From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Fri, 22 Feb 2013 13:37:10 +0000 (+0100)
Subject: virtio-blk: fix unplug + virsh reboot
X-Git-Tag: qemu-xen-4.4.0-rc1~6^2~963^2~7
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=69b302b2044a9a0f6d157d25b39a91ff7124c61f;p=qemu-xen.git

virtio-blk: fix unplug + virsh reboot

virtio-blk registers a vmstate change handler. Unfortunately this
handler is not unregistered on unplug, leading to some random
crashes if the system is restarted, e.g. via virsh reboot.
Lets unregister the vmstate change handler if the device is removed.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---

diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index 34913ee40e..f5e6ee90b6 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -36,6 +36,7 @@ typedef struct VirtIOBlock
     VirtIOBlkConf *blk;
     unsigned short sector_mask;
     DeviceState *qdev;
+    VMChangeStateEntry *change;
 #ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
     VirtIOBlockDataPlane *dataplane;
 #endif
@@ -681,7 +682,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk)
     }
 #endif
 
-    qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
+    s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
     s->qdev = dev;
     register_savevm(dev, "virtio-blk", virtio_blk_id++, 2,
                     virtio_blk_save, virtio_blk_load, s);
@@ -702,6 +703,7 @@ void virtio_blk_exit(VirtIODevice *vdev)
     virtio_blk_data_plane_destroy(s->dataplane);
     s->dataplane = NULL;
 #endif
+    qemu_del_vm_change_state_handler(s->change);
     unregister_savevm(s->qdev, "virtio-blk", s);
     blockdev_mark_auto_del(s->bs);
     virtio_cleanup(vdev);