Merge "libvirt: call get_capabilities() with all CPUs online"

nova/tests/unit/virt/libvirt/test_driver.py

@@ -895,6 +895,16 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         )
         mock_supports.assert_called_once_with()
 
+    @mock.patch.object(hardware, 'get_cpu_dedicated_set',
+                       return_value=set([0, 42, 1337]))
+    @mock.patch.object(libvirt_driver.LibvirtDriver,
+                       '_register_all_undefined_instance_details')
+    def test_init_host_topology(self, mock_get_cpu_dedicated_set, _):
+        driver = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        with mock.patch.object(driver.cpu_api, 'power_up') as mock_power_up:
+            driver.init_host('goat')
+            mock_power_up.assert_called_with(set([0, 42, 1337]))
+
     @mock.patch.object(
         libvirt_driver.LibvirtDriver,
         '_register_all_undefined_instance_details',

nova/virt/libvirt/cpu/api.py

@@ -91,7 +91,7 @@ class API(object):
         """
         return Core(i)
 
-    def _power_up(self, cpus: ty.Set[int]) -> None:
+    def power_up(self, cpus: ty.Set[int]) -> None:
         if not CONF.libvirt.cpu_power_management:
             return
         cpu_dedicated_set = hardware.get_cpu_dedicated_set_nozero() or set()
@@ -111,7 +111,7 @@ class API(object):
             return
         pcpus = instance.numa_topology.cpu_pinning.union(
             instance.numa_topology.cpuset_reserved)
-        self._power_up(pcpus)
+        self.power_up(pcpus)
 
     def power_up_for_migration(
         self, dst_numa_info: objects.LibvirtLiveMigrateNUMAInfo
@@ -121,7 +121,7 @@ class API(object):
             pcpus = dst_numa_info.emulator_pins
         for pins in dst_numa_info.cpu_pins.values():
             pcpus = pcpus.union(pins)
-        self._power_up(pcpus)
+        self.power_up(pcpus)
 
     def _power_down(self, cpus: ty.Set[int]) -> None:
         if not CONF.libvirt.cpu_power_management:

nova/virt/libvirt/driver.py

@@ -751,12 +751,31 @@ class LibvirtDriver(driver.ComputeDriver):
                  {'enabled': enabled, 'reason': reason})
         self._set_host_enabled(enabled, reason)
 
+    def _init_host_topology(self):
+        """To work around a bug in libvirt that reports offline CPUs as always
+        being on socket 0 regardless of their real socket, power up all
+        dedicated CPUs (the only ones whose socket we actually care about),
+        then call get_capabilities() to initialize the topology with the
+        correct socket values. get_capabilities()'s implementation will reuse
+        these initial socket value, and avoid clobbering them with 0 for
+        offline CPUs.
+        """
+        cpus = hardware.get_cpu_dedicated_set()
+        if cpus:
+            self.cpu_api.power_up(cpus)
+            self._host.get_capabilities()
+
     def init_host(self, host):
         self._host.initialize()
 
-        self._update_host_specific_capabilities()
+        # NOTE(artom) Do this first to make sure our first call to
-
+        # get_capabilities() happens with all dedicated CPUs online and caches
+        # their correct socket ID. Unused dedicated CPUs will be powered down
+        # further down in this method.
         self._check_cpu_set_configuration()
+        self._init_host_topology()
+
+        self._update_host_specific_capabilities()
 
         self._do_quality_warnings()