Acredito que o comando que você está procurando é dkms status
. por exemplo:
% dkms status
virtualbox, 4.1.18: added
Em outro sistema que possui muito mais módulos DKMS instalados:
% dkms status
fglrx, 8.960, 3.2.0-33-generic-pae, i686: installed
fglrx, 8.960, 3.2.0-34-generic, i686: installed
fglrx, 8.960, 3.2.0-34-generic-pae, i686: installed
fglrx, 8.960, 3.2.0-35-generic, i686: installed
fglrx, 8.960, 3.2.0-35-generic-pae, i686: installed
fglrx, 8.960, 3.2.0-36-generic, i686: installed
fglrx, 8.960, 3.2.0-36-generic-pae, i686: installed
fglrx, 8.960, 3.2.0-37-generic, i686: installed
fglrx, 8.960, 3.2.0-37-generic-pae, i686: installed
fglrx, 8.960, 3.2.0-38-generic, i686: installed
fglrx, 8.960, 3.2.0-38-generic-pae, i686: installed
fglrx, 8.960, 3.2.0-39-generic, i686: installed
fglrx, 8.960, 3.2.0-39-generic-pae, i686: installed
fglrx, 8.960, 3.2.0-40-generic, i686: installed
fglrx, 8.960, 3.2.0-40-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-24-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-24-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-26-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-26-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-27-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-27-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-29-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-29-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-31-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-31-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-32-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-32-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-33-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-33-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-34-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-34-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-35-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-35-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-36-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-36-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-37-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-37-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-38-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-38-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-39-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-39-generic-pae, i686: installed
vboxhost, 4.1.8, 3.2.0-40-generic, i686: installed
vboxhost, 4.1.8, 3.2.0-40-generic-pae, i686: installed
Mais informações sobre o DKMS estão aqui na página de manual .