class xen-hypervisor::hypervisor {
       [...]
       xen-hypervisor::auto_domains { $domains: }
       [...]
    }

    define xen-hypervisor::auto_domains()
    {
       file { "/etc/xen/auto/${name}.cfg" :
           owner   => root,
           group   => root,
           mode    => 644,
           ensure  => "/etc/xen/domains/${name}.cfg"
       }
    }

    node 'toto' {
       $domains = ["toto", "tata", "titi", "tutu", "tete", "tyty"]
       include xen-hypervisor::hypervisor
    }