Re:Disable SMT/Hyperthreading in all Intel BIOSes
by Tuna-Fish on Thursday August 23, 2018 @07:34PM
(#17831495)
> However, I personally wouldn't assume that AMDs HT implementation doesn't have similar issues.
It does not. The fundamental difference between AMD and Intel CPUs in all these faults is that AMD does all permissions checks eagerly before returning results from memory, while when speculating, Intel defers them until speculation is resolved.
This does not mean that AMD escaped all of it, because some of the attacks (eg, spectre variant 1) do not cross a protection boundary that permissions checks would catch.
It does not. The fundamental difference between AMD and Intel CPUs in all these faults is that AMD does all permissions checks eagerly before returning results from memory, while when speculating, Intel defers them until speculation is resolved.
This does not mean that AMD escaped all of it, because some of the attacks (eg, spectre variant 1) do not cross a protection boundary that permissions checks would catch.