Again, performance gains leak sensitive data and the solution is to disable some features (and loose performance as well). Seems that Intel chose between performance x security, and security lost.
> Intel DDIO is enabled by default on all Intel Xeon processor E5 family and Intel Xeon processor E7 v2 family platforms. (from https://www.intel.com/content/www/us/en/io/data-direct-i-o-t...)
Seems that it was used in 2012-2014 processors, so it's an attack on 5-years-old processors. Perhaps the impact isn't that great nowadays, but I couldn't find it the same attack can be made in more recent CPUs.
> Yes, DDIO is enabled transparently by default in all Intel server-grade processors since 2012 (Intel Xeon E5, E7 and SP families).
(You can recognize individual people from keystroke timing now. And I don't think this is patched in openssh.)
It isn't good if a remote non-MITM attacker can see the exact timing and cache associativity of remote writes. It doesn't seem from the article that they can monitor timing of other data, but then they also say the CPU does not reserve specific parts of cache for DDIO, leaving open the possibility of recovering information about local process memory/cache operations, the obvious candidate of interest being RSA calcs. I would not be surprised to see more attacks come from this.