[libvirt] [PATCH 0/2] qemu: add new disk type='lun' for bus='virtio'

[Paolo Bonzini]

On 12/23/2011 12:15 AM, Daniel P. Berrange wrote:
> The 'type' attribute refers to how the host emulator deals with the
> disk.
>
> The 'device' attribute refers to what type of device hardware is exposed
> to the guest.
>
> What we're doing here is controlling whether the host emulator allows
> SG_IO. The guest visible device hardware has not changed at all. Thus
> using the 'type' attribute is the correct approach.

You could also say that the host is still accessing the device in the 
same way (via /dev/sdX).  The guest visible device changes because in 
one case it allows SG_IO, in the other it doesn't, even if the host 
device is the same.

Paolo