[Qemu-devel] [PATCH 3/5] hotplug: introduce qdev_unplug_ack() to remove device from views

[Liu Ping Fan <qemulist@gmail.com>]

From: Liu Ping Fan <pingfank@linux.vnet.ibm.com>

When guest confirm the removal of device, we should
--unmap from MemoryRegion view
--isolated from device tree view

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 hw/acpi_piix4.c |    4 ++--
 hw/qdev.c       |   28 ++++++++++++++++++++++++++++
 hw/qdev.h       |    3 ++-
 3 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
index 0aace60..c174247 100644
--- a/hw/acpi_piix4.c
+++ b/hw/acpi_piix4.c
@@ -305,8 +305,8 @@ static void acpi_piix_eject_slot(PIIX4PMState *s, unsigned slots)
             if (pc->no_hotplug) {
                 slot_free = false;
             } else {
-                object_unparent(OBJECT(dev));
-                qdev_free(qdev);
+                /* refcnt will be decreased */
+                qdev_unplug_ack(qdev, NULL);
             }
         }
     }
diff --git a/hw/qdev.c b/hw/qdev.c
index ac55e45..3f7dfa5 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -104,6 +104,14 @@ void qdev_set_parent_bus(DeviceState *dev, BusState *bus)
     bus_add_child(bus, dev);
 }
 
+static void qdev_unset_parent(DeviceState *dev)
+{
+    BusState *b = dev->parent_bus;
+
+    object_unparent(OBJECT(dev));
+    bus_remove_child(b, dev);
+}
+
 /* Create a new device.  This only initializes the device state structure
    and allows properties to be set.  qdev_init should be called to
    initialize the actual device emulation.  */
@@ -194,6 +202,26 @@ void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,
     dev->alias_required_for_version = required_for_version;
 }
 
+static int qdev_unmap(DeviceState *dev)
+{
+    DeviceClass *dc =  DEVICE_GET_CLASS(dev);
+    if (dc->unmap) {
+        dc->unmap(dev);
+    }
+    return 0;
+}
+
+void qdev_unplug_ack(DeviceState *dev, Error **errp)
+{
+    qemu_rwlock_wrlock_devtree();
+    /* isolate from device tree */
+    qdev_unset_parent(dev);
+    /* isolate from mem view */
+    qdev_unmap(dev);
+    qemu_rwlock_unlock_devtree();
+    object_unref(OBJECT(dev));
+}
+
 void qdev_unplug(DeviceState *dev, Error **errp)
 {
     DeviceClass *dc = DEVICE_GET_CLASS(dev);
diff --git a/hw/qdev.h b/hw/qdev.h
index f4683dc..fc5ff02 100644
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -47,7 +47,7 @@ typedef struct DeviceClass {
 
     /* callbacks */
     void (*reset)(DeviceState *dev);
-
+    void (*unmap)(DeviceState *dev);
     /* device state */
     const VMStateDescription *vmsd;
 
@@ -162,6 +162,7 @@ void qdev_init_nofail(DeviceState *dev);
 void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,
                                  int required_for_version);
 void qdev_unplug(DeviceState *dev, Error **errp);
+void qdev_unplug_ack(DeviceState *dev, Error **errp);
 void qdev_free(DeviceState *dev);
 int qdev_simple_unplug_cb(DeviceState *dev);
 void qdev_machine_creation_done(void);
-- 
1.7.4.4