Comment 10 for bug 1922907

That tsx issue is orthogonal to the sky-/cascade-lake detection.
It is due to all the spectre/meltdown/l1tf/... fixes, one of them had to more or less turn TSX off (by default) and is discussed in 1853200. There isn't a neat works-for-all solution yet - and admins have to decide to either adapt guest definitions (and other software using TSX) OR to opt into using TSX as you've done with the kernel cmdline.

But to be sure, was this - for you - only the tsx mismatch all along. Which means does this work fine for you with just the kernel cmdline but without the build that I provided?
Or do you need both to get it going?