CVS commit: src/sys/arch/x86/x86

["Maxime Villard" <maxv%netbsd.org@localhost>]

Module Name:    src
Committed By:   maxv
Date:           Wed Mar 14 17:40:41 UTC 2018

Modified Files:
        src/sys/arch/x86/x86: cpu.c x86_machdep.c

Log Message:
Spectre V2 mitigation for certain families of AMD CPUs.

A new sysctl is added, machdep.spectreV2.mitigated, that controls whether
Spectre V2 is mitigated. For now it defaults to "false".

The code is written in such a way that there can be several methods. For
now only one method is supported, on AMD Families 10h, 12h and 16h, where
an MSR is available to disable branch prediction entirely.

Compile-tested on Intel, AMD will be tested soon.


To generate a diff of this commit:
cvs rdiff -u -r1.150 -r1.151 src/sys/arch/x86/x86/cpu.c
cvs rdiff -u -r1.108 -r1.109 src/sys/arch/x86/x86/x86_machdep.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.