From fe25fa13e0572aafb62b28bf7fa843a1860e5010 Mon Sep 17 00:00:00 2001
From: Sean Mooney <work@seanmooney.info>
Date: Wed, 6 Jan 2021 18:56:39 +0000
Subject: [PATCH] Test numa and vcpu topologies bug: #1910466

This change reproduces bug #1910466
When hw:cpu_max_[sockets|cores|threads] is configured
in addition to an explict numa topologies and cpu pinning
nova is currently incapable of generating the correct
virtual CPU topology resulting in an index out of range
error as we attempt to retrieve the first topology
from an empty list.

This change reproduces the error via a new functional
test.

Related-Bug: #1910466
Change-Id: I333b3d85deed971678141307dd06545e308cf989
---
 .../functional/libvirt/test_numa_servers.py   | 39 ++++++++++++++++++-
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/nova/tests/functional/libvirt/test_numa_servers.py b/nova/tests/functional/libvirt/test_numa_servers.py
index 4f8f78a6bb..a3f35b0c68 100644
--- a/nova/tests/functional/libvirt/test_numa_servers.py
+++ b/nova/tests/functional/libvirt/test_numa_servers.py
@@ -103,8 +103,8 @@ class NUMAServersTest(NUMAServersTestBase):
         nodes.
         """
 
-        host_info = fakelibvirt.HostInfo(cpu_nodes=2, cpu_sockets=1,
-                                         cpu_cores=2, cpu_threads=2)
+        host_info = fakelibvirt.HostInfo(
+            cpu_nodes=2, cpu_sockets=1, cpu_cores=2, cpu_threads=2)
         self.start_compute(host_info=host_info, hostname='compute1')
 
         extra_spec = {'hw:numa_nodes': '2'}
@@ -119,6 +119,41 @@ class NUMAServersTest(NUMAServersTestBase):
         self.assertNotIn('cpu_topology', inst.numa_topology.cells[0])
         self.assertNotIn('cpu_topology', inst.numa_topology.cells[1])
 
+    def test_create_server_with_numa_topology_and_cpu_topology_and_pinning(
+            self):
+        """Create a server with two NUMA nodes.
+
+        This should pass and result in a guest NUMA topology with two NUMA
+        nodes, pinned cpus and numa affined memory.
+        """
+
+        host_info = fakelibvirt.HostInfo(
+            cpu_nodes=2, cpu_sockets=1, cpu_cores=4, cpu_threads=1,
+            kB_mem=(1024 * 1024 * 16))  # 16 GB
+        self.start_compute(host_info=host_info, hostname='compute1')
+
+        extra_spec = {
+            'hw:numa_nodes': '2',
+            'hw:cpu_max_sockets': '2',
+            'hw:cpu_max_cores': '2',
+            'hw:cpu_max_threads': '8',
+            'hw:cpu_policy': 'dedicated',
+            'hw:mem_page_size': 'any'
+        }
+        flavor_id = self._create_flavor(vcpu=8, extra_spec=extra_spec)
+        self._run_build_test(flavor_id, end_status='ERROR')
+
+        # FIXME(sean-k-mooney): The instance should boot but
+        # it fails due to https://bugs.launchpad.net/nova/+bug/1910466
+        msg = "IndexError: list index out of range"
+        self.assertIn(msg, self.stdlog.logger.output)
+        # ctx = nova_context.get_admin_context()
+        # inst = objects.Instance.get_by_uuid(ctx, server['id'])
+        # self.assertEqual(2, len(inst.numa_topology.cells))
+        # self.assertLessEqual(inst.vcpu_model.topology.sockets, 2)
+        # self.assertLessEqual(inst.vcpu_model.topology.cores, 2)
+        # self.assertLessEqual(inst.vcpu_model.topology.threads, 8)
+
     def test_create_server_with_numa_fails(self):
         """Create a two NUMA node instance on a host with only one node.