Machine queue, 2019-03-06

* qdev: Hotplug handler chaining (David Hildenbrand)
 * qdev: fix qbus_is_full() (Tony Krowiak)
 * hostmem: fix crash when querying empty host-nodes property via
   QMP (Igor Mammedov)
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABCAAGBQJcgBPhAAoJECgHk2+YTcWmWF0P/jyKA7fmdgTTqmgIvJ4nR2On
 d57GZobD+w3XqPUKFXJaayiwRiGrvZqBE1wUF9lURIVqG1vQVD5AT2hLQfC3PMv5
 DbmDkWlVSdZ3fQLlvXI7kNXFdYt7ae2Xr/HDKJiPe8LXL8D0EW8puUT0ywu/ihz9
 dKGo7erjASKZb3481mUyNcsRjUHYXxzyb8PHWciAmzm/xIedwsCcyZOA/ulIYl3t
 sqC/KewaxcZkExuvEUUpI+sPMHxGbu4Xq6QbhDMbxxT0b1MFa6zuoivNLnEvRE1q
 ixsSkKP1n9WqpdWqz+dmG7W6YTmlEw2F7E2MIPsLKij8V7pOnryECmd9FF1l95Cc
 1Ul/c0WE1LY/dN0G/fKND1TjFuvXN27kFl+X3bi5Kno3FPPu6ajMWjaiAbW+QSbV
 ODyMGWvDjVj0lRCmIwxIWQIqKp2f9NOB8xbdY1qdPXgQJm2zryMyGAcUJTBWFcXB
 7udErPIszhm2qwsjPnSPFYdn8MZbvzUauoGVJqxH0sbQmN237h3/DyV/+vZ/ZiRx
 1a2G3oKckIS1AccEusFuVRIvx2wBTfsD/9beEw/io2eKxknbxyCyj6i/qcivqSUY
 POUc9+Iwk8dC0tw6VKnENXdzHSmo7ZuWnO0jcuu+k37AHHDGLu2PgcP3Hm+SyGIY
 QjeumpJafu5Ek1GJ6sKz
 =rUEC
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/ehabkost/tags/machine-next-pull-request' into staging

Machine queue, 2019-03-06

* qdev: Hotplug handler chaining (David Hildenbrand)
* qdev: fix qbus_is_full() (Tony Krowiak)
* hostmem: fix crash when querying empty host-nodes property via
  QMP (Igor Mammedov)

# gpg: Signature made Wed 06 Mar 2019 18:39:29 GMT
# gpg:                using RSA key 2807936F984DC5A6
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>" [full]
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/machine-next-pull-request:
  qdev: Provide qdev_get_bus_hotplug_handler()
  qdev: Let machine hotplug handler to override bus hotplug handler
  qdev: Let the hotplug_handler_unplug() caller delete the device
  hostmem: fix crash when querying empty host-nodes property via QMP
  qdev/core: fix qbus_is_full()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

backends/hostmem.c

@@ -88,7 +88,7 @@ host_memory_backend_get_host_nodes(Object *obj, Visitor *v, const char *name,
 
     value = find_first_bit(backend->host_nodes, MAX_NODES);
     if (value == MAX_NODES) {
-        return;
+        goto ret;
     }
 
     *node = g_malloc0(sizeof(**node));
@@ -106,6 +106,7 @@ host_memory_backend_get_host_nodes(Object *obj, Visitor *v, const char *name,
         node = &(*node)->next;
     } while (true);
 
+ret:
     visit_type_uint16List(v, name, &host_nodes, errp);
 }
 

hw/acpi/cpu.c

@@ -126,6 +126,7 @@ static void cpu_hotplug_wr(void *opaque, hwaddr addr, uint64_t data,
             dev = DEVICE(cdev->cpu);
             hotplug_ctrl = qdev_get_hotplug_handler(dev);
             hotplug_handler_unplug(hotplug_ctrl, dev, NULL);
+            object_unparent(OBJECT(dev));
         }
         break;
     case ACPI_CPU_CMD_OFFSET_WR:

hw/acpi/memory_hotplug.c

@@ -189,6 +189,7 @@ static void acpi_memory_hotplug_write(void *opaque, hwaddr addr, uint64_t data,
                 error_free(local_err);
                 break;
             }
+            object_unparent(OBJECT(dev));
             trace_mhp_acpi_pc_dimm_deleted(mem_st->selector);
         }
         break;

hw/acpi/pcihp.c

@@ -174,6 +174,7 @@ static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slo
             if (!acpi_pcihp_pc_no_hotplug(s, dev)) {
                 hotplug_ctrl = qdev_get_hotplug_handler(qdev);
                 hotplug_handler_unplug(hotplug_ctrl, qdev, &error_abort);
+                object_unparent(OBJECT(qdev));
             }
         }
     }
@@ -269,7 +270,7 @@ void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
 void acpi_pcihp_device_unplug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
                                  DeviceState *dev, Error **errp)
 {
-    object_unparent(OBJECT(dev));
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
 }
 
 void acpi_pcihp_device_unplug_request_cb(HotplugHandler *hotplug_dev,

hw/core/qdev.c

@@ -59,6 +59,8 @@ static void bus_remove_child(BusState *bus, DeviceState *child)
             snprintf(name, sizeof(name), "child[%d]", kid->index);
             QTAILQ_REMOVE(&bus->children, kid, sibling);
 
+            bus->num_children--;
+
             /* This gives back ownership of kid->child back to us.  */
             object_property_del(OBJECT(bus), name, NULL);
             object_unref(OBJECT(kid->child));
@@ -73,6 +75,7 @@ static void bus_add_child(BusState *bus, DeviceState *child)
     char name[32];
     BusChild *kid = g_malloc0(sizeof(*kid));
 
+    bus->num_children++;
     kid->index = bus->max_index++;
     kid->child = child;
     object_ref(OBJECT(kid->child));
@@ -233,14 +236,20 @@ HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev)
     return NULL;
 }
 
+HotplugHandler *qdev_get_bus_hotplug_handler(DeviceState *dev)
+{
+    if (dev->parent_bus) {
+        return dev->parent_bus->hotplug_handler;
+    }
+    return NULL;
+}
+
 HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev)
 {
-    HotplugHandler *hotplug_ctrl;
+    HotplugHandler *hotplug_ctrl = qdev_get_machine_hotplug_handler(dev);
 
-    if (dev->parent_bus && dev->parent_bus->hotplug_handler) {
+    if (hotplug_ctrl == NULL && dev->parent_bus) {
-        hotplug_ctrl = dev->parent_bus->hotplug_handler;
+        hotplug_ctrl = qdev_get_bus_hotplug_handler(dev);
-    } else {
-        hotplug_ctrl = qdev_get_machine_hotplug_handler(dev);
     }
     return hotplug_ctrl;
 }
@@ -286,8 +295,7 @@ void qbus_reset_all_fn(void *opaque)
 void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev,
                                   DeviceState *dev, Error **errp)
 {
-    /* just zap it */
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
-    object_unparent(OBJECT(dev));
 }
 
 /*

hw/i386/pc.c

@@ -2154,8 +2154,7 @@ static void pc_memory_unplug(HotplugHandler *hotplug_dev,
     }
 
     pc_dimm_unplug(PC_DIMM(dev), MACHINE(pcms));
-    object_unparent(OBJECT(dev));
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
-
  out:
     error_propagate(errp, local_err);
 }
@@ -2261,7 +2260,7 @@ static void pc_cpu_unplug_cb(HotplugHandler *hotplug_dev,
 
     found_cpu = pc_find_cpu_slot(MACHINE(pcms), cpu->apic_id, NULL);
     found_cpu->cpu = NULL;
-    object_unparent(OBJECT(dev));
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
 
     /* decrement the number of CPUs */
     pcms->boot_cpus--;

hw/pci/pci.c

@@ -428,7 +428,8 @@ PCIBus *pci_root_bus_new(DeviceState *parent, const char *name,
 void pci_root_bus_cleanup(PCIBus *bus)
 {
     pci_bus_uninit(bus);
-    object_unparent(OBJECT(bus));
+    /* the caller of the unplug hotplug handler will delete this device */
+    object_property_set_bool(OBJECT(bus), false, "realized", NULL);
 }
 
 void pci_bus_irqs(PCIBus *bus, pci_set_irq_fn set_irq, pci_map_irq_fn map_irq,

hw/pci/pcie.c

@@ -450,7 +450,7 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
 void pcie_cap_slot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
                              Error **errp)
 {
-    object_unparent(OBJECT(dev));
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
 }
 
 static void pcie_unplug_device(PCIBus *bus, PCIDevice *dev, void *opaque)
@@ -458,6 +458,7 @@ static void pcie_unplug_device(PCIBus *bus, PCIDevice *dev, void *opaque)
     HotplugHandler *hotplug_ctrl = qdev_get_hotplug_handler(DEVICE(dev));
 
     hotplug_handler_unplug(hotplug_ctrl, DEVICE(dev), &error_abort);
+    object_unparent(OBJECT(dev));
 }
 
 void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,

hw/pci/shpc.c

@@ -249,6 +249,7 @@ static void shpc_free_devices_in_slot(SHPCDevice *shpc, int slot)
             hotplug_ctrl = qdev_get_hotplug_handler(DEVICE(affected_dev));
             hotplug_handler_unplug(hotplug_ctrl, DEVICE(affected_dev),
                                    &error_abort);
+            object_unparent(OBJECT(affected_dev));
         }
     }
 }
@@ -546,7 +547,7 @@ void shpc_device_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
 void shpc_device_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
                            Error **errp)
 {
-    object_unparent(OBJECT(dev));
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
 }
 
 void shpc_device_unplug_request_cb(HotplugHandler *hotplug_dev,

hw/ppc/spapr.c

@@ -3595,6 +3595,7 @@ void spapr_lmb_release(DeviceState *dev)
      * unplug handler chain. This can never fail.
      */
     hotplug_handler_unplug(hotplug_ctrl, dev, &error_abort);
+    object_unparent(OBJECT(dev));
 }
 
 static void spapr_memory_unplug(HotplugHandler *hotplug_dev, DeviceState *dev)
@@ -3603,7 +3604,7 @@ static void spapr_memory_unplug(HotplugHandler *hotplug_dev, DeviceState *dev)
     sPAPRDIMMState *ds = spapr_pending_dimm_unplugs_find(spapr, PC_DIMM(dev));
 
     pc_dimm_unplug(PC_DIMM(dev), MACHINE(hotplug_dev));
-    object_unparent(OBJECT(dev));
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
     spapr_pending_dimm_unplugs_remove(spapr, ds);
 }
 
@@ -3667,6 +3668,7 @@ void spapr_core_release(DeviceState *dev)
 
     /* Call the unplug handler chain. This can never fail. */
     hotplug_handler_unplug(hotplug_ctrl, dev, &error_abort);
+    object_unparent(OBJECT(dev));
 }
 
 static void spapr_core_unplug(HotplugHandler *hotplug_dev, DeviceState *dev)
@@ -3689,7 +3691,7 @@ static void spapr_core_unplug(HotplugHandler *hotplug_dev, DeviceState *dev)
 
     assert(core_slot);
     core_slot->cpu = NULL;
-    object_unparent(OBJECT(dev));
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
 }
 
 static
@@ -3940,11 +3942,12 @@ void spapr_phb_release(DeviceState *dev)
     HotplugHandler *hotplug_ctrl = qdev_get_hotplug_handler(dev);
 
     hotplug_handler_unplug(hotplug_ctrl, dev, &error_abort);
+    object_unparent(OBJECT(dev));
 }
 
 static void spapr_phb_unplug(HotplugHandler *hotplug_dev, DeviceState *dev)
 {
-    object_unparent(OBJECT(dev));
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
 }
 
 static void spapr_phb_unplug_request(HotplugHandler *hotplug_dev,

hw/ppc/spapr_pci.c

@@ -1379,6 +1379,7 @@ void spapr_phb_remove_pci_device_cb(DeviceState *dev)
     HotplugHandler *hotplug_ctrl = qdev_get_hotplug_handler(dev);
 
     hotplug_handler_unplug(hotplug_ctrl, dev, &error_abort);
+    object_unparent(OBJECT(dev));
 }
 
 static sPAPRDRConnector *spapr_phb_get_pci_func_drc(sPAPRPHBState *phb,
@@ -1506,7 +1507,7 @@ static void spapr_pci_unplug(HotplugHandler *plug_handler,
      * an 'idle' state, as the device cleanup code expects.
      */
     pci_device_reset(PCI_DEVICE(plugged_dev));
-    object_unparent(OBJECT(plugged_dev));
+    object_property_set_bool(OBJECT(plugged_dev), false, "realized", NULL);
 }
 
 static void spapr_pci_unplug_request(HotplugHandler *plug_handler,

hw/s390x/css-bridge.c

@@ -51,7 +51,7 @@ static void ccw_device_unplug(HotplugHandler *hotplug_dev,
 
     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid, 1, 0);
 
-    object_unparent(OBJECT(dev));
+    object_property_set_bool(OBJECT(dev), false, "realized", NULL);
 }
 
 static void virtual_css_bus_reset(BusState *qbus)

hw/s390x/s390-pci-bus.c

@@ -154,14 +154,17 @@ static void s390_pci_perform_unplug(S390PCIBusDevice *pbdev)
 
     /* Unplug the PCI device */
     if (pbdev->pdev) {
-        hotplug_ctrl = qdev_get_hotplug_handler(DEVICE(pbdev->pdev));
+        DeviceState *pdev = DEVICE(pbdev->pdev);
-        hotplug_handler_unplug(hotplug_ctrl, DEVICE(pbdev->pdev),
+
-                               &error_abort);
+        hotplug_ctrl = qdev_get_hotplug_handler(pdev);
+        hotplug_handler_unplug(hotplug_ctrl, pdev, &error_abort);
+        object_unparent(OBJECT(pdev));
     }
 
     /* Unplug the zPCI device */
     hotplug_ctrl = qdev_get_hotplug_handler(DEVICE(pbdev));
     hotplug_handler_unplug(hotplug_ctrl, DEVICE(pbdev), &error_abort);
+    object_unparent(OBJECT(pbdev));
 }
 
 void s390_pci_sclp_deconfigure(SCCB *sccb)
@@ -994,7 +997,7 @@ static void s390_pcihost_unplug(HotplugHandler *hotplug_dev, DeviceState *dev,
                                      pbdev->fh, pbdev->fid);
         bus = pci_get_bus(pci_dev);
         devfn = pci_dev->devfn;
-        object_unparent(OBJECT(pci_dev));
+        object_property_set_bool(OBJECT(dev), false, "realized", NULL);
 
         s390_pci_msix_free(pbdev);
         s390_pci_iommu_free(s, bus, devfn);
@@ -1005,7 +1008,7 @@ static void s390_pcihost_unplug(HotplugHandler *hotplug_dev, DeviceState *dev,
         pbdev->fid = 0;
         QTAILQ_REMOVE(&s->zpci_devs, pbdev, link);
         g_hash_table_remove(s->zpci_table, &pbdev->idx);
-        object_unparent(OBJECT(pbdev));
+        object_property_set_bool(OBJECT(dev), false, "realized", NULL);
     }
 }
 

include/hw/qdev-core.h

@@ -206,6 +206,7 @@ struct BusState {
     HotplugHandler *hotplug_handler;
     int max_index;
     bool realized;
+    int num_children;
     QTAILQ_HEAD(, BusChild) children;
     QLIST_ENTRY(BusState) sibling;
 };
@@ -280,7 +281,19 @@ 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_bus_hotplug_handler(DeviceState *dev);
 HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev);
+/**
+ * qdev_get_hotplug_handler: Get handler responsible for device wiring
+ *
+ * Find HOTPLUG_HANDLER for @dev that provides [pre|un]plug callbacks for it.
+ *
+ * Note: in case @dev has a parent bus, it will be returned as handler unless
+ * machine handler overrides it.
+ *
+ * Returns: pointer to object that implements TYPE_HOTPLUG_HANDLER interface
+ *          or NULL if there aren't any.
+ */
 HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev);
 void qdev_unplug(DeviceState *dev, Error **errp);
 void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev,

qdev-monitor.c

@@ -414,7 +414,7 @@ static DeviceState *qbus_find_dev(BusState *bus, char *elem)
 static inline bool qbus_is_full(BusState *bus)
 {
     BusClass *bus_class = BUS_GET_CLASS(bus);
-    return bus_class->max_dev && bus->max_index >= bus_class->max_dev;
+    return bus_class->max_dev && bus->num_children >= bus_class->max_dev;
 }
 
 /*
@@ -862,6 +862,7 @@ void qdev_unplug(DeviceState *dev, Error **errp)
     DeviceClass *dc = DEVICE_GET_CLASS(dev);
     HotplugHandler *hotplug_ctrl;
     HotplugHandlerClass *hdc;
+    Error *local_err = NULL;
 
     if (dev->parent_bus && !qbus_is_hotpluggable(dev->parent_bus)) {
         error_setg(errp, QERR_BUS_NO_HOTPLUG, dev->parent_bus->name);
@@ -890,10 +891,14 @@ void qdev_unplug(DeviceState *dev, Error **errp)
      * otherwise just remove it synchronously */
     hdc = HOTPLUG_HANDLER_GET_CLASS(hotplug_ctrl);
     if (hdc->unplug_request) {
-        hotplug_handler_unplug_request(hotplug_ctrl, dev, errp);
+        hotplug_handler_unplug_request(hotplug_ctrl, dev, &local_err);
     } else {
-        hotplug_handler_unplug(hotplug_ctrl, dev, errp);
+        hotplug_handler_unplug(hotplug_ctrl, dev, &local_err);
+        if (!local_err) {
+            object_unparent(OBJECT(dev));
+        }
     }
+    error_propagate(errp, local_err);
 }
 
 void qmp_device_del(const char *id, Error **errp)