Hyper-Threading erratum rears its head in Skylake and Kaby Lake
by from Techreport on (#2TZ3S)
CPUs can ship with bugs just as software can, and members of the Debian Linux community have uncovered what they claim is a serious one in Intel Skylake and Kaby Lake processors, including Skylake-X CPUs. In a message on the project's mailing list yesterday that was noticed by the eagle-eyed folks at HotHardware, the project says affected CPUs "could, in some situations, dangerously misbehave when hyper-threading is enabled." The message further recommends that users "disable hyper-threading immediately in BIOS/UEFI to work around the problem."
The project member claims the erratum in question is called "Short Loops Which Use AH/BH/CH/DH Registers May Cause Unpredictable System Behavior" ...