Historically we've marked all devices as hotpluggable by default. However, most devices are not hotpluggable, and you also need a HotplugHandler to support these devices. So if the user tries to "device_add" or "device_del" such a non-hotpluggable device during runtime, either nothing really usable happens, or QEMU even crashes/aborts unexpectedly (see for example commit 84ebd3e8c7d4fe955b - "Mark diag288 watchdog as non-hotpluggable"). So let's change this dangerous default behaviour and mark the devices as non-hotpluggable by default. Certain parent devices classes which are known as hotpluggable (e.g. PCI, USB, etc.) are marked with "hotpluggable = true", so that devices that are derived from these classes continue to work as expected.
Signed-off-by: Thomas Huth <th...@redhat.com> --- Note: I've marked the patch as RFC since I'm not 100% sure whether I've correctly identified all devices that should still be marked as hot- pluggable. Feedback is welcome! hw/core/qdev.c | 10 ++++------ hw/cpu/core.c | 1 + hw/mem/nvdimm.c | 3 +++ hw/mem/pc-dimm.c | 1 + hw/pci/pci.c | 1 + hw/s390x/ccw-device.c | 1 + hw/scsi/scsi-bus.c | 1 + hw/usb/bus.c | 1 + 8 files changed, 13 insertions(+), 6 deletions(-) diff --git a/hw/core/qdev.c b/hw/core/qdev.c index 606ab53..c4f1902 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -1120,13 +1120,11 @@ static void device_class_init(ObjectClass *class, void *data) dc->realize = device_realize; dc->unrealize = device_unrealize; - /* by default all devices were considered as hotpluggable, - * so with intent to check it in generic qdev_unplug() / - * device_set_realized() functions make every device - * hotpluggable. Devices that shouldn't be hotpluggable, - * should override it in their class_init() + /* + * All devices are considered as cold-pluggable by default. The devices + * that are hotpluggable should override it in their class_init(). */ - dc->hotpluggable = true; + dc->hotpluggable = false; dc->user_creatable = true; } diff --git a/hw/cpu/core.c b/hw/cpu/core.c index bd578ab..01660aa 100644 --- a/hw/cpu/core.c +++ b/hw/cpu/core.c @@ -82,6 +82,7 @@ static void cpu_core_class_init(ObjectClass *oc, void *data) DeviceClass *dc = DEVICE_CLASS(oc); set_bit(DEVICE_CATEGORY_CPU, dc->categories); + dc->hotpluggable = true; } static const TypeInfo cpu_core_type_info = { diff --git a/hw/mem/nvdimm.c b/hw/mem/nvdimm.c index 952fce5..02be9f3 100644 --- a/hw/mem/nvdimm.c +++ b/hw/mem/nvdimm.c @@ -148,9 +148,12 @@ static MemoryRegion *nvdimm_get_vmstate_memory_region(PCDIMMDevice *dimm) static void nvdimm_class_init(ObjectClass *oc, void *data) { + DeviceClass *dc = DEVICE_CLASS(oc); PCDIMMDeviceClass *ddc = PC_DIMM_CLASS(oc); NVDIMMClass *nvc = NVDIMM_CLASS(oc); + dc->hotpluggable = true; + ddc->realize = nvdimm_realize; ddc->get_memory_region = nvdimm_get_memory_region; ddc->get_vmstate_memory_region = nvdimm_get_vmstate_memory_region; diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c index 66eace5..1f78567 100644 --- a/hw/mem/pc-dimm.c +++ b/hw/mem/pc-dimm.c @@ -443,6 +443,7 @@ static void pc_dimm_class_init(ObjectClass *oc, void *data) dc->unrealize = pc_dimm_unrealize; dc->props = pc_dimm_properties; dc->desc = "DIMM memory module"; + dc->hotpluggable = true; ddc->get_memory_region = pc_dimm_get_memory_region; ddc->get_vmstate_memory_region = pc_dimm_get_vmstate_memory_region; diff --git a/hw/pci/pci.c b/hw/pci/pci.c index 1e6fb88..8db380d 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -2534,6 +2534,7 @@ static void pci_device_class_init(ObjectClass *klass, void *data) k->unrealize = pci_qdev_unrealize; k->bus_type = TYPE_PCI_BUS; k->props = pci_props; + k->hotpluggable = true; pc->realize = pci_default_realize; } diff --git a/hw/s390x/ccw-device.c b/hw/s390x/ccw-device.c index f9bfa15..d1b6e6f 100644 --- a/hw/s390x/ccw-device.c +++ b/hw/s390x/ccw-device.c @@ -48,6 +48,7 @@ static void ccw_device_class_init(ObjectClass *klass, void *data) k->realize = ccw_device_realize; k->refill_ids = ccw_device_refill_ids; dc->props = ccw_device_properties; + dc->hotpluggable = true; } const VMStateDescription vmstate_ccw_dev = { diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c index e364410..338180d 100644 --- a/hw/scsi/scsi-bus.c +++ b/hw/scsi/scsi-bus.c @@ -2123,6 +2123,7 @@ static void scsi_device_class_init(ObjectClass *klass, void *data) k->realize = scsi_qdev_realize; k->unrealize = scsi_qdev_unrealize; k->props = scsi_props; + k->hotpluggable = true; } static void scsi_dev_instance_init(Object *obj) diff --git a/hw/usb/bus.c b/hw/usb/bus.c index d910f84..16701aa 100644 --- a/hw/usb/bus.c +++ b/hw/usb/bus.c @@ -793,6 +793,7 @@ static void usb_device_class_init(ObjectClass *klass, void *data) k->realize = usb_qdev_realize; k->unrealize = usb_qdev_unrealize; k->props = usb_props; + k->hotpluggable = true; } static const TypeInfo usb_device_type_info = { -- 1.8.3.1