Add memory transfer progress info to migration

* hypervisor/hv_kvm.py
  - parse the memory transfer status

* cmdlib.py
  - represent memory transfer info, if available
Signed-off-by: Andrea Spadaccini <spadaccio@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

lib/cmdlib.py

@@ -7027,7 +7027,8 @@ class TLMigrateInstance(Tasklet):
   """
 
   # Constants
-  _MIGRATION_POLL_INTERVAL = 0.5
+  _MIGRATION_POLL_INTERVAL = 1      # seconds
+  _MIGRATION_FEEDBACK_INTERVAL = 10 # seconds
 
   def __init__(self, lu, instance_name, cleanup=False,
                failover=False, fallback=False,
@@ -7445,6 +7446,7 @@ class TLMigrateInstance(Tasklet):
                                (instance.name, msg))
 
     self.feedback_fn("* starting memory transfer")
+    last_feedback = time.time()
     while True:
       result = self.rpc.call_instance_get_migration_status(source_node,
                                                            instance)
@@ -7463,6 +7465,13 @@ class TLMigrateInstance(Tasklet):
         self.feedback_fn("* memory transfer complete")
         break
 
+      if (utils.TimeoutExpired(last_feedback,
+                               self._MIGRATION_FEEDBACK_INTERVAL) and
+          ms.transferred_ram is not None):
+        mem_progress = 100 * float(ms.transferred_ram) / float(ms.total_ram)
+        self.feedback_fn("* memory transfer progress: %.2f %%" % mem_progress)
+        last_feedback = time.time()
+
       time.sleep(self._MIGRATION_POLL_INTERVAL)
 
     result = self.rpc.call_instance_finalize_migration_src(source_node,

lib/hypervisor/hv_kvm.py

@@ -476,6 +476,11 @@ class KVMHypervisor(hv_base.BaseHypervisor):
 
   _MIGRATION_STATUS_RE = re.compile("Migration\s+status:\s+(\w+)",
                                     re.M | re.I)
+  _MIGRATION_PROGRESS_RE = re.compile(
+      "\s*transferred\s+ram:\s+(?P<transferred>\d+)\s+kbytes\s*\n"
+      "\s*remaining\s+ram:\s+(?P<remaining>\d+)\s+kbytes\s*\n"
+      "\s*total\s+ram:\s+(?P<total>\d+)\s+kbytes\s*\n", re.I)
+
   _MIGRATION_INFO_MAX_BAD_ANSWERS = 5
   _MIGRATION_INFO_RETRY_DELAY = 2
 
@@ -1683,6 +1688,11 @@ class KVMHypervisor(hv_base.BaseHypervisor):
         status = match.group(1)
         if status in constants.HV_KVM_MIGRATION_VALID_STATUSES:
           migration_status = objects.MigrationStatus(status=status)
+          match = self._MIGRATION_PROGRESS_RE.search(result.stdout)
+          if match:
+            migration_status.transferred_ram = match.group("transferred")
+            migration_status.total_ram = match.group("total")
+
           return migration_status
 
         logging.warning("KVM: unknown migration status '%s'", status)