On Tue, Sep 19, 2017 at 10:55:53AM +0200, Thomas Huth wrote: > 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.
These seem to be missing: * TYPE_CPU (or at least TYPE_X86_CPU and TYPE_S390_CPU) * TYPE_VIRTIO_SERIAL_PORT * TYPE_CCID_CARD * TYPE_XENSYSDEV Also, I don't think we need to set it for TYPE_CPU_CORE, just for TYPE_SPAPR_CPU_CORE. For reference, the full list of qbus_set*hotplug_handler() callers is: hw/acpi/piix4.c=439=static void piix4_update_bus_hotplug(PCIBus *pci_bus, void *opaque) hw/acpi/piix4.c:445: qbus_set_hotplug_handler(BUS(pci_bus), DEVICE(s), &error_abort); hw/char/virtio-serial-bus.c=1015=static void virtio_serial_device_realize(DeviceState *dev, Error **errp) hw/char/virtio-serial-bus.c:1045: qbus_set_hotplug_handler(BUS(&vser->bus), DEVICE(vser), errp); hw/char/virtio-serial-bus.c=1111=static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp) hw/char/virtio-serial-bus.c:1128: qbus_set_hotplug_handler(BUS(&vser->bus), NULL, errp); hw/pci/pcie.c=392=void pcie_cap_slot_init(PCIDevice *dev, uint16_t slot) hw/pci/pcie.c:445: qbus_set_hotplug_handler(BUS(pci_bridge_get_sec_bus(PCI_BRIDGE(dev))), hw/pci/shpc.c=585=int shpc_init(PCIDevice *d, PCIBus *sec_bus, MemoryRegion *bar, hw/pci/shpc.c:651: qbus_set_hotplug_handler(BUS(sec_bus), DEVICE(d), NULL); hw/ppc/spapr_pci.c=1508=static void spapr_phb_realize(DeviceState *dev, Error **errp) hw/ppc/spapr_pci.c:1657: qbus_set_hotplug_handler(BUS(phb->bus), DEVICE(sphb), NULL); hw/s390x/css-bridge.c=94=VirtualCssBus *virtual_css_bus_init(void) hw/s390x/css-bridge.c:110: qbus_set_hotplug_handler(bus, dev, &error_abort); hw/s390x/s390-pci-bus.c=548=static int s390_pcihost_init(SysBusDevice *dev) hw/s390x/s390-pci-bus.c:564: qbus_set_hotplug_handler(bus, DEVICE(dev), NULL); hw/s390x/s390-pci-bus.c:568: qbus_set_hotplug_handler(BUS(s->bus), DEVICE(s), NULL); hw/s390x/s390-pci-bus.c=660=static void s390_pcihost_hot_plug(HotplugHandler *hotplug_dev, hw/s390x/s390-pci-bus.c:676: qbus_set_hotplug_handler(bus, DEVICE(s), errp); hw/scsi/scsi-bus.c=91=void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host, hw/scsi/scsi-bus.c:97: qbus_set_bus_hotplug_handler(BUS(bus), &error_abort); hw/scsi/virtio-scsi.c=877=static void virtio_scsi_device_realize(DeviceState *dev, Error **errp) hw/scsi/virtio-scsi.c:896: qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort); hw/scsi/virtio-scsi.c=910=static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp) hw/scsi/virtio-scsi.c:914: qbus_set_hotplug_handler(BUS(&s->bus), NULL, &error_abort); hw/scsi/vmw_pvscsi.c=1107=pvscsi_realizefn(PCIDevice *pci_dev, Error **errp) hw/scsi/vmw_pvscsi.c:1145: qbus_set_hotplug_handler(BUS(&s->bus), DEVICE(s), &error_abort); hw/usb/bus.c=88=void usb_bus_new(USBBus *bus, size_t bus_size, hw/usb/bus.c:92: qbus_set_bus_hotplug_handler(BUS(bus), &error_abort); hw/usb/dev-smartcard-reader.c=1332=static void ccid_realize(USBDevice *dev, Error **errp) hw/usb/dev-smartcard-reader.c:1340: qbus_set_hotplug_handler(BUS(&s->bus), DEVICE(dev), &error_abort); hw/xen/xen_backend.c=520=int xen_be_init(void) hw/xen/xen_backend.c:538: qbus_set_bus_hotplug_handler(xen_sysbus, &error_abort); The full list of machine-provided hotplug handler callbacks is: hw/i386/pc.c:2302: pcmc->get_hotplug_handler = mc->get_hotplug_handler; hw/i386/pc.c:2317: mc->get_hotplug_handler = pc_get_hotpug_handler; hw/ppc/spapr.c:3582: mc->get_hotplug_handler = spapr_get_hotplug_handler; hw/s390x/s390-virtio-ccw.c:446: mc->get_hotplug_handler = s390_get_hotplug_handler; Details for each item: hw/i386/pc.c:2302: pcmc->get_hotplug_handler = mc->get_hotplug_handler; hw/i386/pc.c:2317: mc->get_hotplug_handler = pc_get_hotpug_handler; pc_get_hotpug_handler accepts: * TYPE_PC_DIMM * TYPE_CPU hw/ppc/spapr.c:3582: mc->get_hotplug_handler = spapr_get_hotplug_handler; spapr_get_hotplug_handler accepts: * TYPE_PC_DIMM * TYPE_SPAPR_CPU_CORE hw/s390x/s390-virtio-ccw.c:446: mc->get_hotplug_handler = s390_get_hotplug_handler; s390_get_hotplug_handler accepts: * TYPE_CPU hw/acpi/piix4.c=439=static void piix4_update_bus_hotplug(PCIBus *pci_bus, void *opaque) hw/acpi/piix4.c:445: qbus_set_hotplug_handler(BUS(pci_bus), DEVICE(s), &error_abort); * It looks like this is set only for PCI buses, but piix4_device_plug_cb() handles: TYPE_PC_DIMM, TYPE_NVDIMM, TYPE_PCI_DEVICE, and TYPE_CPU. It isn't clear how piix4_device_plug_cb() ends up getting called for non-PCI devices. But this patch handle all of them except TYPE_CPU, anyway. hw/char/virtio-serial-bus.c=1015=static void virtio_serial_device_realize(DeviceState *dev, Error **errp) hw/char/virtio-serial-bus.c:1045: qbus_set_hotplug_handler(BUS(&vser->bus), DEVICE(vser), errp); hw/char/virtio-serial-bus.c=1111=static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp) hw/char/virtio-serial-bus.c:1128: qbus_set_hotplug_handler(BUS(&vser->bus), NULL, errp); * vser->bus is VirtIOSerialBus, which accepts hotplug of TYPE_VIRTIO_SERIAL_PORT devices. Missing from this patch. hw/pci/pcie.c=392=void pcie_cap_slot_init(PCIDevice *dev, uint16_t slot) hw/pci/pcie.c:445: qbus_set_hotplug_handler(BUS(pci_bridge_get_sec_bus(PCI_BRIDGE(dev))), hw/pci/shpc.c=585=int shpc_init(PCIDevice *d, PCIBus *sec_bus, MemoryRegion *bar, hw/pci/shpc.c:651: qbus_set_hotplug_handler(BUS(sec_bus), DEVICE(d), NULL); hw/ppc/spapr_pci.c=1508=static void spapr_phb_realize(DeviceState *dev, Error **errp) hw/ppc/spapr_pci.c:1657: qbus_set_hotplug_handler(BUS(phb->bus), DEVICE(sphb), NULL); * These are a bit confusing because the actual TYPE_HOTPLUG_HANDLER method implementations are not at the same files as the qbus_set_hotplug_handler() calls, but it seems to work, and they only affect TYPE_PCI anyway. hw/s390x/css-bridge.c=94=VirtualCssBus *virtual_css_bus_init(void) hw/s390x/css-bridge.c:110: qbus_set_hotplug_handler(bus, dev, &error_abort); * This seems to be for TYPE_CCW_DEVICE hw/s390x/s390-pci-bus.c=548=static int s390_pcihost_init(SysBusDevice *dev) hw/s390x/s390-pci-bus.c:564: qbus_set_hotplug_handler(bus, DEVICE(dev), NULL); hw/s390x/s390-pci-bus.c:568: qbus_set_hotplug_handler(BUS(s->bus), DEVICE(s), NULL); hw/s390x/s390-pci-bus.c=660=static void s390_pcihost_hot_plug(HotplugHandler *hotplug_dev, hw/s390x/s390-pci-bus.c:676: qbus_set_hotplug_handler(bus, DEVICE(s), errp); * TYPE_PCI only, it seems. hw/scsi/scsi-bus.c=91=void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host, hw/scsi/scsi-bus.c:97: qbus_set_bus_hotplug_handler(BUS(bus), &error_abort); * For TYPE_SCSI_DEVICE hw/scsi/virtio-scsi.c=877=static void virtio_scsi_device_realize(DeviceState *dev, Error **errp) hw/scsi/virtio-scsi.c:896: qbus_set_hotplug_handler(BUS(&s->bus), dev, &error_abort); hw/scsi/virtio-scsi.c=910=static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp) hw/scsi/virtio-scsi.c:914: qbus_set_hotplug_handler(BUS(&s->bus), NULL, &error_abort); * s->bus is a SCSIBus. TYPE_SCSI_DEVICE only, it seems. hw/scsi/vmw_pvscsi.c=1107=pvscsi_realizefn(PCIDevice *pci_dev, Error **errp) hw/scsi/vmw_pvscsi.c:1145: qbus_set_hotplug_handler(BUS(&s->bus), DEVICE(s), &error_abort); * s->bus is a SCSIBus. TYPE_SCSI_DEVICE only, it seems. hw/usb/bus.c=88=void usb_bus_new(USBBus *bus, size_t bus_size, hw/usb/bus.c:92: qbus_set_bus_hotplug_handler(BUS(bus), &error_abort); * For TYPE_USB_DEVICE hw/usb/dev-smartcard-reader.c=1332=static void ccid_realize(USBDevice *dev, Error **errp) hw/usb/dev-smartcard-reader.c:1340: qbus_set_hotplug_handler(BUS(&s->bus), DEVICE(dev), &error_abort); * s->bus is a CCIDBus. This is for TYPE_CCID_CARD. Missing from this patch. hw/xen/xen_backend.c=520=int xen_be_init(void) hw/xen/xen_backend.c:538: qbus_set_bus_hotplug_handler(xen_sysbus, &error_abort); * xen_sysbus is a TYPE_XENSYSBUS, which accepts hotplug of TYPE_XENSYSDEV devices. Missing from this patch. > > 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 > > -- Eduardo