On 01/10/2018 06:10 AM, Andrea Arcangeli wrote: > Tim and Dave please comment too, Tim you originally wrote that code > that leaves IBRS always on and never toggles it in the kernel entry > point so you must know full well if Arjan is correct that you must > toggle IBRS every time you enter kernel and in turn ibrs_enabled 2 > isn't valid mode.
Hi Andrea, The "writing IBRS=1 acts as a barrier when it is already IBRS=1" behavior is something which I misunderstood in the past. Thanks, Arjan, for clearing it up.
