From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48899) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eC4go-00045B-6r for qemu-devel@nongnu.org; Tue, 07 Nov 2017 09:17:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eC4gk-00027W-Js for qemu-devel@nongnu.org; Tue, 07 Nov 2017 09:17:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41072) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eC4gk-000278-D8 for qemu-devel@nongnu.org; Tue, 07 Nov 2017 09:17:14 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3723F4AFC for ; Tue, 7 Nov 2017 14:17:13 +0000 (UTC) Date: Tue, 7 Nov 2017 15:17:05 +0100 From: Cornelia Huck Message-ID: <20171107151705.34ae33a7.cohuck@redhat.com> In-Reply-To: <1509617407-21191-3-git-send-email-thuth@redhat.com> References: <1509617407-21191-1-git-send-email-thuth@redhat.com> <1509617407-21191-3-git-send-email-thuth@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 2/2] qdev: Check for the availability of a hotplug controller before adding a device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth Cc: qemu-devel@nongnu.org, Eduardo Habkost , Igor Mammedov , "Dr. David Alan Gilbert" , Paolo Bonzini , Markus Armbruster , david@redhat.com On Thu, 2 Nov 2017 11:10:06 +0100 Thomas Huth wrote: > The qdev_unplug() function contains a g_assert(hotplug_ctrl) statement, > so QEMU crashes when the user tries to device_add + device_del a device > that does not have a corresponding hotplug controller. This could be > provoked for a couple of devices in the past (see commit 4c93950659487c7ad > or 84ebd3e8c7d4fe955 for example), and can currently for example also be > triggered like this: > > $ s390x-softmmu/qemu-system-s390x -M none -nographic > QEMU 2.10.50 monitor - type 'help' for more information > (qemu) device_add qemu-s390x-cpu,id=x > (qemu) device_del x > ** > ERROR:qemu/qdev-monitor.c:872:qdev_unplug: assertion failed: (hotplug_ctrl) > Aborted (core dumped) > > So devices clearly need a hotplug controller when they should be usable > with device_add. > The code in qdev_device_add() already checks whether the bus has a proper > hotplug controller, but for devices that do not have a corresponding bus, > there is no appropriate check available yet. In that case we should check > whether the machine itself provides a suitable hotplug controller and > refuse to plug the device if none is available. > > Reviewed-by: Igor Mammedov > Signed-off-by: Thomas Huth > --- > hw/core/qdev.c | 28 ++++++++++++++++++++-------- > include/hw/qdev-core.h | 1 + > qdev-monitor.c | 5 +++++ > 3 files changed, 26 insertions(+), 8 deletions(-) Reviewed-by: Cornelia Huck