Wasn't TSX completely disabled in all Intel processors because of silicon bugs? If it is enabled in the Skylake E5 Xeon series that Google is rolling out, does it mean the Skylake E5 Xeons are the first processors to have a working TSX implementation?
AIUI that was just certain flavors of Broadwell and possibly all (or maybe just all-released-at-the-time) Haswell chips, so later Broadwell steppings had a working TSX implementation.
(As an example, my Xeon D-1540, a Broadwell-family chip, advertises the TSX bits in CPU feature flags, so it's not errata'd off there.)
