Forgot to Cc these to Thomas - let me forward them to ask his input.
Thomas - do these look good to you? 4.14 is a little different in the sense that it didn't have the x86 set-affinity-before-activate workaround. It did have the same failure scenario that was seen on arm64, so the patches are necessary.
The x86 irq allocation loop has some differences for 4.14 x86 too, but I don't see any problems there.
I tested this backport by running it through our regression tests and the reproducer case for the original problem.
Thanks,
- Frank