On Thu, 2 Nov 2017 11:10:06 +0100 Thomas Huth <th...@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), 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 <imamm...@redhat.com> > Signed-off-by: Thomas Huth <th...@redhat.com> > --- > 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 <coh...@redhat.com>