Re: [RFC PATCH 06/16] x86/split_lock: Save #AC setting for split lock in firmware in boot time and restore the setting in reboot

From: Peter Zijlstra
Date: Thu Jun 21 2018 - 15:58:36 EST


On Sun, May 27, 2018 at 08:45:55AM -0700, Fenghua Yu wrote:
> Firmware may contain split locked instructions.

I think that's the wrong attitude. You should mandate in your BIOS
development guide that Firmware _MUST_NOT_ contain unaligned LOCK
prefixed instructions.