On 12/23/2011 01:42 AM, Paolo Bonzini wrote:
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.
I also tend to agree that 1) this is a guest-visible change in behavior for the same host resource, and 2) Paolo's proposals for virtio-scsi LUN pass-through present device='lun'. https://www.redhat.com/archives/libvir-list/2011-December/msg01013.html Or do we mix the two concepts? That is, type='lun' is used to control SG_IO enabling, while device='lun' is used to control LUN pass-through, and you can even have the combination type='lun' device='lun'? -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org