Security News > 2021 > June > Intel sticks another nail in the coffin of TSX with feature-disabling microcode update

A year later, in 2014, Intel was forced to turn TSX off in Haswell and selected Broadwell chips after an erratum was disclosed allowing for "Unpredictable system behaviour" - exactly the opposite of what you want in your database-centric server system.

It would now appear that Intel plans to throw in the towel, as brought to our attention in a scan of the latest changes to the Linux kernel by Phoronix: Intel has released a microcode update which disables TSX on processors ranging from the Broadwell successor Skylake through to Coffee Lake parts released starting in 2017.

The company had previously been focused on workarounds and it's only in an update released this month that it has admitted defeat and announced "Client Intel TSX changes" which effectively turn the feature off for good.

"Note that for the affected Intel Xeon Processor E3 v5 and v6 Family and the 6th, 7th, and 8th Generation Intel Core i7 and i5, a newer microcode update will be released in 2021.1 IPU that will disable Intel TSX by default," Intel wrote by way of warning.

These already come with mitigations for security concerns in the TSX instructions which have a corresponding impact on performance - though not as severe as turning TSX off entirely - while the company's newest 10th-generation Comet Lake and Ice Lake and 11th generation Tiger Lake parts dropped TSX altogether.

With its latest parts launching with TSX missing in hardware, and the feature being turned off via microcode update in earlier parts, one thing seems clear: Intel is officially done with TSX in its current form.

News URL

https://go.theregister.com/feed/www.theregister.com/2021/06/29/intel_tsx_disabled/