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 E6BBFC2D0B1 for ; Thu, 6 Feb 2020 12:13:09 +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 B24EC20730 for ; Thu, 6 Feb 2020 12:13:09 +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="EeKgtOow" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B24EC20730 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]:37586 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1izg1s-0003SN-U1 for qemu-devel@archiver.kernel.org; Thu, 06 Feb 2020 07:13:08 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:60341) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1izg11-0002rH-QE for qemu-devel@nongnu.org; Thu, 06 Feb 2020 07:12:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1izg10-0004zc-Ih for qemu-devel@nongnu.org; Thu, 06 Feb 2020 07:12:15 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:49868 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 1izg10-0004ym-F2 for qemu-devel@nongnu.org; Thu, 06 Feb 2020 07:12:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580991131; 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=d4it+xLNcJYbLr3TPv8GWLwY4E9TsajHVAhH6suzjrI=; b=EeKgtOowlQvwDJARfs59KINdrKPkjkT67/PnaL5tGiyxZt+RbtyQhsVoqiiRqFpJLqr5o/ xueuQkmJVgq3WY5kflW64NZvONDpG2YrR8m0TraEvMzRHO9NzwCSi4nodOa4frQ8+hHWeb iJbo9Bb0kAavG2ClTsjDtIjrVujlPOY= 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-13-IZo9p3uhM3a3dj2t9zLLcA-1; Thu, 06 Feb 2020 07:12:10 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D6FA4DB63; Thu, 6 Feb 2020 12:12:08 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-136.ams2.redhat.com [10.36.116.136]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 671C3790C8; Thu, 6 Feb 2020 12:12:00 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id ED3C111386A7; Thu, 6 Feb 2020 13:11:58 +0100 (CET) From: Markus Armbruster To: Daniel P. =?utf-8?Q?Berrang=C3=A9?= Subject: Re: qmp-shell for GSoC/Outreachy? References: <20200123190145.GI657556@redhat.com> <2561a069-ce5f-3c30-b04e-db7cd2fcdc85@redhat.com> <20200124095027.GA824327@redhat.com> <20200127143505.GD5669@linux.fritz.box> <20200127202925.GE3419@work-vm> <20200128105932.GC6431@linux.fritz.box> <20200205130946.GC5768@dhcp-200-226.str.redhat.com> <20200205194944.GP3210@work-vm> <877e10xdd6.fsf@dusky.pond.sub.org> <20200206100920.GD2391707@redhat.com> Date: Thu, 06 Feb 2020 13:11:58 +0100 In-Reply-To: <20200206100920.GD2391707@redhat.com> ("Daniel P. =?utf-8?Q?B?= =?utf-8?Q?errang=C3=A9=22's?= message of "Thu, 6 Feb 2020 10:09:20 +0000") Message-ID: <8736bnx6cx.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-MC-Unique: IZo9p3uhM3a3dj2t9zLLcA-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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 , "Denis V. Lunev" , Cleber Rosa , Stefan Hajnoczi , "Dr. David Alan Gilbert" , Eduardo Habkost , qemu-devel , Paolo Bonzini , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , John Snow , Dominik Csapak Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Daniel P. Berrang=C3=A9 writes: > On Thu, Feb 06, 2020 at 10:40:37AM +0100, Markus Armbruster wrote: >> > If the user screwsup, it should give an error that prompts the user >> > to the parameter they got wrong. >> > >> > Output from commands should normally be pretty formatted (with an opti= on >> > to display raw json for those needing it). >> > e.g. that 'query-version' should give either just the package >> > version (as info version currently does) or: >> > 4.2.50 Package: v4.2.0-1188-gd95a3885a9 >> > >> > We shouldn't lose any HMP commands that some people find useful >> > Ditching HMP isn't an option until we've got almost all of it >> > covered. >>=20 >> In particular, we currently use HMP for debugging and monitoring >> purposes, where we don't need or want QMP's rigor, neither its rigorous >> interface stability, nor its structured I/O. We want the "whipuptitude" >> we get from monitor_printf(). This is actually a point David has made >> several times. > > I'd like to argue that this decision to keep these debugging/monitoring > things in HMP only was a mistake, because it ensures that QEMU internals > need to keep HMP related code forever. > > What we actually need is a part of QMP that does not have the long term > stability requirement, nor need for fully structured data. In fact this > pretty much already exists - we have declared the 'x-' prefix as a way > to model QMP commands which are experimental / suboptimal / subject > to change. > > I suggest that every HMP command which does not have a QMP equivalent > should be turned into a QMP command with an "x-" prefix, with no > extra modelling applied Makes sense (see my point about "allowing some [whipuptitude] in QMP"), except I disagree with your example: > Take "info block" > > (hmp) info block > ide1-cd0: [not inserted] > Attached to: /machine/unattached/device[23] > Removable device: not locked, tray closed > > floppy0: [not inserted] > Attached to: /machine/unattached/device[16] > Removable device: not locked, tray closed > > sd0: [not inserted] > Removable device: not locked, tray closed > > > I suggest we support it as "x-query-block" > > (qmp) x-query-block > { > "return": { > "info": "ide1-cd0: [not inserted] > Attached to: /machine/unattached/device[23] > Removable device: not locked, tray closed > > floppy0: [not inserted] > Attached to: /machine/unattached/device[16] > Removable device: not locked, tray closed > > sd0: [not inserted] > Removable device: not locked, tray closed" > } > } This commmand does have a QMP equivalent: query-block. Hmm, no more. It actually wraps around both query-block and query-named-block-nodes now. I think that makes it an example of "go beyond 1:1". A better example for "allowing whipuptitude" would be "info registers". > Functionally we in fact already support pretty much exactly > that via the "human-monitor-command" QMP command. > > The difference is that with the latter, we will still have to > keep around the internal dispatching machinery for HMP inside > QEMU forever. If we transplant all remaining HMP commands with > an "x-" prefix, we open up the possibility of completely > separating HMP out and having QEMU work exclusively with QMP > internally. > > This is complementary to an improved qmp-shell client. Yes.