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 02BC5C4345F for ; Mon, 29 Apr 2024 16:03:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1s1TMZ-0004xq-4f; Mon, 29 Apr 2024 11:56:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1s1TMK-0004aI-02 for qemu-devel@nongnu.org; Mon, 29 Apr 2024 11:56:04 -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 1s1TMH-0005Ky-GE for qemu-devel@nongnu.org; Mon, 29 Apr 2024 11:56:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1714406160; 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=4AAnRuWD8C2GDGP/Dxv3MHFn8zZkGRM+IwEpQYlOX34=; b=Ib794IX9wI3c6wR7bdG+1ffIta7hiUTJd2YJbHjpCTHLJ4pF5txPkPKohUnfPjMrPMra7x exMe+eN23rbPBTFtTSBJ2Lf6du3NVfW5zP6hSopZ4Sujw72lSwxbhKjm3CVcCDnDouWzs2 rZ+gszVPO6HuCe5twl8X6/Apy+4WN4I= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-220-JCuZKY-OPKOmICWwWkKEOQ-1; Mon, 29 Apr 2024 11:55:55 -0400 X-MC-Unique: JCuZKY-OPKOmICWwWkKEOQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6E5C21C0C653; Mon, 29 Apr 2024 15:55:53 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.132]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 83BD51C060D1; Mon, 29 Apr 2024 15:55:45 +0000 (UTC) Date: Mon, 29 Apr 2024 16:55:43 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Cc: QEMU Developers , Daniil Tatianin , armbru@redhat.com, Alex =?utf-8?Q?Benn=C3=A9e?= , afaerber@suse.de, ale@rev.ng, alistair.francis@wdc.com, Anton Johansson , bbauman@redhat.com, bcain@quicinc.com, Chao Peng , cjia@nvidia.com, clg@kaod.org, cw@f00f.org, Damien Hedde , eblake@redhat.com, edgar.iglesias@gmail.com, eduardo@habkost.net, Elena Ufimtseva , eric.auger@redhat.com, felipe@nutanix.com, iggy@theiggy.com, imp@bsdimp.com, jan.kiszka@web.de, jgg@nvidia.com, jidong.xiao@gmail.com, jim.shu@sifive.com, jjherne@linux.vnet.ibm.com, Joao Martins , konrad.wilk@oracle.com, Luc Michel , mburton@qti.qualcomm.com, mdean@redhat.com, mimu@linux.vnet.ibm.com, paul.walmsley@sifive.com, pbonzini@redhat.com, Peter Maydell , Richard Henderson , Shameerali Kolothum Thodi , shentey@gmail.com, stefanha@gmail.com, wei.w.wang@intel.com, z.huo@139.com, LIU Zhiwei , zwu.kernel@gmail.com, eblot@rivosinc.com, max.chou@sifive.com Subject: Re: QEMU Community Call Agenda Items (April 30th, 2024) Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 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: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.987, 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, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Apr 29, 2024 at 05:06:36PM +0200, Philippe Mathieu-Daudé wrote: > Hi, > > On 29/4/24 00:25, Philippe Mathieu-Daudé wrote: > > Hi, > > > > The KVM/QEMU community call is at: > > > >   https://meet.jit.si/kvmcallmeeting > >   @ > >   30/4/2024 14:00 UTC > > > > Are there any agenda items for the sync-up? > > I'd like to discuss two issues: > > 1/ Stability of QOM path > --------------------- > > Currently we have 3 QOM containers: > - /machine > QOM objects properly parented go there > - /machine/unattached > Orphan QOM objects. Missing parent is usually easy > to figure out, but we need to post patches to fix them. > - /machine/peripheral[-anon] > Devices created at runtime with CLI -device or QAPI device_add. > (-anon is for devices with no explicit bus ID). > See "Problem 4: The /machine/unattached/ orphanage" in [1]. > > The /machine and /machine/unattached trees are stable, although > by adding parent to orphan objects, their path will change. > > Objects in /machine/peripheral[-anon] depend on the order of > the device_add commands / arguments used. > > In a dynamically created machine, everything depend on how the > device_add commands are processed. > > How can be expect to easily reference a QOM object by its path? FYI, for reference libvirt uses a couple of QOM paths * "/machine/unattached/device[0]" - path of first vCPU, but this is an historical artifact - nowdays we query the paths from query-cpus-fast * "/machine/peripheral/%s/virtio-backend" where '%s' is the ID we give the virtio device, for virtio-blk disks * /machine/peripheral/%s/%s.0/legacy[0] where both '%s' are the ID we give the USB defvice, for USB disks * /machine/peripheral when enumerating devices we've assigned ID aliases to. * /machine to get the rtc-time property value > 2/ Is it safe to broadcast a QAPI event to all type of device/object? > ------------------------------------------------------------------ > > We have QMP commands such @rtc-reset-reinjection or @inject-nmi > which expect a single RTC / NMI listener in the machine. > > When using heterogeneous machines, we might end with multiple RTC > or NMI-aware devices. Should these commands be broadcasted to all > devices, or should we explicitly pass a list of paths to devices > we want to notify. Maybe we want both options. > > See threads around NMI [2] and RTC [3]. > > [1] https://lore.kernel.org/qemu-devel/87o7d1i7ky.fsf@pond.sub.org/ > [2] https://lore.kernel.org/qemu-devel/f4a6492b-cff4-439d-8f34-cdf04cb747ee@redhat.com/ > [3] https://lore.kernel.org/qemu-devel/20240425133745.464091-1-d-tatianin@yandex-team.ru/ > > Regards, > > Phil. > With 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 :|