Merge "Fixes NoneType vcpu list returned by Libvirt driver" into stable/havana

2 files changed, 28 insertions, 3 deletions

diff --git a/nova/tests/virt/libvirt/test_libvirt.py b/nova/tests/virt/libvirt/test_libvirt.py
index cd69a83946..3b426cf0bb 100644
--- a/nova/tests/virt/libvirt/test_libvirt.py
+++ b/nova/tests/virt/libvirt/test_libvirt.py
@@ -5174,9 +5174,32 @@ class LibvirtConnTestCase(test.TestCase):
         conn.lookupByID(2).AndReturn(DiagFakeDomain(5))
 
         self.mox.ReplayAll()
-
         self.assertEqual(5, driver.get_vcpu_used())
 
+    def test_failing_vcpu_count_none(self):
+        """Domain will return zero if the current number of vcpus used
+        is None. This is in case of VM state starting up or shutting
+        down. None type returned is counted as zero.
+        """
+
+        class DiagFakeDomain(object):
+            def __init__(self):
+                pass
+
+            def vcpus(self):
+                return None
+
+        driver = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)
+        conn = driver._conn
+        self.mox.StubOutWithMock(driver, 'list_instance_ids')
+        conn.lookupByID = self.mox.CreateMockAnything()
+
+        driver.list_instance_ids().AndReturn([1])
+        conn.lookupByID(1).AndReturn(DiagFakeDomain())
+
+        self.mox.ReplayAll()
+        self.assertEqual(0, driver.get_vcpu_used())
+
     def test_get_instance_capabilities(self):
         conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)
 
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 9abfedef4e..150024e3be 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -3454,7 +3454,7 @@ class LibvirtDriver(driver.ComputeDriver):
     def get_vcpu_used(self):
         """Get vcpu usage number of physical computer.
 
-        :returns: The total number of vcpu that currently used.
+        :returns: The total number of vcpu(s) that are currently being used.
 
         """
 
@@ -3473,7 +3473,9 @@ class LibvirtDriver(driver.ComputeDriver):
                                " %(id)s, exception: %(ex)s") %
                                {"id": dom_id, "ex": e})
                 else:
-                    total += len(vcpus[1])
+                    if vcpus is not None and len(vcpus) > 1:
+                        total += len(vcpus[1])
+
             except exception.InstanceNotFound:
                 LOG.info(_("libvirt can't find a domain with id: %s") % dom_id)
                 continue