Comment # 11 on bug 1091097 from Michal Kube��ek

(In reply to Fabian Vogt from comment #10)
> IMO kernel-default-base should be the same as kernel-default but just exclude
> support for physical hardware. Anything else is just asking for trouble.
> I can definitely see use-cases for 9pfs in production.

Sounds like you are still assuming kernel-*-base subpackage was designed for
use in general purpose VMs. AFAIK this is not true, even package description
says something very different. What you want is rather closer to -ec2 flavor
we have had earlier or kvmsmall config recently introduced in newer branches
(it is meant for developer use but it's probably closer to your idea what
-base subpackage should be than actual -base). Therefore my suggestions from
comment 7.