I encountered the same bug. KVM 85+dfsg-4 appears to fail when switching to VGA while using the KVM modules. Disabling the modules results in a successful boot.
I downgraded KVM to 72+dfsg-5 and everything works as expected. MM -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org