libdiskmgt should support blkdev devices
libdiskmgt doesn't handle blkdev very well. It doesn't understand the relationship between blkdev and the drivers using blkdev, so it cannot report controller information for blkdev devices. This causes problems with code assuming that an unknown controller type is a serious issue.
I have reason to believe that this is the issue that some some distros using Caiman as installer have trouble installing on virtio-block devices.