remove db access in xen driver.

fix bug 1081949

Change-Id: I0b0369921b974d068b92c90db8b3cf0ae396cc2d

nova/virt/xenapi/vm_utils.py

@@ -35,7 +35,6 @@
 from eventlet import greenthread
 
 from nova import block_device
-from nova.compute import instance_types
 from nova.compute import power_state
 from nova import exception
 from nova.image import glance
@@ -204,8 +203,7 @@ def create_vm(session, instance, name_label, kernel, ramdisk,
 
         3. Using hardware virtualization
     """
-    inst_type_id = instance['instance_type_id']
-    instance_type = instance_types.get_instance_type(inst_type_id)
+    instance_type = instance['instance_type']
     mem = str(long(instance_type['memory_mb']) * 1024 * 1024)
     vcpus = str(instance_type['vcpus'])
 
@@ -320,7 +318,7 @@ def _is_vm_shutdown(session, vm_ref):
 
 def ensure_free_mem(session, instance):
     inst_type_id = instance['instance_type_id']
-    instance_type = instance_types.get_instance_type(inst_type_id)
+    instance_type = instance['instance_type']
     mem = long(instance_type['memory_mb']) * 1024 * 1024
     host = session.get_xenapi_host()
     host_free_mem = long(session.call_xenapi("host.compute_free_memory",
@@ -1139,8 +1137,7 @@ def _check_vdi_size(context, session, instance, vdi_uuid):
 
     # FIXME(jk0): this was copied directly from compute.manager.py, let's
     # refactor this to a common area
-    instance_type_id = instance['instance_type_id']
-    instance_type = instance_types.get_instance_type(instance_type_id)
+    instance_type = instance['instance_type']
     allowed_size_gb = instance_type['root_gb']
     allowed_size_bytes = allowed_size_gb * 1024 * 1024 * 1024