The virt-who package allows you to map virtual machines to the physical host so that you can take advantage of RedHat Virtual Data Center licensing when using Satellite 6.1. It allows you to use your Hypervisor Host (in this case VMware ESXi) as a content host within Satellite. Therefore allowing you to assign RHEL licenses to the hosts directly, rather than individually on the virtual machine.

To do this, I’m going to leverage Puppet. In my puppet manifest I have:
file { '/etc/virt-who.d/vcenter.conf':
ensure => file,
owner => 'root',
mode => 644,
group => 'root',
source => "puppet:///modules/profiles/center"
}
And on the puppet server in: /etc/puppet/modules/profiles/files/

I have a file called vcenter, it looks like this:
[vcenter.domain.internal]
type=esx
server=vcenter.domain.internal
username=administrator@domain.internal.vmw
password=Password1!
#encryped_password=
owner="1"
env=Library
hypervisor_id=hostname
With this configuration, my ESX hosts will show up under Satellite > Hosts > Content Hosts

Here you can see that Satellite now can identify the VM’s then running on the Hypervisor Host