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 335E1C05027 for ; Thu, 9 Feb 2023 10:58:04 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pQ4cC-0003hD-H6; Thu, 09 Feb 2023 05:57:20 -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 1pQ4c7-0003gO-JU for qemu-devel@nongnu.org; Thu, 09 Feb 2023 05:57:15 -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 1pQ4c1-00050D-Q6 for qemu-devel@nongnu.org; Thu, 09 Feb 2023 05:57:15 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675940228; 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=0e+TZG+HQvhSK5upqLtRtbXe16CUD6PZTjWM4goZv+c=; b=dfOCc8H6s8pYIbuaQVHPkOjma18B3hgFq6ywZA6pCCo16yJM//gjzGWPXXnbQWAVSCMmCm 7NvIif3iweHcYUNNMw/9HG93SgCkrhI2H0DswDH3EH+ubmF40Er9usAkAwKywN+CzrOnnX ju4PcGq+MyBtled3TIVzhp70RoXKcoc= 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-439-lz8k5M2ZPQigz2vSATnn5w-1; Thu, 09 Feb 2023 05:57:02 -0500 X-MC-Unique: lz8k5M2ZPQigz2vSATnn5w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 13F141875044; Thu, 9 Feb 2023 10:57:02 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.101]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B092440398A0; Thu, 9 Feb 2023 10:57:01 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 4F2FB21E6A1F; Thu, 9 Feb 2023 11:57:00 +0100 (CET) From: Markus Armbruster To: Thomas Huth Cc: qemu-devel@nongnu.org, Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Peter Maydell , Paolo Bonzini , "Daniel P. Berrange" , Eduardo Habkost , =?utf-8?Q?C=C3=A9dric?= Le Goater , Mark Cave-Ayland , Mark Burton , Luc Michel , Bernhard Beschow , Bin Meng , Alistair Francis Subject: Re: Can we unpoison CONFIG_FOO macros? References: <87lel9o56z.fsf@pond.sub.org> <82627608-0daf-e8f6-c4a5-d8217cd538f5@redhat.com> Date: Thu, 09 Feb 2023 11:57:00 +0100 In-Reply-To: <82627608-0daf-e8f6-c4a5-d8217cd538f5@redhat.com> (Thomas Huth's message of "Tue, 7 Feb 2023 21:54:51 +0100") Message-ID: <87zg9n5coz.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 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 07/02/2023 16.39, Markus Armbruster wrote: >> We have a boatload of CONFIG_FOO macros that may only be used in >> target-dependent code. We use generated config-poison.h to enforce. >> This is a bit annoying in the QAPI schema. Let me demonstrate with an >> example: QMP commands query-rocker, query-rocker-ports, and so forth. >> These commands are useful only with "rocker" devices. They are >> compile-time optional. hw/net/Kconfig: >> config ROCKER >> bool >> default y if PCI_DEVICES >> depends on PCI && MSI_NONBROKEN >> The rocker device and QMP code is actually target-independent: >> hw/net/meson.build puts it into softmmu_ss. >> Disabling the "rocker" device type ideally disables the rocker QMP >> commands, too. Should be easy enough: 'if': 'CONFIG_FOO' in the QAPI >> schema. >> Except that makes the entire code QAPI generates for rocker.json >> device-dependent: it now contains #if defined(CONFIG_ROCKER), and >> CONFIG_ROCKER is poisoned. The rocker code implementing monitor >> commands also becomes device-dependent, because it includes generated >> headers. We compile all that per target for no sane reason at all. > > Well, CONFIG_ROCKER depends on the target config, so that is a sane reason in my eyes. Depending on which target you currently compile, it's either set or not set - there is no reasonable way to compile generic code and still test the CONFIG_ROCKER macro. > > So adding such a switch to rocker.json itself just cannot work. > > But at the "make" level, we distinguish between config-all-devices.mak and *-softmmu-config-devices.mak , so if you want to disable the rocker QMP code depending on whether CONFIG_ROCKER is set in *any* target binary or not, you would need a similar mechanism to config-all-devices.mak here, e.g. something that would switch the inclusion of rocker.json on or off depending on the switch in config-all-devices.mak ... > Would it be possible to add such a switch to qapi/meson.build ? > ... and to qapi/qapi-schema.json, I guess, since the rocker.json gets included from there? Something like that: > > diff --git a/qapi/meson.build b/qapi/meson.build > --- a/qapi/meson.build > +++ b/qapi/meson.build > @@ -59,9 +59,11 @@ if have_system > 'qdev', > 'pci', > 'rdma', > - 'rocker', > 'tpm', > ] > + if config_all_devices.has_key('CONFIG_ROCKER') > + qapi_all_modules += [ 'rocker', ] > + endif > endif > if have_system or have_tools > qapi_all_modules += [ > diff --git a/qapi/qapi-schema.json b/qapi/qapi-schema.json > --- a/qapi/qapi-schema.json > +++ b/qapi/qapi-schema.json > @@ -72,7 +72,7 @@ > { 'include': 'job.json' } > { 'include': 'net.json' } > { 'include': 'rdma.json' } > -{ 'include': 'rocker.json' } > +{ 'include': 'rocker.json', 'if': 'CONFIG_ROCKER' } > { 'include': 'tpm.json' } > { 'include': 'ui.json' } > { 'include': 'authz.json' } > > No clue whether the qapi parser could be extended like that, though... Feels feasible. I had vague ideas going this direction, too. Thanks for fleshing them out for me! Hmm, we have somewhat hairy code in qapi/meson.build to enumerate the QAPI modules and generated source files, and to add them to the right source sets. Perhaps we could have qapi-gen generate some of that.