From 4ae1ad5e2bc60c2911fda9bdf38044251e91b6ab Mon Sep 17 00:00:00 2001
From: Nikola Dipanov <ndipanov@redhat.com>
Date: Wed, 16 Jul 2014 17:00:50 +0200
Subject: [PATCH] libvirt: Add method for getting host NUMA topology

We can get this information from the libvirt capabilities XML now, so we
add a method that returns it in the form of
virt.hardware.VirtNUMATopology objects. We will exclude any CPUs not
found in the CONF.vcpu_pin_set.

Change-Id: Ibfc60bc71e49579bc5ab4996b752ed7a49830b6a
Blueprint: virt-driver-numa-placement
---
 nova/tests/virt/libvirt/test_driver.py | 67 ++++++++++++++++++++++++++
 nova/virt/libvirt/driver.py            | 19 ++++++++
 2 files changed, 86 insertions(+)

diff --git a/nova/tests/virt/libvirt/test_driver.py b/nova/tests/virt/libvirt/test_driver.py
index 1d49afebe87d..f59faf026ceb 100644
--- a/nova/tests/virt/libvirt/test_driver.py
+++ b/nova/tests/virt/libvirt/test_driver.py
@@ -78,6 +78,7 @@ from nova.virt import driver
 from nova.virt import event as virtevent
 from nova.virt import fake
 from nova.virt import firewall as base_firewall
+from nova.virt import hardware
 from nova.virt import images
 from nova.virt.libvirt import blockinfo
 from nova.virt.libvirt import config as vconfig
@@ -6899,6 +6900,72 @@ class LibvirtConnTestCase(test.TestCase,
             if key not in ['phys_function', 'virt_functions', 'label']:
                 self.assertEqual(actctualvfs[0][key], expectvfs[1][key])
 
+    def test_get_host_numa_topology(self):
+        caps = vconfig.LibvirtConfigCaps()
+        caps.host = vconfig.LibvirtConfigCapsHost()
+        caps.host.topology = vconfig.LibvirtConfigCapsNUMATopology()
+
+        cell_0 = vconfig.LibvirtConfigCapsNUMACell()
+        cell_0.id = 0
+        cell_0.memory = 512
+        cpu_0_0 = vconfig.LibvirtConfigCapsNUMACPU()
+        cpu_0_0.id = 0
+        cpu_0_0.socket_id = 0
+        cpu_0_0.core_id = 0
+        cpu_0_0.sibling = 0
+        cpu_0_1 = vconfig.LibvirtConfigCapsNUMACPU()
+        cpu_0_1.id = 1
+        cpu_0_1.socket_id = 0
+        cpu_0_1.core_id = 1
+        cpu_0_1.sibling = 1
+        cell_0.cpus = [cpu_0_0, cpu_0_1]
+
+        cell_1 = vconfig.LibvirtConfigCapsNUMACell()
+        cell_1.id = 1
+        cell_1.memory = 512
+        cpu_1_0 = vconfig.LibvirtConfigCapsNUMACPU()
+        cpu_1_0.id = 2
+        cpu_1_0.socket_id = 1
+        cpu_1_0.core_id = 0
+        cpu_1_0.sibling = 2
+        cpu_1_1 = vconfig.LibvirtConfigCapsNUMACPU()
+        cpu_1_1.id = 3
+        cpu_1_1.socket_id = 1
+        cpu_1_1.core_id = 1
+        cpu_1_1.sibling = 3
+        cell_1.cpus = [cpu_1_0, cpu_1_1]
+
+        caps.host.topology.cells = [cell_0, cell_1]
+
+        conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        expected_topo_dict = {'cells': [
+                                {'cpus': '0,1', 'cpu_usage': 0,
+                                  'mem': {'total': 512, 'used': 0},
+                                  'id': 0},
+                                {'cpus': '3', 'cpu_usage': 0,
+                                  'mem': {'total': 512, 'used': 0},
+                                  'id': 1}]}
+        with contextlib.nested(
+                mock.patch.object(
+                    conn, '_get_host_capabilities', return_value=caps),
+                mock.patch.object(
+                    hardware, 'get_vcpu_pin_set', return_value=set([0, 1, 3]))
+                ):
+            got_topo = conn._get_host_numa_topology()
+            got_topo_dict = got_topo._to_dict()
+            self.assertThat(
+                    expected_topo_dict, matchers.DictMatches(got_topo_dict))
+
+    def test_get_host_numa_topology_empty(self):
+        caps = vconfig.LibvirtConfigCaps()
+        caps.host = vconfig.LibvirtConfigCapsHost()
+        caps.host.topology = None
+
+        conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        with mock.patch.object(
+                conn, '_get_host_capabilities', return_value=caps):
+            self.assertIsNone(conn._get_host_numa_topology())
+
     def test_diagnostic_vcpus_exception(self):
         xml = """
                 <domain type='kvm'>
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index e2454efe9c1e..1d226e3b16fb 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -4427,6 +4427,25 @@ class LibvirtDriver(driver.ComputeDriver):
 
         return jsonutils.dumps(pci_info)
 
+    def _get_host_numa_topology(self):
+        caps = self._get_host_capabilities()
+        topology = caps.host.topology
+
+        if topology is None or not topology.cells:
+            return
+
+        topology = hardware.VirtNUMAHostTopology(
+                cells=[hardware.VirtNUMATopologyCellUsage(
+                            cell.id, set(cpu.id for cpu in cell.cpus),
+                            cell.memory)
+                       for cell in topology.cells])
+
+        allowed_cpus = hardware.get_vcpu_pin_set()
+        if allowed_cpus:
+            for cell in topology.cells:
+                cell.cpuset &= allowed_cpus
+        return topology
+
     def get_all_volume_usage(self, context, compute_host_bdms):
         """Return usage info for volumes attached to vms on
            a given host.