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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7DEE7C33CB2 for ; Fri, 31 Jan 2020 09:51:35 +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 462F8206F0 for ; Fri, 31 Jan 2020 09:51:35 +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="ABGVqXJF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 462F8206F0 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]:50754 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixSxa-0004om-HC for qemu-devel@archiver.kernel.org; Fri, 31 Jan 2020 04:51:34 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41330) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ixSwi-0003zv-Bq for qemu-devel@nongnu.org; Fri, 31 Jan 2020 04:50:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ixSwh-0007SC-2X for qemu-devel@nongnu.org; Fri, 31 Jan 2020 04:50:40 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:21508 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ixSwf-0007Nj-8S for qemu-devel@nongnu.org; Fri, 31 Jan 2020 04:50:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580464236; 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=pJRbZSnGgMpMjyGCPpCU1a7QxDRPSRHuwSY/lQCwQYc=; b=ABGVqXJF8CfwuKAdZ+cc/MyMo8RxVG+Fq5SMqCj7oescVZI4OgS4aRIUbR83Re2dGa6vWY C+nkBrz1IsjtnxPbM1GYClbwmsCjWI1vY+07erc1ItgGmk/5aKlYCgZbFkT6YAi93sHvUC PIS+tvbVb4iL3idpVMOe8goVoWWtWj4= 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-252-6mPNMvBJMVe_VDi-7_v85w-1; Fri, 31 Jan 2020 04:50:33 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A78DE800D5A; Fri, 31 Jan 2020 09:50:32 +0000 (UTC) Received: from paraplu.localdomain (ovpn-117-252.ams2.redhat.com [10.36.117.252]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DCA685C290; Fri, 31 Jan 2020 09:50:24 +0000 (UTC) Received: by paraplu.localdomain (Postfix, from userid 1001) id 695CB3E04B8; Fri, 31 Jan 2020 10:50:23 +0100 (CET) Date: Fri, 31 Jan 2020 10:50:23 +0100 From: Kashyap Chamarthy To: Markus Armbruster Subject: Re: Improving QOM documentation [Was: Re: Making QEMU easier for management tools and applications] Message-ID: <20200131095023.GA9328@paraplu> References: <20200108133842.GE5057@dhcp-200-226.str.redhat.com> <87d0bmchq0.fsf@dusky.pond.sub.org> <1B253197-5592-472A-AA26-E0614A13C91A@redhat.com> <87o8v52hz9.fsf@dusky.pond.sub.org> <8CF8359B-1E52-4F7A-944E-C1C14FEC4F92@redhat.com> <87r200zzje.fsf@dusky.pond.sub.org> <20200115121953.GJ93923@redhat.com> <874kwwvmuv.fsf@dusky.pond.sub.org> <20200130210902.GA25927@paraplu> <87y2toi29o.fsf@dusky.pond.sub.org> MIME-Version: 1.0 In-Reply-To: <87y2toi29o.fsf@dusky.pond.sub.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-MC-Unique: 6mPNMvBJMVe_VDi-7_v85w-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: 205.139.110.120 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: Kevin Wolf , Peter Maydell , Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , "Denis V. Lunev" , Stefan Hajnoczi , qemu-devel , Paolo Bonzini , Christophe de Dinechin , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau , Dominik Csapak , John Snow , ehabkost@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Jan 31, 2020 at 07:11:15AM +0100, Markus Armbruster wrote: > Kashyap Chamarthy writes: [...] > > What can be done to improve QOM documentation (or lack thereof)? >=20 > Are you trying to push us from idle grousing to actually improve things? > No fair! I first wrote it as a semi-complaint, and then I caught myself: "you're not helping"; so I rephrased it to be more constructive. :-) > > From a couple of hurried `grep` queries in the QEMU tree, there seems t= o > > be no explicit qom.rst|txt, or qemu-object-model.txt|rst or some such. > > (I hope I haven't missed any other files.) >=20 > As far as I know, all we have is the lovingly[*] written comments in > include/qom/object.h. Sadly, we've let them rot in places. In > particular, many newer functions are undocumented. >=20 > This is *reference* documentation. What we lack (sorely!) is an > overview / friendly introduction, and a design document with rationale. > Reconstructing rationale now would involve guesswork. Me nods; that (guesswork in retroactive rationale construction) makes matters slightly more difficult. [...] > > Opening qom/object.h[2], indeed there is copious amounts of docs, > > expressed as commented-out text. Two questions: > > > > - How much of this is still accurate? (Sorry, if that's a loaded > > question.) >=20 > May I present you Armbru's Comment Trust Levels: > > ACTL2: The comment may be overly terse or incomplete, but the > probability for it to be outright wrong is low. >=20 > ACTL1: Treat as helpful guidance (with gratitude), but trust only the > code. >=20 > ACTL0: It is a tale Told by an idiot[**], full of sound and fury, > Signifying nothing. >=20 > Most comments in decently maintained code are at ACTL1. Noted. (And thanks for the useful reference scale :-)) > Around the time initial QOM development solidified, object.h's comments > were ACTL2. The neglect that is now clearly visible there makes me > downgrade to ACTL1. >=20 > Paolo will have a more informed and possibly different opinion. >=20 > > - If at least 60% is still accurate, is it valuable to extract and > > publish it as rendered rST, as part of the on-going QEMU Docs > > improvement? >=20 > Beware, personal opinion. >=20 > When you put documentation next to the code it documents (which you > absolutely should, because it's your only realistic chance to keep the > two in sync), then extracting API comments is useful, because it > collects them in one place. >=20 > It's of next to no use to me when the comments are all in the same place > already, namely the header. Yeah, reasonable point. > > (b) The other clue is also from the same post, where Eduardo provides > > pointers to past KVM Forum presentations by MarkusA, PaoloB, > > AndreasF on QOM, Qdev et al. > > > > Is it worth slapping all these references (with a clear intro and > > outro) into a qom.rst file in QEMU tree, even if only for > > reference/context? Or are these references, in-tree docs in > > object.h out-of-date beyond repair? =20 >=20 > Uff. >=20 > My qdev talks predate the rebase onto QOM. They may well confuse / > mislead as much as inform now. Good to know. (We don't want to add additional sources of confusion.) > > If it is useful, I'm happy to get the initial doc going, secure in the > > knowledge that more clueful people than me will chip in during the > > review :-) >=20 > Ha, nerd sniping! :-) Thanks for the response; it was useful. [...] --=20 /kashyap