Enable KSM support for Nova

Change-Id: I6515354a3ceb7f08a647a3e0b93ab06ad24e209c

defaults/main.yml

@@ -176,6 +176,9 @@ nova_virt_types:
 # If this is not set, then the playbook will try to guess it.
 #nova_virt_type: kvm
 
+# Enable Kernel Shared Memory (KSM)
+nova_compute_ksm_enabled: False
+
 #if set, nova_virt_type must be one of these:
 nova_supported_virt_types:
   - qemu

releasenotes/notes/support-ksm-fe6993158768a14e.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Enable Kernel Shared Memory support by setting
+    ``nova_compute_ksm_enabled`` to ``True``.

tasks/drivers/kvm/nova_compute_kvm.yml

@@ -119,6 +119,12 @@
   tags:
     - nova-config
 
+- include: nova_enable_ksm.yml
+  when:
+    - nova_compute_ksm_enabled | bool
+  tags:
+    - nova-config
+
 - include: nova_compute_kvm_virsh_net_remove.yml
   tags:
     - nova-config

tasks/drivers/kvm/nova_enable_ksm.yml

@@ -0,0 +1,14 @@
+---
+- name: Enable ksm systemd service
+  service:
+    name: ksm
+    enabled: yes
+    state: started
+
+- name: Enable ksmtuned systemd service
+  service:
+    name: ksmtuned
+    enabled: yes
+    state: started
+  when:
+    - ansible_pkg_mgr in ['yum', 'dnf', 'apt']

vars/main.yml

@@ -31,6 +31,9 @@ nova_package_list: |-
   {% if 'nova_compute' in group_names %}
   {%   if nova_virt_type in ['kvm', 'qemu'] %}
   {%     set _ = packages.extend(nova_compute_kvm_distro_packages) %}
+  {%     if nova_compute_ksm_enabled %}
+  {%       set _ = packages.extend(nova_compute_ksm_packages) %}
+  {%     endif %}
   {%   elif nova_virt_type == 'lxd' %}
   {%     set _ = packages.extend(nova_compute_lxd_distro_packages) %}
   {%   elif nova_virt_type == 'powervm' %}

vars/redhat-7.yml

@@ -60,6 +60,9 @@ nova_compute_kvm_distro_packages:
   - qemu-img-ev
   - sysfsutils
 
+nova_compute_ksm_packages:
+  - ksmtuned
+
 # TODO: add support for LXD on CentOS at some point.
 nova_compute_lxd_distro_packages: []
 

vars/suse-42.yml

@@ -53,6 +53,9 @@ nova_compute_kvm_distro_packages:
   - qemu-tools
   - sysfsutils
 
+nova_compute_ksm_packages:
+  - qemu-ksm
+
 # TODO: add support for LXD on openSUSE at some point.
 nova_compute_lxd_distro_packages: []
 

vars/ubuntu-16.04.yml

@@ -101,6 +101,9 @@ nova_compute_powervm_distro_packages:
   - multipath-tools
   - pvm-novalink
 
+nova_compute_ksm_packages:
+  - ksmtuned
+
 novalink_repo:
   repo: "deb [arch=ppc64el] http://public.dhe.ibm.com/systems/virtualization/Novalink/debian/ novalink_1.0.0 non-free"
   state: "present"