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=-0.8 required=3.0 tests=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 336B2C3A59D for ; Thu, 15 Aug 2019 14:45:05 +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 0BCA620644 for ; Thu, 15 Aug 2019 14:45:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0BCA620644 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]:42646 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyGzv-0006tI-C9 for qemu-devel@archiver.kernel.org; Thu, 15 Aug 2019 10:45:03 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58194) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hyGzI-0006Qd-1Q for qemu-devel@nongnu.org; Thu, 15 Aug 2019 10:44:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hyGzF-0004vt-Mj for qemu-devel@nongnu.org; Thu, 15 Aug 2019 10:44:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57326) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hyGz9-0004p6-R9; Thu, 15 Aug 2019 10:44:16 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E08A93086272; Thu, 15 Aug 2019 14:44:14 +0000 (UTC) Received: from dhcp-4-67.tlv.redhat.com (dhcp-4-67.tlv.redhat.com [10.35.4.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1EC2C95A50; Thu, 15 Aug 2019 14:44:09 +0000 (UTC) Message-ID: <2561ace5297c93cee597c776230dcb8f457a8561.camel@redhat.com> From: Maxim Levitsky To: Markus Armbruster , Kevin Wolf Date: Thu, 15 Aug 2019 17:44:09 +0300 In-Reply-To: <87y2zuy0k7.fsf@dusky.pond.sub.org> References: <20190814202219.1870-1-mlevitsk@redhat.com> <20190815091039.GA7415@linux.fritz.box> <87y2zuy0k7.fsf@dusky.pond.sub.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Thu, 15 Aug 2019 14:44:14 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 00/13] RFC: luks/encrypted qcow2 key management 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: Fam Zheng , Daniel =?ISO-8859-1?Q?P=2EBerrang=E9?= , qemu-block@nongnu.org, qemu-devel@nongnu.org, Max Reitz , Stefan Hajnoczi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 2019-08-15 at 16:18 +0200, Markus Armbruster wrote: > Kevin Wolf writes: > > > Am 14.08.2019 um 23:08 hat Eric Blake geschrieben: > > > On 8/14/19 3:22 PM, Maxim Levitsky wrote: > > > > > > > This is an issue that was raised today on IRC with Kevin Wolf. Really thanks > > > > for the idea! > > > > > > > > We agreed that this new qmp interface should take the same options as > > > > blockdev-create does, however since we want to be able to edit the encryption > > > > slots separately, this implies that we sort of need to allow this on creation > > > > time as well. > > > > > > > > Also the BlockdevCreateOptions is a union, which is specialized by the driver name > > > > which is great for creation, but for update, the driver name is already known, > > > > and thus the user should not be forced to pass it again. > > > > However qmp doesn't seem to support union type guessing based on actual fields > > > > given (this might not be desired either), which complicates this somewhat. > > > > > > Does the idea of a union type with a default value for the discriminator > > > help? Maybe we have a discriminator which defaults to 'auto', and add a > > > union branch 'auto':'any'. During creation, if the "driver":"auto" > > > branch is selected (usually implicitly by omitting "driver", but also > > > possible explicitly), the creation attempt is rejected as invalid > > > regardless of the contents of the remaining 'any'. But during amend > > > usage, if the 'auto' branch is selected, we then add in the proper > > > "driver":"xyz" and reparse the QAPI object to determine if the remaining > > > fields in 'any' still meet the specification for the required driver branch. > > > > > > This idea may still require some tweaks to the QAPI generator, but it's > > > the best I can come up with for a way to parse an arbitrary JSON object > > > with unknown validation, then reparse it again after adding more > > > information that would constrain the parse differently. > > > > Feels like this would be a lot of code just to allow the client to omit > > passing a value that it knows anyway. If this were a human interface, I > > could understand the desire to make commands less verbose, but for QMP I > > honestly don't see the point when it's not trivial. > > Seconded. But what about my suggestion of adding something like: { 'union': 'BlockdevAmendOptions', 'base': { 'node-name': 'str' }, 'discriminator': { 'get_block_driver(node-name)' } , 'data': { 'file': 'BlockdevCreateOptionsFile', 'gluster': 'BlockdevCreateOptionsGluster', 'luks': 'BlockdevCreateOptionsLUKS', 'nfs': 'BlockdevCreateOptionsNfs', 'parallels': 'BlockdevCreateOptionsParallels', 'qcow': 'BlockdevCreateOptionsQcow', 'qcow2': 'BlockdevCreateOptionsQcow2', 'qed': 'BlockdevCreateOptionsQed', 'rbd': 'BlockdevCreateOptionsRbd', 'sheepdog': 'BlockdevCreateOptionsSheepdog', 'ssh': 'BlockdevCreateOptionsSsh', 'vdi': 'BlockdevCreateOptionsVdi', 'vhdx': 'BlockdevCreateOptionsVhdx', 'vmdk': 'BlockdevCreateOptionsVmdk', 'vpc': 'BlockdevCreateOptionsVpc' } } This shouldn't be hard to do IMHO. Best regards, Maxim Levitsky