create tap = True and allow nested VMs on all vifib servers

this is needed for all servers hosting VMs. As we don't really know which server are hosting VM, we do it on all vifib servers.

/cc @alain.takoudjou @rafael @guillaume.hervier

/reviewed-on nexedi/slapos.package!82

playbook/roles/vifib-server/tasks/kvm.yml

 ---
 
-  - modprobe: name=kvm_intel state=present
+  - modprobe: name=kvm_intel state=present params='nested=Y'
     ignore_errors: True
 
   - pause: seconds=2
@@ -24,3 +24,11 @@
   - name: Set 666 on /dev/vhost-net
     shell: chmod 666 /dev/vhost-net           
     when: dev_vhost.stat.exists == True
+
+  - name: Check if configuration exists already
+    stat: path=/etc/opt/slapos/slapos.cfg
+    register: xslapos_cfg
+
+  - name: Force create_tap to be true
+    shell: sed -i 's/^create_tap =.*/create_tap = True/' /etc/opt/slapos/slapos.cfg
+    when: xslapos_cfg.stat.exists == True