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 X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 418BFC2D0DB for ; Mon, 27 Jan 2020 12:14:32 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0D422207FD for ; Mon, 27 Jan 2020 12:14:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="POpoMDI0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D422207FD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:43924 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iw3Hj-0005yg-4B for qemu-devel@archiver.kernel.org; Mon, 27 Jan 2020 07:14:31 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:33879) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iw3Go-0005Xc-7j for qemu-devel@nongnu.org; Mon, 27 Jan 2020 07:13:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iw3Gm-0000AI-JQ for qemu-devel@nongnu.org; Mon, 27 Jan 2020 07:13:33 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:24044 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iw3Gm-00008N-FY for qemu-devel@nongnu.org; Mon, 27 Jan 2020 07:13:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580127211; 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=O16HbfsbpLHeyzyUIZCVC0ywF3WKGaH4Qlzoq8QrBJQ=; b=POpoMDI08cobjvvdpE04fkGw0pRolEn8o6ef6zN+VOZ9sMq4zQKHEWi4JYC+GS+6WhC0wf aOTXEYvca7iZ1ErTJcS7wWqKjBXr+Nrsq0ijpsC/Ik4FZgvRL6SSwaz9zK8xHvuWDq2eB+ vuYSS4Aymbh1fUOxXJPD4zgitEhn4Zk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-86-RTEKPaSmPBaEFL5SSRMpFQ-1; Mon, 27 Jan 2020 07:13:29 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9D45F18FE882; Mon, 27 Jan 2020 12:13:27 +0000 (UTC) Received: from linux.fritz.box (ovpn-117-108.ams2.redhat.com [10.36.117.108]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6755A8889E; Mon, 27 Jan 2020 12:13:12 +0000 (UTC) Date: Mon, 27 Jan 2020 13:13:11 +0100 From: Kevin Wolf To: Gerd Hoffmann Subject: Re: Making QEMU easier for management tools and applications Message-ID: <20200127121311.GB5669@linux.fritz.box> References: <87h81unja8.fsf@dusky.pond.sub.org> <20191224134139.GD2710539@redhat.com> <30664f6e-81da-a6e6-9b20-037fc91290fb@redhat.com> <878slyej29.fsf@dusky.pond.sub.org> <20200123190145.GI657556@redhat.com> <2561a069-ce5f-3c30-b04e-db7cd2fcdc85@redhat.com> <871rrp474i.fsf@dusky.pond.sub.org> <20200127083513.hgl5ydgpn4mkuho5@sirius.home.kraxel.org> MIME-Version: 1.0 In-Reply-To: <20200127083513.hgl5ydgpn4mkuho5@sirius.home.kraxel.org> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: RTEKPaSmPBaEFL5SSRMpFQ-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , "Denis V. Lunev" , Cleber Rosa , Stefan Hajnoczi , Markus Armbruster , Eduardo Habkost , qemu-devel , Paolo Bonzini , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau , John Snow , Dominik Csapak Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 27.01.2020 um 09:35 hat Gerd Hoffmann geschrieben: > Hi, >=20 > > We build a "configuration" struct in QAPI, and extend from there. > >=20 > > (2) We offer "--config myconfig.yaml" as an option for specifying > > options. >=20 > Yes. >=20 > > This precludes the use of *any* traditional command line flags. >=20 > Hmm. Given that the transition effort will probably take a while > I think it makes sense to allow mixing config file and cmd line > switches, if it is only for testing the config file parsing and > processing. Maybe have a (temporary) -x-config for that? >=20 > We already have qapi schema for -blockdev + -display + -audiodev + > -chardev, creating a configuration struct which supports these > shouldn't be that much effort. Then move over QemuOpts one by one. chardev-add uses a QAPI type that has too deep nesting to be user friendly. Markus and I are trying to use mostly QAPIfied command line options for qemu-storage-daemon, and --chardev is one that we agree must be simplified to be bearable. > The most tricky part here probably is -device support. Possibly, though -object might not be much easier. > > - We WOULD need a new YAML parsing layer in QEMU, generated by QAPI. > > Supporting two deserialization layers could lead to strange > > discrepancies between the two formats at runtime. So, admittedly, using > > JSON would be *even easier*, as we could re-use the same parsers alread= y > > battle-tested in QEMU. We could get *MAXIMUM* code re-use this way. >=20 > Well, we can support multiple formats, much like openshift accepts both > json and yaml. json is pretty much there already, so we could start > with that and add yaml later on. Possibly even the ini-style syntax > accepted by -readconfig today, although I'm not sure there is much > benefit in that. >=20 > > - We will break compatibility with our existing CLI. People will not be > > happy about this, especially, perhaps, embedded board and TCG developer= s > > who use fairly minimal command lines regularly. >=20 > Once config file support is complete enough we should be able to offload > backward compatibility command line parsing to some script which > transforms the cli into a config file. Which is probably better than > trying to add -writeconfig to qemu as we don't have to do the string > processing in C then. If we get a launcher script anyway, I would argue that the system emulator binary written in C should only support JSON (like it already does) and the script can easily translate from YAML to JSON. Kevin