I want a KVM guest with SDL graphics on a host that does not run X. From what I've read, SDL supports output to the framebuffer, but I can't find much on the topic.
You need to check if the applications developed in SDL implemented this feature because it's not automatic. (for example, vlc --vout fb)
If it concerns one of your project, this page shows how to develop SDL using FB : http://www.libsdl.org/intro.en/usingvideo.html