Re: [PATCH] x86: enable Data Operand Independent Timing Mode

Dave Hansen
2026-03-18T16:23:42Z

On 3/18/26 09:15, Eric Biggers wrote:
> Doesn't DOITM still need to be enabled by default for now, given that
> data-dependent timing is a backwards compatibility break and code hasn't
> been updated to account for it yet?

Please read:

https://lore.kernel.org/all/851920c5-31c9-ddd9-3e2d-57d379aa0671@intel.com/

Especially:

> The execution latency of the DOIT instructions[1] does not depend on the
> value of data operands on all currently-supported Intel processors.

I believe that's a long winded way of saying there's no "backwards
compatibility break".