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 lists1p.gnu.org (lists1p.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 18035C43458 for ; Wed, 1 Jul 2026 13:46:57 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wevH2-0006Ab-Fc; Wed, 01 Jul 2026 09:46:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wevH1-0006AQ-45 for qemu-devel@nongnu.org; Wed, 01 Jul 2026 09:46:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wevGz-0007dO-C4 for qemu-devel@nongnu.org; Wed, 01 Jul 2026 09:46:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1782913600; 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=auohRCKWWACf8rRt+/wnNjayZU1Vlic1YoDPcquU/4Y=; b=dQxWwRThcrsN8MNuaLG/iWQh58wZsmmh+egFFGtHuJWvnElZxU/5SbaiLXe3jByEKKdajQ z+W2BZrbnl5PdrSsmaf5yqmHGZ3rntlHu/Rk4yJue7PX8zwGCqFwZx+weBnbdLzTTUsY/Y ImYP+unleYV3YQu2FFVt5DixULXQ3LM= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-116-W0zH4Q5oOemPI6D5ay-fVQ-1; Wed, 01 Jul 2026 09:46:36 -0400 X-MC-Unique: W0zH4Q5oOemPI6D5ay-fVQ-1 X-Mimecast-MFC-AGG-ID: W0zH4Q5oOemPI6D5ay-fVQ_1782913595 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4A4B41933F8F; Wed, 1 Jul 2026 13:46:35 +0000 (UTC) Received: from redhat.com (unknown [10.44.33.35]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D453E18007E7; Wed, 1 Jul 2026 13:46:31 +0000 (UTC) Date: Wed, 1 Jul 2026 14:46:28 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Markus Armbruster Cc: qemu-devel@nongnu.org, devel@lists.libvirt.org, =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Paolo Bonzini , "Dr. David Alan Gilbert" , Alex =?utf-8?Q?Benn=C3=A9e?= , Christian Brauner , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: [PATCH v5 00/35] monitor: turn QMP and HMP into QOM objects Message-ID: References: <20260624173752.2928717-1-berrange@redhat.com> <87fr236t9v.fsf@pond.sub.org> <87ik6y4yk9.fsf@pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87ik6y4yk9.fsf@pond.sub.org> User-Agent: Mutt/2.3.2 (2026-04-26) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 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: 8 X-Spam_score: 0.8 X-Spam_bar: / X-Spam_report: (0.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Jul 01, 2026 at 03:41:26PM +0200, Markus Armbruster wrote: > Daniel P. Berrangé writes: > > > On Wed, Jul 01, 2026 at 09:52:44AM +0200, Markus Armbruster wrote: > >> Daniel P. Berrangé writes: > >> > >> > Conceptually -object and object_add/object_del should be sufficient > >> > for essentially all QEMU configuration....if only we ported all our > >> > internal custom backends/devices/etc to QOM. That is of course a big > >> > job which is why it hasn't happened. > >> > > >> > This series started with the premise that the monitor is one of the > >> > easier areas to convert since we have no more than three classes, > >> > a common base, and QMP and HMP subclasses[1]. So why not give it a > >> > go and thus unlock the ability to dynamically create/delete monitors > >> > in QMP/HMP. > >> > > >> > This series does the conversion in a great many small steps to better > >> > understand the implications at each stage. > >> > > >> > The high level outcome of this series is > >> > > >> > * HMP and QMP monitors are QOM objects, 'monitor-hmp' and > >> > 'monitor-qmp' respectively > >> > > >> > * Both can be cold plugged and hot plugged. QMP only, can > >> > also be hot unplugged. > >> > > >> > * '-mon' is obsolete, deprecated and replaced by '-object', > >> > but -monitor, -qmp and kept as high level syntax sugar > >> > >> Possible additional work: change monitor_parse() to build a > >> MonitorOptions instead of a QemuOpts, so it call monitor_new() directly > >> instead of via monitor_new_opts(). Observation, not a demand. > >> > >> > > >> > * QMP gains a concept of "close-action" which makes it > >> > possible to mark a monitor for auto-delete. > >> > >> I'm not quite convinced this is warranted. I'd like to hear more about > >> use cases. > > > > Replied about that inline to the patch. IMHO without this facility > > the series does not fully address the needs of systemd that motivated > > the original patches: > > > > https://lists.nongnu.org/archive/html/qemu-devel/2026-04/msg01349.html > > > >> Is libvirt going to make use of it? > > > > This wasn't motivated by libvirt's needs, but indeed it could be > > useful for libvirt. Currently if apps want to access QMP, they > > need to use libvirt's QMP passthrough, which means they need > > special client code to talk to libvirt APIs. > > > > With this libvirt could dynamically add a monitor, with auto > > close, open it and pass the open FD back to the client app. > > libvirt would not need to watch for when the client app is > > gone as dropping the FD would cleanup the monitor. > > Alright, that's fair. The management application doesn't spawn > something that wants a dedicated monitor, it makes one for a client. > > Would this fit into a commit message somewhere? Sure, it fits in the commit message for the auto-delete patch. With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|