The modern-xiafs kernel module has been updated to work with (at least) the 4.7.10 and 4.8.7 versions of the Linux kernel. That code is in the current master, but also lives in the linux-4.7.10 branch.
There’s also a small fix for
mkfs.xiafs – there was a bug with setting the umask (or, at least, there was a typo in the original program and it was trying to set the umask in a totally obsolete way) that made it so any filesystem created with it would have totally open permissions. Now, it uses the default umask like one would expect. This fix has been added to the branches for older kernels as well.
Usual warnings: you’d be crazy to use this on a production box, and while it should work fine it could conceivably blow your computer up or something. Don’t forget the whole 2GB volume/64MB max file size limitation either.