virtio-balloon: Add exit handler, fix memleaks

Add an exit handler that will free up RAM after a virtio-balloon device
is unplugged.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

hw/virtio-balloon.c

@@ -297,3 +297,8 @@ VirtIODevice *virtio_balloon_init(DeviceState *dev)
 
     return &s->vdev;
 }
+
+void virtio_balloon_exit(VirtIODevice *vdev)
+{
+    virtio_cleanup(vdev);
+}

hw/virtio-pci.c

@@ -795,6 +795,15 @@ static int virtio_balloon_init_pci(PCIDevice *pci_dev)
     return 0;
 }
 
+static int virtio_balloon_exit_pci(PCIDevice *pci_dev)
+{
+    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+
+    virtio_pci_stop_ioeventfd(proxy);
+    virtio_balloon_exit(proxy->vdev);
+    return virtio_exit_pci(pci_dev);
+}
+
 static PCIDeviceInfo virtio_info[] = {
     {
         .qdev.name = "virtio-blk-pci",
@@ -869,7 +878,7 @@ static PCIDeviceInfo virtio_info[] = {
         .qdev.alias = "virtio-balloon",
         .qdev.size = sizeof(VirtIOPCIProxy),
         .init      = virtio_balloon_init_pci,
-        .exit      = virtio_exit_pci,
+        .exit      = virtio_balloon_exit_pci,
         .vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET,
         .device_id = PCI_DEVICE_ID_VIRTIO_BALLOON,
         .revision  = VIRTIO_PCI_ABI_VERSION,

hw/virtio.h

@@ -213,6 +213,7 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf);
 void virtio_net_exit(VirtIODevice *vdev);
 void virtio_blk_exit(VirtIODevice *vdev);
 void virtio_serial_exit(VirtIODevice *vdev);
+void virtio_balloon_exit(VirtIODevice *vdev);
 
 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
 	DEFINE_PROP_BIT("indirect_desc", _state, _field, \