diff --git a/nova/virt/driver.py b/nova/virt/driver.py
index 34ce9613b76..200bada2979 100644
--- a/nova/virt/driver.py
+++ b/nova/virt/driver.py
@@ -22,9 +22,17 @@
     types that support that contract
 """
 
+from nova import context as nova_context
+from nova import db
+from nova import flags
+from nova import log as logging
 from nova.compute import power_state
 
 
+LOG = logging.getLogger("nova.virt.driver")
+FLAGS = flags.FLAGS
+
+
 class InstanceInfo(object):
     def __init__(self, name, state):
         self.name = name
@@ -500,7 +508,7 @@ def poll_rescued_instances(self, timeout):
         raise NotImplementedError()
 
     def poll_unconfirmed_resizes(self, resize_confirm_window):
-        """Poll for unconfirmed resizes"""
+        """Poll for unconfirmed resizes."""
         # TODO(Vek): Need to pass context in for access to auth_token
         raise NotImplementedError()
 
diff --git a/nova/virt/libvirt/connection.py b/nova/virt/libvirt/connection.py
index 9f8971295d7..7caee1eb84b 100644
--- a/nova/virt/libvirt/connection.py
+++ b/nova/virt/libvirt/connection.py
@@ -688,7 +688,25 @@ def poll_rescued_instances(self, timeout):
 
     @exception.wrap_exception()
     def poll_unconfirmed_resizes(self, resize_confirm_window):
-        pass
+        """Poll for unconfirmed resizes.
+
+        Look for any unconfirmed resizes that are older than
+        `resize_confirm_window` and automatically confirm them.
+        """
+        ctxt = nova_context.get_admin_context()
+        migrations = db.migration_get_all_unconfirmed(ctxt,
+            resize_confirm_window)
+
+        migrations_info = dict(migration_count=len(migrations),
+                confirm_window=FLAGS.resize_confirm_window)
+
+        if migrations_info["migration_count"] > 0:
+            LOG.info(_("Found %(migration_count)d unconfirmed migrations "
+                    "older than %(confirm_window)d seconds") % migrations_info)
+
+        for migration in migrations:
+            LOG.info(_("Automatically confirming migration %d"), migration.id)
+            self.compute_api.confirm_resize(ctxt, migration.instance_uuid)
 
     # NOTE(ilyaalekseyev): Implementation like in multinics
     # for xenapi(tr3buchet)