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 6319AD35175 for ; Wed, 1 Apr 2026 10:44:42 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1w7t3R-00061O-Mh; Wed, 01 Apr 2026 06:44:09 -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 1w7t3M-00060x-Iv for qemu-devel@nongnu.org; Wed, 01 Apr 2026 06:44:04 -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 1w7t3J-0007jc-E9 for qemu-devel@nongnu.org; Wed, 01 Apr 2026 06:44:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1775040240; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aLNFaB231eFX2G1G66v7tit4+h7UWxtF7oHO8IMge+k=; b=Ys+6HzlJUK4rzgQVcsmcZirtko247kjJYKmPVBrernWktbr+r/P/8+Olc/mjHgy1Atp2B4 riLkuUDJOez6IKkkcFoc9CwNrxMQ3mm29BLfiT5IK6n2h2bD9ZKPhtGV8uMVBQSG3DiZ0g OZjqJgM0/k09EkeiCx2F/PQStXjGXtY= Received: from mx-prod-mc-05.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-172-eZQj25foMc6ZMWvId_yBlg-1; Wed, 01 Apr 2026 06:43:56 -0400 X-MC-Unique: eZQj25foMc6ZMWvId_yBlg-1 X-Mimecast-MFC-AGG-ID: eZQj25foMc6ZMWvId_yBlg_1775040235 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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 540AF1956089; Wed, 1 Apr 2026 10:43:54 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.44.22.6]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id F239218001FE; Wed, 1 Apr 2026 10:43:52 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 8A97521E6A28; Wed, 01 Apr 2026 12:43:50 +0200 (CEST) From: Markus Armbruster To: "Sergei Heifetz" Cc: , "Eric Blake" , "Michael S. Tsirkin" , Alex =?utf-8?Q?Benn=C3=A9e?= , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , "Marcel Apfelbaum" , "Paolo Bonzini" , "Fabiano Rosas" , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , "Eduardo Habkost" , "Yanan Wang" , "Zhao Liu" , "Richard Henderson" , "Dr. David Alan Gilbert" , "Thomas Huth" , Daniel P. =?utf-8?Q?Berrang=C3=A9?= , "Laurent Vivier" , "Gerd Hoffmann" , Subject: Re: [PATCH v3 07/11] ui/dbus: run without Audio interface when audio is disabled In-Reply-To: (Sergei Heifetz's message of "Wed, 01 Apr 2026 09:16:01 +0500") References: <20260315201646.96862-1-heifetz@yandex-team.com> <20260315201646.96862-8-heifetz@yandex-team.com> <87ms04cksj.fsf@pond.sub.org> Date: Wed, 01 Apr 2026 12:43:50 +0200 Message-ID: <87cy0j2c61.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 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: 27 X-Spam_score: 2.7 X-Spam_bar: ++ X-Spam_report: (2.7 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.54, 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=-0.01, RCVD_IN_SBL_CSS=3.335, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=1, RCVD_IN_VALIDITY_RPBL_BLOCKED=1, 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 "Sergei Heifetz" writes: > On Thu Mar 19, 2026 at 12:58 PM +05, Markus Armbruster wrote: >> Sergei Heifetz writes: >> >>> D-Bus display can be used even when QEMU is configured with >>> `--disable-audio`. In that case, audio interface will not be available >>> on `/org/qemu/Display1/Audio`. >>> >>> (The current handling of the situation when audio is enabled but >>> no D-Bus-compatible audio backend is available is different and >>> hasn=E2=80=99t been changed.) >>> >>> Signed-off-by: Sergei Heifetz >>> --- >>> qapi/ui.json | 2 +- >>> qemu-options.hx | 4 ++++ >>> ui/dbus.c | 8 ++++++++ >>> 3 files changed, 13 insertions(+), 1 deletion(-) >>> >>> diff --git a/qapi/ui.json b/qapi/ui.json >>> index e3da77632a8..62eb05c6091 100644 >>> --- a/qapi/ui.json >>> +++ b/qapi/ui.json >>> @@ -1385,7 +1385,7 @@ >>> 'data' : { '*rendernode' : 'str', >>> '*addr': 'str', >>> '*p2p': 'bool', >>> - '*audiodev': 'str' } } >>> + '*audiodev': { 'type': 'str', 'if': 'CONFIG_AUDIO' } }= } >> >> Is this a compatibility break? >> >> DisplayDBus is only used in DisplayOptions, which is only used as return >> type of query-display-options in the QAPI schema. However, vl.c also >> uses it to parse -display. >> >> Removing parameter @audiodev from -display is technically a >> compatibility break. However, we're removing an optional paramater that >> would always be rejected when present: it has no valid value, because >> there are no audiodevs. >> >> Removal from query-display-options is similar: it could not be present. >> >> Removal affects introspection, which could conceivably confuse client. >> I don't expect such trouble here, because @audiodev always existed, i.e. >> there's no real reason to look for it in introspection. >> >> I think we're okay. I'm cc'ing the libvirt list just in case. > > These are questions I would like to know the answers to as well. From my > perspective, disabling compilation of the audio subsystem is worth it, > but you should expect to potentially tweak a few audio-related things to > make it work. I agree that technically makes it a compatibility break. > But preserving meaningless parameters (like audiodev in the total > absence of audio) certainly makes less sense to me.=20 > >> Do we need a release note? >> >> Do we need an entry in docs/about/removed-features.rst? Feels a bit >> odd; we're not removing a feature, we're adding one, namely "can compile >> out audio". >> > > Maybe we should add something like, "If you compile out audio, be > careful with these things: [list of changes]".=20 > > But honestly, I don't know. I'd be happy to add whatever is needed. I guess a brief release note should suffice. As long as the affected interfaces are obviously audio-related, enumerating them seems unnecessary. >>> + (If audio is disabled at compile time via the ``--disable-audi= o`` option, >>> + no audio backend is used, and none of the audio-related D-Bus = interfaces >>> + are exported.) >>> [...] >> >> Well, audio is either compiled in or it isn't. >> >> If it's compiled in, then why tell the user how things behave when it's >> not? >> >> If it's not compiled in, then why document stuff that doesn't work? How >> much of -audiodev still works then? -audiodev none? Anything else? > > I agree it's weird, but I don't see a clear way around it. Simple > ifdef'ing isn't possible in a reStructuredText section (at least I > couldn't get it to work). Context: this is in an SRST...ERST section of qemu-options.hx. As far as I can tell, we simply ignore the possibility of the thing being compiled out when we document a thing there. Drop the patch hunk? >> [...]