Vitaly Chipounov has released PyKVM on the S2E-dev mailing list:
It is my pleasure to announce PyKVM, a tiny KVM client written in
Python. PyKVM lets you efficiently symbolically execute binaries that
don’t interact with the OS and don’t need virtual hardware. There is no
hardware to emulate and no OS to run, which removes all the unnecessary
overhead. You can also reuse your Python-based program analysis tools,
which can easily access the concrete state of the VM. Finally, you can
get a better understanding of how KVM works in very little code.
This client is compatible with the KVM extensions for symbolic execution provided by S2E. In other words, you can symbolically execute programs with PyKVM.