Verified via:

1. Installed 15-current on UTM 4.6.3 (qemu 9.2) and rebooted fine.
2. Rebooted under UTM 4.5.4 and it failed per the bug (this was expected).
3. Rebooted with 4.6.3, rebuilt/installed kernel with patches (needed tweaks).
4. Patched kernel boots fine using both UTM 4.5.4 and 4.6.3.

Needs a code tweak to compile.

@corvink your last comment included "I'm going to test this before merging.". I'm assuming you meant "before accepting" and then I will merge onto main and push the commit.

Address review feedback

@corvink thank you for the reviews. Hopefully these last changes should address all of your feedback.

Address review feedback

Address review feedback

Addressing further review feedback

Thank you for the review feedback. I think I address most of it.

Addressing review feedback from corvink

Here is more context in the related bug:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=203874#c29

Thanks @jpaetzel for the ping. Over the weekend I updated my build systems to facilitate a build/test of this code. One outstanding issue, I've been meaning to circle back with @imp on how we should implement the licensing. I'll send a PM to work it out. I'll let @vbhakta_vmware.com comment on any remaining code changes.

Thanks! Useful and looks good to me.

Per imp, abandon this review as existing license is sufficient.

Looks good to me. I'll get it committed.