Enable higher performance I/O through

In Ubuntu 16.04 the updated kernel that is shipped has conntrack support.
The inclusion of conntrack led to a new firewall driver that removed the
need for hybrid vif plugging. Hybrid vif plugging allowed security groups
to operate properly, but led to significant performance degradation's
when paired with OVS.

Since the inclusion of OVS for the PowerVM driver occurred during the
OpenStack Newton release, it aligned well with the Ubuntu 16.04 release.
As such, the PowerVM driver team did not enable hybrid vif plugging, but
instead focused on standard plugging.

This change set allows an option to turn off the hybrid vif plugging
(for all architectures), but will automatically detect it for PowerVM
and turn it off.  This will enable deployments on newer operating systems
to have higher network I/O performance.

Change-Id: I0801b0d6925a0d3c0ae9b14d38310d5906355b98
Partially-Implements: blueprint powervm-virt-driver

releasenotes/notes/neutron-ovs-powervm-116662f169e17175.yaml

@@ -0,0 +1,18 @@
+---
+features:
+  - |
+    The ``os_neutron`` role will now default to the OVS firewall driver when
+    ``neutron_plugin_type`` is ``ml2.ovs`` and the host is running Ubuntu
+    16.04 on PowerVM. To override this default behavior, deployers should
+    define ``neutron_ml2_conf_ini_overrides`` and
+    'neutron_openvswitch_agent_ini_overrides' in 'user_variables.yml'. Example
+    below
+
+    ::
+
+      neutron_ml2_conf_ini_overrides:
+        securitygroup:
+          firewall_driver: neutron.agent.linux.iptables_firewall.OVSHybridIptablesFirewallDriver
+      neutron_openvswitch_agent_ini_overrides:
+        securitygroup:
+          firewall_driver: iptables_hybrid

tasks/main.yml

@@ -36,6 +36,32 @@
   tags:
     - always
 
+- name: Get CPU info content and store as var
+  shell: cat /proc/cpuinfo
+  register: cpuinfo_contents
+  changed_when: false
+  failed_when: false
+  tags:
+    - always
+
+- name: Set neutron target platform type
+  set_fact:
+    neutron_os_type: "powervm"
+  when:
+    - cpuinfo_contents.stdout.find('pSeries') != -1
+    - ansible_architecture == 'ppc64le'
+  tags:
+    - always
+
+- include: neutron_ml2_ovs_powervm.yml
+  when:
+    - neutron_os_type is defined
+    - neutron_os_type == 'powervm'
+    - neutron_plugin_type == 'ml2.ovs'
+    - "{{ ansible_distribution_version | version_compare('16.04','>=') }}"
+  tags:
+    - neutron-config
+
 - include: neutron_check.yml
   tags:
     - always

tasks/neutron_ml2_ovs_powervm.yml

@@ -0,0 +1,26 @@
+---
+# Copyright 2016, IBM Corp.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+- name: Override neutron ovs driver firewall type
+  set_fact:
+    neutron_ml2_conf_ini_overrides:
+      securitygroup:
+        firewall_driver: "openvswitch"
+
+- name: Override neutron ovs driver firewall
+  set_fact:
+    neutron_openvswitch_agent_ini_overrides:
+      securitygroup:
+        firewall_driver: "neutron.agent.linux.openvswitch_firewall.OVSFirewallDriver"