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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC092C433F5 for ; Mon, 25 Oct 2021 12:14:31 +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 A0D9A60F70 for ; Mon, 25 Oct 2021 12:14:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A0D9A60F70 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:52978 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1meys2-0006LW-2v for qemu-devel@archiver.kernel.org; Mon, 25 Oct 2021 08:14:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47742) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1meyjX-00080Z-Mq for qemu-devel@nongnu.org; Mon, 25 Oct 2021 08:05:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:30429) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1meyjP-0003Nt-Vv for qemu-devel@nongnu.org; Mon, 25 Oct 2021 08:05:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635163535; 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=cvd4zOfuhKi6S01Z5kiuGq4BEoxK1dU5DsITiAiBL+o=; b=Ti9mlJACaIue0jVhk/OqdVWe7qzxIg+t2/E2hyyXCAt2qz1KQZia8WzCrYzyk0cOb57G7m Mcjjqu0m1zCa6FQWMWyKaKshQ1q0oGM3p4CFQ8b1eZQEUZGND+E6WaAegrwhRSgj2w4a91 pxhMFNV/77u300ss56ltISz1/+Ifdao= 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-444-RZlQAuUQOSaFwFErWqykuA-1; Mon, 25 Oct 2021 08:05:32 -0400 X-MC-Unique: RZlQAuUQOSaFwFErWqykuA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F2823101F7A9; Mon, 25 Oct 2021 12:05:30 +0000 (UTC) Received: from paraplu (unknown [10.39.194.107]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7D4BF1835D; Mon, 25 Oct 2021 12:05:03 +0000 (UTC) Date: Mon, 25 Oct 2021 14:05:00 +0200 From: Kashyap Chamarthy To: Markus Armbruster Subject: Re: [PATCH 1/9] qapi: New special feature flag "unstable" Message-ID: References: <20211025052532.3859634-1-armbru@redhat.com> <20211025052532.3859634-2-armbru@redhat.com> MIME-Version: 1.0 In-Reply-To: <20211025052532.3859634-2-armbru@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kchamart@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=kchamart@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -8 X-Spam_score: -0.9 X-Spam_bar: / X-Spam_report: (-0.9 / 5.0 requ) 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_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action 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: kwolf@redhat.com, pkrempa@redhat.com, berrange@redhat.com, ehabkost@redhat.com, qemu-block@nongnu.org, quintela@redhat.com, libvir-list@redhat.com, qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com, libguestfs@redhat.com, marcandre.lureau@redhat.com, pbonzini@redhat.com, eblake@redhat.com, dgilbert@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Oct 25, 2021 at 07:25:24AM +0200, Markus Armbruster wrote: > By convention, names starting with "x-" are experimental. The parts > of external interfaces so named may be withdrawn or changed > incompatibly in future releases. > > Drawback: promoting something from experimental to stable involves a > name change. Client code needs to be updated. > > Moreover, the convention is not universally observed: > > * QOM type "input-barrier" has properties "x-origin", "y-origin". > Looks accidental, but it's ABI since 4.2. > > * QOM types "memory-backend-file", "memory-backend-memfd", > "memory-backend-ram", and "memory-backend-epc" have a property > "x-use-canonical-path-for-ramblock-id" that is documented to be > stable despite its name. Looks like there's another stable property with an "x-" prefix: "x-remote-object", part of QOM type @RemoteObjectProperties. Given the above "x-" properties are now stable, I take it that they cannot be renamed now, as they might break any tools using them? My guess is the tedious way is not worth it: deprecate them, and add the non-x variants as "synonyms". > We could document these exceptions, but documentation helps only > humans. We want to recognize "unstable" in code, like "deprecated". > > Replace the convention by a new special feature flag "unstable". It > will be recognized by the QAPI generator, like the existing feature > flag "deprecated", and unlike regular feature flags. FWIW, sounds good to me. > This commit updates documentation and prepares tests. The next commit > updates the QAPI schema. The remaining patches update the QAPI > generator and wire up -compat policy checking. > > Signed-off-by: Markus Armbruster > --- > docs/devel/qapi-code-gen.rst | 9 ++++++--- > tests/qapi-schema/qapi-schema-test.json | 7 +++++-- > tests/qapi-schema/qapi-schema-test.out | 5 +++++ > 3 files changed, 16 insertions(+), 5 deletions(-) [...] -- /kashyap