xenapi: Support live migration without pools

Implement blueprint xenapi-live-block-migration.
Add ability to live migrate VMs to hosts that are not
a part of a host aggregate (block migration).

This requires XenServer 6.1/later, or XCP 1.6/later. As
of this change, we still do not support instances with
(nova/cinder) volumes attached. External kernels are also
not supported.

Change-Id: I5feb6756d78804aa37780a7d0cda1600f7060afe

2 files changed, 24 insertions, 13 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 61703318f..1b8115531 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -247,7 +247,7 @@ def _get_image_meta(context, image_ref):
 class ComputeManager(manager.SchedulerDependentManager):
     """Manages the running instances from creation to destruction."""
 
-    RPC_API_VERSION = '1.42'
+    RPC_API_VERSION = '1.43'
 
     def __init__(self, compute_driver=None, *args, **kwargs):
         """Load configuration options and connect to the hypervisor."""
@@ -2181,6 +2181,9 @@ class ComputeManager(manager.SchedulerDependentManager):
                              in) nova.db.sqlalchemy.models.Instance.Id
         :param block_migration: if true, prepare for block migration
         :param disk_over_commit: if true, allow disk over commit
+
+        Returns a mapping of values required in case of block migration
+        and None otherwise.
         """
         if not instance:
             instance = self.db.instance_get(ctxt, instance_id)
@@ -2192,6 +2195,8 @@ class ComputeManager(manager.SchedulerDependentManager):
         finally:
             self.driver.check_can_live_migrate_destination_cleanup(ctxt,
                     dest_check_data)
+        if dest_check_data and 'migrate_data' in dest_check_data:
+            return dest_check_data['migrate_data']
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     def check_can_live_migrate_source(self, ctxt, dest_check_data,
@@ -2261,7 +2266,7 @@ class ComputeManager(manager.SchedulerDependentManager):
             self.driver.pre_block_migration(context, instance, disk)
 
     def live_migration(self, context, dest, block_migration=False,
-                       instance=None, instance_id=None):
+                       instance=None, instance_id=None, migrate_data=None):
         """Executing live migration.
 
         :param context: security context
@@ -2269,6 +2274,7 @@ class ComputeManager(manager.SchedulerDependentManager):
         :param instance: instance dict
         :param dest: destination host
         :param block_migration: if true, prepare for block migration
+        :param migrate_data: implementation specific params
 
         """
         # Get instance for error handling.
@@ -2306,7 +2312,7 @@ class ComputeManager(manager.SchedulerDependentManager):
         self.driver.live_migration(context, instance, dest,
                                    self._post_live_migration,
                                    self.rollback_live_migration,
-                                   block_migration)
+                                   block_migration, migrate_data)
 
     def _post_live_migration(self, ctxt, instance_ref,
                             dest, block_migration=False):
diff --git a/nova/compute/rpcapi.py b/nova/compute/rpcapi.py
index 366eaaacf..c81d75356 100644
--- a/nova/compute/rpcapi.py
+++ b/nova/compute/rpcapi.py
@@ -123,6 +123,7 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
         1.42 - Add reservations arg to prep_resize(), resize_instance(),
                finish_resize(), confirm_resize(), revert_resize() and
                finish_revert_resize()
+        1.43 - Add migrate_data to live_migration()
     '''
 
     BASE_RPC_API_VERSION = '1.0'
@@ -168,14 +169,16 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                   version='1.36')
 
     def check_can_live_migrate_destination(self, ctxt, instance, destination,
-            block_migration, disk_over_commit):
+                                           block_migration, disk_over_commit):
         instance_p = jsonutils.to_primitive(instance)
-        self.call(ctxt, self.make_msg('check_can_live_migrate_destination',
-                           instance=instance_p,
-                           block_migration=block_migration,
-                           disk_over_commit=disk_over_commit),
-                  topic=_compute_topic(self.topic, ctxt, destination, None),
-                  version='1.10')
+        return self.call(ctxt,
+                         self.make_msg('check_can_live_migrate_destination',
+                                       instance=instance_p,
+                                       block_migration=block_migration,
+                                       disk_over_commit=disk_over_commit),
+                         topic=_compute_topic(self.topic,
+                                              ctxt, destination, None),
+                         version='1.10')
 
     def check_can_live_migrate_source(self, ctxt, instance, dest_check_data):
         instance_p = jsonutils.to_primitive(instance)
@@ -283,12 +286,14 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 topic=_compute_topic(self.topic, ctxt, None, instance),
                 version='1.19')
 
-    def live_migration(self, ctxt, instance, dest, block_migration, host):
+    def live_migration(self, ctxt, instance, dest, block_migration, host,
+                       migrate_data=None):
         instance_p = jsonutils.to_primitive(instance)
         self.cast(ctxt, self.make_msg('live_migration', instance=instance_p,
-                dest=dest, block_migration=block_migration),
+                dest=dest, block_migration=block_migration,
+                migrate_data=migrate_data),
                 topic=_compute_topic(self.topic, ctxt, host, None),
-                version='1.40')
+                version='1.43')
 
     def pause_instance(self, ctxt, instance):
         instance_p = jsonutils.to_primitive(instance)