VMware: expose max vCPUs and max memory per ESX host

Expose maximum vCPUs and maximum memory from single ESX host in the
vCenter cluster. This will be used for implementing get_inventory() in
the follow up patch.

Partial-Bug: #1462957

Change-Id: I28e19d46a737ac253718c7c66837bd71b064b0b9

nova/tests/unit/virt/vmwareapi/test_driver_api.py

@@ -2383,7 +2383,8 @@ class VMwareAPIVMTestCase(test.NoDBTestCase,
         service = self._create_service(disabled=False, host='fake-mini')
         mock_service.return_value = service
 
-        fake_stats = {'vcpus': 4, 'mem': {'total': '8194', 'free': '2048'}}
+        fake_stats = {'cpu': {'vcpus': 4},
+                      'mem': {'total': '8194', 'free': '2048'}}
         with test.nested(
             mock.patch.object(vm_util, 'get_stats_from_cluster',
                               side_effect=[vexc.VimConnectionException('fake'),

nova/tests/unit/virt/vmwareapi/test_vm_util.py

@@ -117,10 +117,12 @@ class VMwareVMUtilTestCase(test.NoDBTestCase):
                 num_hosts = 2
             else:
                 num_hosts = 1
-            expected_stats = {'vcpus': num_hosts * 16,
+            expected_stats = {'cpu': {'vcpus': num_hosts * 16,
+                                      'max_vcpus_per_host': 16},
                               'mem': {'total': num_hosts * 4096,
                                       'free': num_hosts * 4096 -
-                                              num_hosts * 512}}
+                                              num_hosts * 512,
+                                      'max_mem_mb_per_host': 4096}}
             self.assertEqual(expected_stats, result)
 
     def test_get_stats_from_cluster_hosts_connected_and_active(self):

nova/virt/vmwareapi/host.py

@@ -84,7 +84,7 @@ class VCState(object):
             self._set_host_enabled(False)
             return data
 
-        data["vcpus"] = stats['vcpus']
+        data["vcpus"] = stats['cpu']['vcpus']
         data["disk_total"] = capacity / units.Gi
         data["disk_available"] = freespace / units.Gi
         data["disk_used"] = data["disk_total"] - data["disk_available"]

nova/virt/vmwareapi/vm_util.py

@@ -1159,8 +1159,10 @@ def get_vm_state(session, instance):
 def get_stats_from_cluster(session, cluster):
     """Get the aggregate resource stats of a cluster."""
     vcpus = 0
+    max_vcpus_per_host = 0
     used_mem_mb = 0
     total_mem_mb = 0
+    max_mem_mb_per_host = 0
     # Get the Host and Resource Pool Managed Object Refs
     prop_dict = session._call_method(vutil,
                                      "get_object_properties_dict",
@@ -1186,12 +1188,16 @@ def get_stats_from_cluster(session, cluster):
                     # The overcommitment ratio is factored in by the scheduler
                     threads = hardware_summary.numCpuThreads
                     vcpus += threads
+                    max_vcpus_per_host = max(max_vcpus_per_host, threads)
                     used_mem_mb += stats_summary.overallMemoryUsage
                     mem_mb = hardware_summary.memorySize // units.Mi
                     total_mem_mb += mem_mb
-    stats = {'vcpus': vcpus,
+                    max_mem_mb_per_host = max(max_mem_mb_per_host, mem_mb)
+    stats = {'cpu': {'vcpus': vcpus,
+                     'max_vcpus_per_host': max_vcpus_per_host},
              'mem': {'total': total_mem_mb,
-                     'free': total_mem_mb - used_mem_mb}}
+                     'free': total_mem_mb - used_mem_mb,
+                     'max_mem_mb_per_host': max_mem_mb_per_host}}
     return stats