[v15,09/15] add check reset mechanism when hotplug vfio device

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 168b9cc..f6ca6ef 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -81,6 +81,7 @@  static void pci_bus_realize(BusState *qbus, Error **errp)
     PCIBus *bus = PCI_BUS(qbus);
 
     vmstate_register(NULL, -1, &vmstate_pcibus, bus);
+    notifier_with_return_list_init(&bus->hotplug_notifiers);
 }
 
 static void pci_bus_unrealize(BusState *qbus, Error **errp)
@@ -1835,6 +1836,22 @@  PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn)
     return bus->devices[devfn];
 }
 
+void pci_bus_add_hotplug_notifier(PCIBus *bus, NotifierWithReturn *notify)
+{
+    notifier_with_return_list_add(&bus->hotplug_notifiers, notify);
+}
+
+void pci_bus_remove_hotplug_notifier(NotifierWithReturn *notifier)
+{
+    notifier_with_return_remove(notifier);
+}
+
+static int pci_bus_hotplug_notifier(PCIBus *bus, void *opaque)
+{
+    return notifier_with_return_list_notify(&bus->hotplug_notifiers,
+                                            opaque);
+}
+
 static void pci_qdev_realize(DeviceState *qdev, Error **errp)
 {
     PCIDevice *pci_dev = (PCIDevice *)qdev;
@@ -1877,6 +1894,18 @@  static void pci_qdev_realize(DeviceState *qdev, Error **errp)
         pci_qdev_unrealize(DEVICE(pci_dev), NULL);
         return;
     }
+
+    /*
+     *  If the function is func 0, indicate the closure of the slot.
+     *  signal the callback.
+     */
+    if (DEVICE(pci_dev)->hotplugged &&
+        pci_get_function_0(pci_dev) == pci_dev &&
+        pci_bus_hotplug_notifier(bus, pci_dev)) {
+        error_setg(errp, "failed to hotplug function 0");
+        pci_qdev_unrealize(DEVICE(pci_dev), NULL);
+        return;
+    }
 }
 
 static void pci_default_realize(PCIDevice *dev, Error **errp)
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 16ab0e3..ff25c9b 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2044,6 +2044,19 @@  static int vfio_check_devices_host_bus_reset(void)
     return 0;
 }
 
+static int vfio_check_bus_reset(NotifierWithReturn *n, void *opaque)
+{
+    VFIOPCIDevice *vdev = container_of(n, VFIOPCIDevice, hotplug_notifier);
+    PCIDevice *pci_dev = PCI_DEVICE(vdev);
+    PCIDevice *pci_func0 = opaque;
+
+    if (pci_get_function_0(pci_dev) != pci_func0) {
+        return 0;
+    }
+
+    return vfio_check_host_bus_reset(vdev);
+}
+
 static int vfio_setup_aer(VFIOPCIDevice *vdev, uint8_t cap_ver,
                           int pos, uint16_t size)
 {
@@ -2091,6 +2104,9 @@  static int vfio_setup_aer(VFIOPCIDevice *vdev, uint8_t cap_ver,
         pdev->exp.aer_log.log_max = 0;
     }
 
+    vdev->hotplug_notifier.notify = vfio_check_bus_reset;
+    pci_bus_add_hotplug_notifier(pdev->bus, &vdev->hotplug_notifier);
+
     pcie_cap_deverr_init(pdev);
     return pcie_aer_init(pdev, pos, size);
 
@@ -2972,6 +2988,9 @@  static void vfio_exitfn(PCIDevice *pdev)
     vfio_unregister_req_notifier(vdev);
     vfio_unregister_err_notifier(vdev);
     pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
+    if (vdev->features & VFIO_FEATURE_ENABLE_AER) {
+        pci_bus_remove_hotplug_notifier(&vdev->hotplug_notifier);
+    }
     vfio_disable_interrupts(vdev);
     if (vdev->intx.mmap_timer) {
         timer_free(vdev->intx.mmap_timer);
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 59ae194..b385f07 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -142,6 +142,8 @@  typedef struct VFIOPCIDevice {
     bool no_kvm_intx;
     bool no_kvm_msi;
     bool no_kvm_msix;
+
+    NotifierWithReturn hotplug_notifier;
 } VFIOPCIDevice;
 
 uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len);
diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h
index 403fec6..7812fa9 100644
--- a/include/hw/pci/pci_bus.h
+++ b/include/hw/pci/pci_bus.h
@@ -39,8 +39,13 @@  struct PCIBus {
        Keep a count of the number of devices with raised IRQs.  */
     int nirq;
     int *irq_count;
+
+    NotifierWithReturnList hotplug_notifiers;
 };
 
+void pci_bus_add_hotplug_notifier(PCIBus *bus, NotifierWithReturn *notify);
+void pci_bus_remove_hotplug_notifier(NotifierWithReturn *notify);
+
 typedef struct PCIBridgeWindows PCIBridgeWindows;
 
 /*