[libvirt] Would it make sense to have a <disk device='logicalvolume'>?

[Francesco Pretto]

The questions is this:
1) would it make sense to expose a block device in the host to be
mapped like a "logical volume" in the guest (I mean: not actually
exposing it as a physical disk)?
2) Is there any existing hypervisor that could be made to work like this?

Example scenario:

Just suppose I have a real logical volume in the *host* called
"/dev/mapper/domain0_home" (it could be any block device, but this
would be a real useful configuration). Consider the following
hypothetical libvirt configuration:

<disk type='block' device='lv'>
      <source dev='/dev/mapper/domain0_home'/>
      <target dev='home' bus='virtio'/>
</disk>

'lv' stands for "logicavolume". The block device should be
automatically mapped in the *guest* as "/dev/mapper/home", and not
advertised as a physical disk.