Ha, I thought kvm was on by default.  Apparently not, qemu -enable-kvm
avoids this issue.

Yes, 0x0000000100000000 with RIP=00000000ffffffe4 is quite suspicious,
especially after the splash screen has been displayed.  Off in the weeds
comes to mind - so I'm guessing corrupted or incorrectly mapped guest
memory?

The git tree is where?  (I just grabbed the tarball)