Message ID | 1507206738-816-3-git-send-email-thuth@redhat.com |
---|---|
State | New |
Headers | show |
Series | Check for the availability of a hotplug controller before adding a device | expand |
On Thu, 5 Oct 2017 14:32:18 +0200 Thomas Huth <thuth@redhat.com> 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). 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. > > Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> > --- > v2: > - Do the check earlier in qdev_device_add > - Use common new err_dev_del handler in case of failure > > hw/core/qdev.c | 28 ++++++++++++++++++++-------- > include/hw/qdev-core.h | 1 + > qdev-monitor.c | 5 +++++ > 3 files changed, 26 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 cb2b109..f93455f 100644 > --- a/qdev-monitor.c > +++ b/qdev-monitor.c > @@ -614,6 +614,11 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) > > if (bus) { > qdev_set_parent_bus(dev, bus); > + } else if (qdev_hotplug && !qdev_get_machine_hotplug_handler(dev)) { > + /* No bus, no machine hotplug handler --> device is not hotpluggable */ > + error_setg(&err, "Device '%s' can not be hotplugged on this machine", > + driver); > + goto err_del_dev; > } > > qdev_set_id(dev, qemu_opts_id(opts));
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 cb2b109..f93455f 100644 --- a/qdev-monitor.c +++ b/qdev-monitor.c @@ -614,6 +614,11 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) if (bus) { qdev_set_parent_bus(dev, bus); + } else if (qdev_hotplug && !qdev_get_machine_hotplug_handler(dev)) { + /* No bus, no machine hotplug handler --> device is not hotpluggable */ + error_setg(&err, "Device '%s' can not be hotplugged on this machine", + driver); + goto err_del_dev; } qdev_set_id(dev, qemu_opts_id(opts));
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 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. Signed-off-by: Thomas Huth <thuth@redhat.com> --- v2: - Do the check earlier in qdev_device_add - Use common new err_dev_del handler in case of failure hw/core/qdev.c | 28 ++++++++++++++++++++-------- include/hw/qdev-core.h | 1 + qdev-monitor.c | 5 +++++ 3 files changed, 26 insertions(+), 8 deletions(-)