From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45180) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dzQKk-0001JZ-AJ for qemu-devel@nongnu.org; Tue, 03 Oct 2017 12:46:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dzQKf-0001lZ-DE for qemu-devel@nongnu.org; Tue, 03 Oct 2017 12:46:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51658) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dzQKf-0001lA-2K for qemu-devel@nongnu.org; Tue, 03 Oct 2017 12:46:09 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 0E3815F298D for ; Tue, 3 Oct 2017 16:46:08 +0000 (UTC) From: Thomas Huth Date: Tue, 3 Oct 2017 18:46:02 +0200 Message-Id: <1507049162-27026-1-git-send-email-thuth@redhat.com> Subject: [Qemu-devel] [PATCH] 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: qemu-devel@nongnu.org, Eduardo Habkost Cc: Markus Armbruster , "Dr. David Alan Gilbert" , Igor Mammedov , Paolo Bonzini 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). So devices clearly need a hotplug controller when they are suitable for 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. 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. Signed-off-by: Thomas Huth --- This is the follow-up patch from my earlier try "hw/core/qdev: Do not allow hot-plugging without hotplug controller" ... AFAICS the function qdev_device_add() is now the right spot to do the check. hw/core/qdev.c | 28 ++++++++++++++++++++-------- include/hw/qdev-core.h | 1 + qdev-monitor.c | 9 +++++++++ 3 files changed, 30 insertions(+), 8 deletions(-) diff --git a/hw/core/qdev.c b/hw/core/qdev.c index 606ab53..a953ec9 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -253,19 +253,31 @@ void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id, dev->alias_required_for_version = required_for_version; } +HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev) +{ + MachineState *machine; + MachineClass *mc; + Object *m_obj = qdev_get_machine(); + + if (object_dynamic_cast(m_obj, TYPE_MACHINE)) { + machine = MACHINE(m_obj); + mc = MACHINE_GET_CLASS(machine); + if (mc->get_hotplug_handler) { + return mc->get_hotplug_handler(machine, dev); + } + } + + return NULL; +} + HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev) { - HotplugHandler *hotplug_ctrl = NULL; + HotplugHandler *hotplug_ctrl; if (dev->parent_bus && dev->parent_bus->hotplug_handler) { hotplug_ctrl = dev->parent_bus->hotplug_handler; - } else if (object_dynamic_cast(qdev_get_machine(), TYPE_MACHINE)) { - MachineState *machine = MACHINE(qdev_get_machine()); - MachineClass *mc = MACHINE_GET_CLASS(machine); - - if (mc->get_hotplug_handler) { - hotplug_ctrl = mc->get_hotplug_handler(machine, dev); - } + } else { + hotplug_ctrl = qdev_get_machine_hotplug_handler(dev); } return hotplug_ctrl; } diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index 0891461..5aa536d 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -285,6 +285,7 @@ DeviceState *qdev_try_create(BusState *bus, const char *name); void qdev_init_nofail(DeviceState *dev); void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id, int required_for_version); +HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev); HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev); void qdev_unplug(DeviceState *dev, Error **errp); void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev, diff --git a/qdev-monitor.c b/qdev-monitor.c index 8fd6df9..2891dde 100644 --- a/qdev-monitor.c +++ b/qdev-monitor.c @@ -626,6 +626,15 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) return NULL; } + /* In case we don't have a bus, there must be a machine hotplug handler */ + if (qdev_hotplug && !bus && !qdev_get_machine_hotplug_handler(dev)) { + error_setg(errp, "Device '%s' can not be hotplugged on this machine", + driver); + object_unparent(OBJECT(dev)); + object_unref(OBJECT(dev)); + return NULL; + } + dev->opts = opts; object_property_set_bool(OBJECT(dev), true, "realized", &err); if (err != NULL) { -- 1.8.3.1