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> --- v2: Add missing devices and dropped "RFC" status. See Eduardo's reply on the previous version of this patch for the rationale which devices need to be hotpluggable: https://lists.gnu.org/archive/html/qemu-devel/2017-09/msg06128.html hw/char/virtio-serial-bus.c | 1 + hw/core/qdev.c | 10 ++++------ hw/mem/nvdimm.c | 3 +++ hw/mem/pc-dimm.c | 1 + hw/pci/pci.c | 1 + hw/ppc/spapr_cpu_core.c | 1 + hw/s390x/ccw-device.c | 1 + hw/scsi/scsi-bus.c | 1 + hw/usb/bus.c | 1 + hw/usb/dev-smartcard-reader.c | 1 + hw/xen/xen_backend.c | 1 + target/i386/cpu.c | 4 ++-- target/s390x/cpu.c | 1 + 13 files changed, 19 insertions(+), 8 deletions(-) diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c index 17a1bb0..da26fc2 100644 --- a/hw/char/virtio-serial-bus.c +++ b/hw/char/virtio-serial-bus.c @@ -1097,6 +1097,7 @@ static void virtio_serial_port_class_init(ObjectClass *klass, void *data) k->realize = virtser_port_device_realize; k->unrealize = virtser_port_device_unrealize; k->props = virtser_props; + k->hotpluggable = true; } static const TypeInfo virtio_serial_port_type_info = { diff --git a/hw/core/qdev.c b/hw/core/qdev.c index d9ccce6..28fd92f 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -1125,13 +1125,11 @@ 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/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/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c index c08ee75..720284e 100644 --- a/hw/ppc/spapr_cpu_core.c +++ b/hw/ppc/spapr_cpu_core.c @@ -325,6 +325,7 @@ void spapr_cpu_core_class_init(ObjectClass *oc, void *data) dc->realize = spapr_cpu_core_realize; dc->unrealize = spapr_cpu_core_unrealizefn; dc->props = spapr_cpu_core_properties; + dc->hotpluggable = true; scc->cpu_class = cpu_class_by_name(TYPE_POWERPC_CPU, data); g_assert(scc->cpu_class); } 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 977f7bc..6703b2a 100644 --- a/hw/scsi/scsi-bus.c +++ b/hw/scsi/scsi-bus.c @@ -1741,6 +1741,7 @@ 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 = { diff --git a/hw/usb/dev-smartcard-reader.c b/hw/usb/dev-smartcard-reader.c index bef1f03..e28d1ba 100644 --- a/hw/usb/dev-smartcard-reader.c +++ b/hw/usb/dev-smartcard-reader.c @@ -1499,6 +1499,7 @@ static void ccid_card_class_init(ObjectClass *klass, void *data) k->init = ccid_card_init; k->exit = ccid_card_exit; k->props = ccid_props; + k->hotpluggable = true; } static const TypeInfo ccid_card_type_info = { diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c index c46cbb0..96621fe 100644 --- a/hw/xen/xen_backend.c +++ b/hw/xen/xen_backend.c @@ -620,6 +620,7 @@ static void xendev_class_init(ObjectClass *klass, void *data) set_bit(DEVICE_CATEGORY_MISC, dc->categories); /* xen-backend devices can be plugged/unplugged dynamically */ dc->user_creatable = true; + dc->hotpluggable = true; } static const TypeInfo xendev_type_info = { diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 0aa28fc..122623b 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -4170,6 +4170,8 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data) dc->realize = x86_cpu_realizefn; dc->unrealize = x86_cpu_unrealizefn; dc->props = x86_cpu_properties; + dc->user_creatable = true; + dc->hotpluggable = true; xcc->parent_reset = cc->reset; cc->reset = x86_cpu_reset; @@ -4215,8 +4217,6 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data) #endif cc->cpu_exec_enter = x86_cpu_exec_enter; cc->cpu_exec_exit = x86_cpu_exec_exit; - - dc->user_creatable = true; } static const TypeInfo x86_cpu_type_info = { diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c index 34538c3..ef61d19 100644 --- a/target/s390x/cpu.c +++ b/target/s390x/cpu.c @@ -462,6 +462,7 @@ static void s390_cpu_class_init(ObjectClass *oc, void *data) dc->realize = s390_cpu_realizefn; dc->props = s390x_cpu_properties; dc->user_creatable = true; + dc->hotpluggable = true; scc->parent_reset = cc->reset; #if !defined(CONFIG_USER_ONLY) -- 1.8.3.1
