Libvirt is aiming towards implementation of qemu\'s blockdev-add command. Main tracking bz is bug 760547. RHV needs to test the entire block device handling part of its product. Also there may be additional changes recommended such as specification of the entire backing chain in the domain xml.
This bug has not been marked as blocker for oVirt 4.3.0. Since we are releasing it tomorrow, January 29th, this bug has been re-targeted to 4.3.1.
This bug didn't get any attention for a while, we didn't have the capacity to make any progress. If you deeply care about it or want to work on it please assign/target accordingly
ok, closing. Please reopen if still relevant/you want to work on it.