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 13AAFCD98F2 for ; Tue, 23 Jun 2026 11:53:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wbzgr-0002HZ-AS; Tue, 23 Jun 2026 07:53:17 -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 1wbzgq-0002HR-EQ for qemu-devel@nongnu.org; Tue, 23 Jun 2026 07:53:16 -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 1wbzgo-0004Ep-G0 for qemu-devel@nongnu.org; Tue, 23 Jun 2026 07:53:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1782215591; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Qy0aCBUTQzhck0MsAuaeR0PU8PFm4pRs6GlFCH0MmZ8=; b=Xphk1XvS9/zLlBi84d+1mJiHZzyLPoAj1iBOYrQnGkdOZNxUUim0vHY5Oj7L8dHvSgvqIW vrk7ZslrUg/ZaMHsE54pBviLIZHzp2zsE47h4Lm6uvmgcHqzUvFHIWJqX8q8nj1bbWdJIo n3Cted+wZlvu99AOGGoulmtpd2a1YkU= Received: from mx-prod-mc-01.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-106-p01KKbtMPDWUXUlDiKbHKg-1; Tue, 23 Jun 2026 07:53:05 -0400 X-MC-Unique: p01KKbtMPDWUXUlDiKbHKg-1 X-Mimecast-MFC-AGG-ID: p01KKbtMPDWUXUlDiKbHKg_1782215582 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-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7BF411955F27; Tue, 23 Jun 2026 11:53:01 +0000 (UTC) Received: from redhat.com (unknown [10.44.34.133]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7B6D81800591; Tue, 23 Jun 2026 11:52:57 +0000 (UTC) Date: Tue, 23 Jun 2026 12:52:53 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Peter Krempa , qemu-devel@nongnu.org, "Dr. David Alan Gilbert" , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Christian Brauner , devel@lists.libvirt.org, Markus Armbruster , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Paolo Bonzini , Alex =?utf-8?Q?Benn=C3=A9e?= Subject: Re: [PATCH v4 00/35] monitor: turn QMP and HMP into QOM objects Message-ID: References: <20260623095551.2106712-1-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: 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_H5=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 Tue, Jun 23, 2026 at 12:38:10PM +0100, Daniel P. Berrangé wrote: > On Tue, Jun 23, 2026 at 01:03:46PM +0200, Peter Krempa wrote: > > On Tue, Jun 23, 2026 at 10:55:16 +0100, Daniel P. Berrangé via Devel wrote: > > > 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 > > > > I was giving this a spin by implementing libvirt support for it. The > > basic usage seems to work well but I've encoutered a regression in > > behaviour which happens both when the QMP monitor is instantiated using > > the new syntax but also the old one > > ( -mon chardev=charmonitor,id=monitor,mode=control) > > > > When libvirt wants to re-connect to a qemu running with these patches it > > re-issues a 'qmp_capabilities' command after connecting. > > > > With these patches qemu does not respond to that command even when the > > old syntax is used. This makes libvirt stuck when re-connecting to VMs. > > Oh that's odd, thanks for the warning. I'll investigate this. /face-palm - a misplaced a line in the auto-delete code, and did not have test coverage of re-opening a monitor. Try testing libvirt with this additional change on top diff --git a/monitor/qmp.c b/monitor/qmp.c index f6b7fe65bb..10d651ca5c 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -613,7 +613,6 @@ static void monitor_qmp_event(void *opaque, QEMUChrEvent event) qobject_unref(data); break; case CHR_EVENT_CLOSED: - mon->delete_pending = true; /* * Note: this is only useful when the output of the chardev * backend is still open. For example, when the backend is @@ -629,6 +628,7 @@ static void monitor_qmp_event(void *opaque, QEMUChrEvent event) case MONITOR_QMP_CLOSE_ACTION_NONE: break; /* nada */ case MONITOR_QMP_CLOSE_ACTION_DELETE: + mon->delete_pending = true; /* * Do NOT run in the AIO context associated with the * monitor. We need to run in the default AIO context 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 :|