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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id A286CC433EF for ; Wed, 23 Feb 2022 15:11:29 +0000 (UTC) Received: from localhost ([::1]:60812 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nMtId-0006yN-T5 for qemu-devel@archiver.kernel.org; Wed, 23 Feb 2022 10:11:27 -0500 Received: from eggs.gnu.org ([209.51.188.92]:33680) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nMtGM-0005md-2S for qemu-devel@nongnu.org; Wed, 23 Feb 2022 10:09:06 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:42521) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nMtGA-0003O7-14 for qemu-devel@nongnu.org; Wed, 23 Feb 2022 10:08:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1645628932; h=from:from:reply-to: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=h1Xtv2VJKLfP1DOvdMGVgIXh9U1GaLyR63us0IlG46I=; b=d8pqB/TgGKjIJHRktD5AO89XOxKC0zeMV2upf+9I9SWV4rwHbLpDUpeBgbjnllVAFegs4h 8K3CMsUlNwJRZoCR3XaxmjvAftFAV2+ZK/9xux2AyASsbc8RYvq3m0XAPTPHHz9Rz+YXZY eGex/BkVri22YU84BnJY/94P+48RlQ4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-112-dufXJlcYM_quGjWZDKFDyg-1; Wed, 23 Feb 2022 10:08:39 -0500 X-MC-Unique: dufXJlcYM_quGjWZDKFDyg-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 8D3DE1091DA0; Wed, 23 Feb 2022 15:08:38 +0000 (UTC) Received: from redhat.com (unknown [10.39.195.66]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4C165804D6; Wed, 23 Feb 2022 15:08:22 +0000 (UTC) Date: Wed, 23 Feb 2022 15:08:19 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: John Snow Subject: Re: [PATCH 0/5] qmp-shell modifications for non-interactive use Message-ID: References: <20220221155519.2367-1-damien.hedde@greensocs.com> <87bkyzzb1q.fsf@pond.sub.org> <3656609c-522d-a0e8-e6ef-465cdc9d6c88@greensocs.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.1.5 (2021-12-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Damien Hedde , Eduardo Habkost , Cleber Rosa , Markus Armbruster , qemu-devel Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Feb 23, 2022 at 10:01:05AM -0500, John Snow wrote: > On Wed, Feb 23, 2022 at 6:13 AM Daniel P. Berrangé wrote: > > > > On Wed, Feb 23, 2022 at 10:57:29AM +0100, Damien Hedde wrote: > > > > > > > > > On 2/22/22 11:31, Daniel P. Berrangé wrote: > > > > On Tue, Feb 22, 2022 at 10:38:09AM +0100, Damien Hedde wrote: > > > > > > > > > > > > > > > Here I just wanted to propose a simple way to just send a > > > > > bunch of commands from a source file and stop if something unexpected > > > > > happens. > > > > > Only goal is to be able to share a file on the ml and allow people to > > > > > reproduce easily. > > > > > We can already redirect the input, but it is almost impossible to see > > > > > if something failed. > > > > > > > > Yes, I see what you mean. So the problem with using 'socat' or similar > > > > is that we fill the input with commands and response appear asynchronously, > > > > so we can't match them up easily. This is actually a problem seen in the > > > > block I/O tests which just send QMP stuff in a batch. > > > > > > > > While you could do this by invoking socat once for each command, that > > > > gets silly with the repeated QMP handshake for each command. > > > > > > > > The thing about using qmp-shell is that it does a bunch of extra stuff > > > > targetted at humans on top, and history tells us it isn't a good idea > > > > to mix stuff for humans and machines in the same tool/interface. > > > > > > > > How about instead creating a separate 'qmp-send' command that is not > > > > much more than a "QMP-aware socat". By which I mean, it just reads > > > > raw QMP commands from stdin, sends each one to the server, but > > > > crucially waits for a reply after sending each, and stops on first > > > > error reponse. > > > > > > By 'qmp-send' command, you mean another script in scripts/qmp ? > > > Yes > > > > Yep. > > > > > If we go for another script, I would rather do one with wrap > > > feature (like your series) to start qemu as well. > > > > Sure, that would certainly make sense. I actually wanted to add > > the wrap feature directly into the existing qmp-shell, but it was > > not viable while maintaining back compat. With a new qmp-send > > command you can easily make "wrap mode" supported from the start. > > > > I'm also wary of adding scriptable interfaces to qmp-shell, but I can > see them having some value. > > I'm not against the ability to add some kind of "load commands from > file" interactive command to qmp-shell, for instance. (/LOAD or /PLAY > or something?) ... but then we need to worry about what the format of > the file is and how exactly that scripting language works. It's a > design minefield. My concern is that qmp-shell takes command input in a high level data format. I don't want to see that format turn into something that machines use, which is what is proposed initially here. For this reason I prefer to see a separate qmp-send that solves the automation problems, without introducing a new data format, just directly passing raw QMP messages to/fro. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|