Add support for spinlocks hyperv feature

lib/vagrant-libvirt/action/create_domain.rb

@@ -237,7 +237,11 @@ module VagrantPlugins
             env[:ui].info(" -- Feature:           #{feature}")
           end
           @features_hyperv.each do |feature|
-            env[:ui].info(" -- Feature (HyperV):  name=#{feature[:name]}, state=#{feature[:state]}")
+            if feature[:name] == 'spinlocks'
+              env[:ui].info(" -- Feature (HyperV):  name=#{feature[:name]}, state=#{feature[:state]}, retries=#{feature[:retries]}")
+            else
+              env[:ui].info(" -- Feature (HyperV):  name=#{feature[:name]}, state=#{feature[:state]}")
+            end
           end
           env[:ui].info(" -- Clock offset:      #{@clock_offset}")
           @clock_timers.each do |timer|

lib/vagrant-libvirt/config.rb

@@ -398,10 +398,20 @@ module VagrantPlugins
           raise 'Feature name AND state must be specified'
         end
 
+        if options[:name] == 'spinlocks' && options[:retries].nil?
+          raise 'Feature spinlocks requires retries parameter'
+        end
+
         @features_hyperv = []  if @features_hyperv == UNSET_VALUE
 
-        @features_hyperv.push(name: options[:name],
-                              state: options[:state])
+        if options[:name] == 'spinlocks'
+          @features_hyperv.push(name:   options[:name],
+                             state: options[:state],
+                             retries: options[:retries])
+        else
+          @features_hyperv.push(name:   options[:name],
+                             state: options[:state])
+        end
       end
 
       def clock_timer(options = {})

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

@@ -99,7 +99,7 @@
     <% if !@features_hyperv.empty? %>
     <hyperv>
       <% @features_hyperv.each do |feature| %>
-      <<%= feature[:name] %> state='<%= feature[:state] %>' />
+      <<%= feature[:name] %> state='<%= feature[:state] %>'<% if feature[:name] == 'spinlocks' %> retries='<%= feature[:retries] %>'<% end %> />
       <% end %>
     </hyperv>
     <% end %>