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 D50ADC433F5 for ; Wed, 5 Jan 2022 15:19:50 +0000 (UTC) Received: from localhost ([::1]:56476 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n584r-0002pg-P9 for qemu-devel@archiver.kernel.org; Wed, 05 Jan 2022 10:19:49 -0500 Received: from eggs.gnu.org ([209.51.188.92]:43288) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n583R-0000bx-AI for qemu-devel@nongnu.org; Wed, 05 Jan 2022 10:18:21 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:22724) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n583L-0007Jq-5F for qemu-devel@nongnu.org; Wed, 05 Jan 2022 10:18:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1641395894; 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=yvfv75l0XCF4ZHq2E/Kj1JEx0ejOmX6aX9UosCGgTLI=; b=FLSSwYtUAOUnH/41ieY5unUS9/jT2AZfpVbalgUDzYrKO0Sil/TvVX7i//HGONc4nLJL76 30SrvxaE02U9dqKF/I0HauPLDAupHGtsgzAMo5HXJ5BuwgbKUsjDSUfKpYbkv8XrlT0/6t kvVoHtMPqZHc1ls0SZ0ZindEIjpjoGg= 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-586-DTtQaoOyOQGOOU3L3TAETw-1; Wed, 05 Jan 2022 10:18:07 -0500 X-MC-Unique: DTtQaoOyOQGOOU3L3TAETw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EE4E7100E326; Wed, 5 Jan 2022 15:18:06 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.150]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CFBA87E8FB; Wed, 5 Jan 2022 15:18:04 +0000 (UTC) Date: Wed, 5 Jan 2022 15:18:02 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Laurent Vivier Subject: Re: [PATCH 1/1] softmmu: fix device deletion events with -device JSON syntax Message-ID: References: <20220105123847.4047954-1-berrange@redhat.com> <20220105123847.4047954-2-berrange@redhat.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.1.3 (2021-09-10) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 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: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.372, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, T_SPF_TEMPERROR=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: Kevin Wolf , Eduardo Habkost , Thomas Huth , Peter Krempa , qemu-devel@nongnu.org, Markus Armbruster , Paolo Bonzini , Eric Blake Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Jan 05, 2022 at 04:00:54PM +0100, Laurent Vivier wrote: > On 05/01/2022 15:55, Daniel P. Berrangé wrote: > > On Wed, Jan 05, 2022 at 03:49:12PM +0100, Laurent Vivier wrote: > > > On 05/01/2022 13:38, Daniel P. Berrangé wrote: > > > > The -device JSON syntax impl leaks a reference on the created > > > > DeviceState instance. As a result when you hot-unplug the > > > > device, the device_finalize method won't be called and thus > > > > it will fail to emit the required DEVICE_DELETED event. > > > > > > > > A 'json-cli' feature was previously added against the > > > > 'device_add' QMP command QAPI schema to indicated to mgmt > > > > apps that -device supported JSON syntax. Given the hotplug > > > > bug that feature flag is no unusable for its purpose, so > > > > > > Not sure to understand: do you mean "now unusable"? > > > > An application wants to known whether QEMU can support JSON > > syntax with -device. If they look for the 'json-cli' feature > > as a witness, they'll end up using JSON with QEMU 6.2 which > > is giving them broken hotplug. This is unusable for any > > non-trivial use cases. So we need a new witness to indicate > > whether JSON is viable with -device, that only the newly > > fixed QEMU will report. > > I understand that, my problem was with your sentence: > > "Given the hotplug bug that feature flag is no unusable for its purpose" What's the problem with that ? It is reasonabled to say a -device impl which is broken for hotplug is not usable for non-toy use cases. 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 :|