Allow specification of domain shares (#925)

Weighted priority of the domain relative to others on the host.

README.md

@@ -295,6 +295,7 @@ end
   you create a domain value by default virtio KVM believe possible values, see
   the [documentation for
   Libvirt](https://libvirt.org/formatdomain.html#elementsNICSModel).
+* `shares` - Proportional weighted share for the domain relative to others. For more details see [documentation](https://libvirt.org/formatdomain.html#elementsCPUTuning).
 * `memory` - Amount of memory in MBytes. Defaults to 512 if not set.
 * `cpus` - Number of virtual cpus. Defaults to 1 if not set.
 * `cpuset` - Physical cpus to which the vcpus can be pinned. For more details see [documentation](https://libvirt.org/formatdomain.html#elementsCPUAllocation).

lib/vagrant-libvirt/action/create_domain.rb

@@ -39,6 +39,7 @@ module VagrantPlugins
           @nodeset = config.nodeset
           @features = config.features
           @features_hyperv = config.features_hyperv
+          @shares = config.shares
           @cpu_mode = config.cpu_mode
           @cpu_model = config.cpu_model
           @cpu_fallback = config.cpu_fallback
@@ -213,6 +214,9 @@ module VagrantPlugins
           @memory_backing.each do |backing|
             env[:ui].info(" -- Memory Backing:    #{backing[:name]}: #{backing[:config].map { |k,v| "#{k}='#{v}'"}.join(' ')}")
           end
+          unless @shares.nil?
+            env[:ui].info(" -- Shares:            #{@shares}")
+          end
           env[:ui].info(" -- Management MAC:    #{@management_network_mac}")
           env[:ui].info(" -- Loader:            #{@loader}")
           env[:ui].info(" -- Nvram:             #{@nvram}")

lib/vagrant-libvirt/config.rb

@@ -79,6 +79,7 @@ module VagrantPlugins
       attr_accessor :cpu_fallback
       attr_accessor :cpu_features
       attr_accessor :cpu_topology
+      attr_accessor :shares
       attr_accessor :features
       attr_accessor :features_hyperv
       attr_accessor :numa_nodes
@@ -204,6 +205,7 @@ module VagrantPlugins
         @cpu_fallback      = UNSET_VALUE
         @cpu_features      = UNSET_VALUE
         @cpu_topology      = UNSET_VALUE
+        @shares            = UNSET_VALUE
         @features          = UNSET_VALUE
         @features_hyperv   = UNSET_VALUE
         @numa_nodes        = UNSET_VALUE
@@ -689,6 +691,7 @@ module VagrantPlugins
         @cpu_topology = {} if @cpu_topology == UNSET_VALUE
         @cpu_fallback = 'allow' if @cpu_fallback == UNSET_VALUE
         @cpu_features = [] if @cpu_features == UNSET_VALUE
+        @shares = nil if @shares == UNSET_VALUE
         @features = ['acpi','apic','pae'] if @features == UNSET_VALUE
         @features_hyperv = [] if @features_hyperv == UNSET_VALUE
         @numa_nodes = @numa_nodes == UNSET_VALUE ? nil : _generate_numa

lib/vagrant-libvirt/templates/domain.xml.erb

@@ -45,6 +45,11 @@
   <% end %>
   </memoryBacking>
 <% end%>
+<% if @shares %>
+  <cputune>
+    <shares><%= @shares %></shares>
+  </cputune>
+<% end %>
 
   <os>
     <% if @machine_type %>

spec/unit/templates/domain_all_settings.xml

@@ -14,6 +14,9 @@
   <numatune>
     <memory nodeset='1-4,^3,6'/>
   </numatune>
+  <cputune>
+    <shares>1024</shares>
+  </cputune>
 
   <os>
         <type arch='x86_64' machine='pc-compatible'>hvm</type>

spec/unit/templates/domain_spec.rb

@@ -76,6 +76,7 @@ describe 'templates/domain' do
 
       domain.qemuargs(value: '-device')
       domain.qemuargs(value: 'dummy-device')
+      domain.shares = '1024'
       domain.cpuset = '1-4,^3,6'
       domain.nodeset = '1-4,^3,6'
     end