fsf@pond.sub.org> X-Archived-By: MIME-Version: 1.0 In-Reply-To: <87zevz5h4k.fsf@pond.sub.org> User-Agent: Mutt/2.4.2 (2026-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-MFC-PROC-ID: RgrdJLLaMjQ5gITuma7aChvKnkr9uZTznRdPECZXGEo_1793113770 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit 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: 5 X-Spam_score: 0.5 X-Spam_bar: / X-Spam_report: (0.5 / 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, GB_FAKE_RF=0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=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-riscv@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Sender: qemu-riscv-bounces+qemu-riscv=archiver.kernel.org@nongnu.org X-Spam-Status: No, score=-7.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Tue, Oct 27, 2026 at 03:54:03PM +0100, Markus Armbruster wrote: > Marc-André Lureau writes: > > > Hi > > > > On Fri, Oct 23, 2026 at 2:04 PM Daniel P. Berrangé wrote: > >> > >> On Tue, Oct 20, 2026 at 02:46:11PM +0400, Marc-André Lureau wrote: > >> > PciDevfn is a bit special, since it accepts integer and string as > >> > setter, but only output integer as getter. snip > > But I agree we > > could do better. > > > > There are multiple options. We could keep declaring the property as > > str instead. In this case, the getter should probably return a string > > for consistency and correctness. This might surprise some existing > > users though. > > I.e. ditch numeric suppport for numeric addresses, right? > > Incompatible change. Do we care? > > If we don't, we should be honest about it and mark qom-get unstable. > > > We could introduce new properties like `devfn-str` and `devfn-int` > > that alias the same value. > > Compatibility break. If breaking compatibility is okay, I'd rather use > the opportunity to get rid of cleverness, and go with your first option. > > > We could also introduce a new structured QAPI type. > > What kind of type do you have in mind? IMHO the root cause design flaw here was to overload 'addr' as a way to set both the slot number and function number, as using one property for two pieces of data is a well known anti-pattern we caution against. IOW, we should have had 'slot' and 'function' as separate properties from the start. >From a CLI POV, we could easily change 'addr' to mean only the slot number, since it is always parsed in string format without the magic (slot << 4) | function encoding. Then add a 'function' prop The challenge is the impact on QMP with strict typing, as ideally int format would soley represent the slot number, but today the int format is encoded (slot << 4) | function. So anyone relying on int format in QMP would silently have a semantic change if we altered what 'addr' means. Deprecating 'addr' entirely and adding brand new 'slot' and 'function' properties would be a significant disruption to a syntax which has been documented for years (decades). With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|