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 4C14DCA5FDD for ; Fri, 2 Oct 2026 16:33:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xCgBz-0004s8-Jo; Fri, 02 Oct 2026 12:33:03 -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 1xCgBx-0004rb-5X for qemu-arm@nongnu.org; Fri, 02 Oct 2026 12:33:02 -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 1xCgBv-0006fR-6P for qemu-arm@nongnu.org; Fri, 02 Oct 2026 12:33:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1790958776; 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=K1xrRgMuowtJU/AyL7q9uOj6RF4ZlGCwUh9gu4GUDZ4=; b=WHCwmLnGhKuIeTell/Egl/86QggK5dSv0RZaheM1SOTtI/FsRjJ+Efu5N+sqKNxDosDBek ff1ON8axuSyqTt25rj7MfaYvfsWJIDbFbC2wXlFKIrivsFjI8vsZXyyw5lMfa7IaSt/HeS KmHNB0i3Qbtpvq4HY3JYGZBB+CVjVGU= 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-284-r_hgWvEvONea0h5n1yfArA-1; Fri, 02 Oct 2026 12:32:53 -0400 X-MC-Unique: r_hgWvEvONea0h5n1yfArA-1 X-Mimecast-MFC-AGG-ID: r_hgWvEvONea0h5n1yfArA_1790958770 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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9A1921808875; Fri, 2 Oct 2026 16:32:42 +0000 (UTC) Received: from redhat.com (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id F0BD01956086; Fri, 2 Oct 2026 16:32:36 +0000 (UTC) Date: Fri, 2 Oct 2026 17:32:33 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Pierrick Bouvier Cc: luoyonggang@gmail.com, Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, Chao Liu , Eric Blake , qemu-arm@nongnu.org, Paolo Bonzini , Markus Armbruster , Alistair Francis , Brian Cain , Stafford Horne , Peter Maydell , Jiaxun Yang , Fabiano Rosas , Daniel Henrique Barboza , qemu-riscv@nongnu.org, Laurent Vivier , Max Filippov , Song Gao <17746591750@163.com>, Philippe Mathieu-Daude , Palmer Dabbelt , Laurent Vivier , Weiwei Li , Zhao Liu Subject: Re: [PATCH v3 01/10] machine: allow -M name to differ from QOM type Message-ID: References: <26b0d44d-0322-4ceb-a47b-747fc52c61b7@oss.qualcomm.com> <6bf4dad5-4fa2-4df1-b6b8-d594dbd3842c@oss.qualcomm.com> <557262df-b8e7-49b5-a245-ae46b8885b30@oss.qualcomm.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.4.2 (2026-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Mimecast-MFC-PROC-ID: PgskPXUDP3genVGlMCg7wBSOrtvTojgYcFftBCzbN7I_1790958770 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: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.336, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-arm@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-arm-bounces+qemu-arm=archiver.kernel.org@nongnu.org Sender: qemu-arm-bounces+qemu-arm=archiver.kernel.org@nongnu.org On Fri, Oct 02, 2026 at 08:40:54AM -0700, Pierrick Bouvier wrote: > On 10/1/2026 7:00 PM, Yonggang Luo wrote: > > On Fri, Oct 2, 2026 at 2:56 AM Pierrick Bouvier > > wrote: > >> > >> On 10/1/2026 11:26 AM, Daniel P. Berrangé wrote: > >>> On Thu, Oct 01, 2026 at 11:08:17AM -0700, Pierrick Bouvier wrote: > >>>> On 10/1/2026 10:40 AM, Daniel P. Berrangé wrote: > >>>>> Even with the current per-target binaries there are countless > >>>>> devices linked in which are incompatible / not usable with > >>>>> certain machine types. A new multi-target binary with a union > >>>>> of all devices will just be a bigger example of a scenario that > >>>>> already has to be dealt with for today's binaries. > >>>>> > >>>>> So if we have that assumption that we don't need to do device > >>>>> filtering, at that point, a --target option doesn't have as > >>>>> big of a role to play. The machine type code knows what target(s) > >>>>> it wants (1 or 2 targets depending on if there are 32 + 64 bit > >>>>> varaints. The CPU model the user requests (if the CPU is not > >>>>> hardcoded by the machine), determines 32 bit vs 64 bit. > >>>>> > >>>> > >>>> How can we deduce this information (bitness or target for existing > >>>> machines/cpus)? > >>> > >>> It would require that we introduce a new field in MachineClass > >>> that returned that information about what target a machine is > >>> associated with. > >>> > >>> I note the SysEmuTarget covers both 32-bit and 64-bit variants. > >>> > >>> It might be better use QEMU_ARCH which correlates directly to > >>> the TCG targets, rather than the traditional binary target > >>> names ? > >>> > >>> Likely the CPU class would also want to declare its list of > >>> supported targets. > >>> > >> > >> QEMU_ARCH only represents base architectures, and not variant, so > >> SysEmuTarget is the right choice. > >> > >> So, we would need a list of SysEmuTarget for every cpu/machine that is > >> target specific, since one could be available for variants of base arch? > > > > For this, adding TargetInfo parameter to is_avaible callback will let us get the > > list of SysEmuTarget for every cpu/machine. As we can iterate on all TargetInfo > > then check if that TargetInfo is present for every cpu/machine. > > And indeed for devices if you want. That's what my patches are already done. > > > > @Daniel: would that work for you? I feel like it limits the way to > introspect qom objects, but maybe not if we export the right thing on > QAPI side based on that. "is_available" is probably a bit overkill as a mechanism for introspecting, when we just need to return a list of targets, Since we have that already we might as well use it initially though. > >> Does it matches what you would expect? > >> > >> Also, for compatibility with existing binaries, should we accept -M > >> $arch-virt also? I feel like it does not hurt and would make thing > >> simpler to switch between existing and new binary. > > > > Same reason -M $arch-virt, indeed like -M $arch:virt, but $arch-virt > > would be even harder. > > Because "-" is a valid separator in machine names, ":" is not a valid > > machine name. > > So without init QOM, we can not reliably identify "$arch-virt" belongs > > to which target. > > > > From the conversation above, Daniel and I are not in favor to have any > kind of parsing based on this string. So either we'll pick virt, or the > real qom name, but not anything else. Yeah, I'm leaning more towards always exposing the $arch-virt names in all binaries, and also exposing 'virt' in the traditional binaries only. 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 :|