diff options
| author | Darrick J. Wong <djwong@kernel.org> | 2021-08-06 11:06:38 -0700 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2021-08-11 09:14:21 -0700 |
| commit | 56790d19c782dfa73f20c6f8d6dca565eaf12713 (patch) | |
| tree | efe13815a192650e58543ab10de9039c0ae82e0a | |
| parent | 50006959bcae8115f1dec86141e0312751e980dc (diff) | |
kconfig: allow setting default cpu mitigations
Allow the kernel builder to set the default cpu mitigation level.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
| -rw-r--r-- | kernel/Kconfig.preempt | 28 | ||||
| -rw-r--r-- | kernel/cpu.c | 6 |
2 files changed, 34 insertions, 0 deletions
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index 5876e30c5740..c34b775e844e 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -1,6 +1,34 @@ # SPDX-License-Identifier: GPL-2.0-only choice + prompt "CPU Vulnerability Mitigation Defaults" + default CPU_MITIGATIONS_AUTO + help + Set the level of CPU security vulnerability mitigations that are + applied by default. These can still be overridden by command line + options at boot time. + +config CPU_MITIGATIONS_OFF + bool "No CPU mitigations" + help + Disable all CPU mitigations. This restores performance to pre-2018 + levels on old hardware but leaves your system at risk. + +config CPU_MITIGATIONS_AUTO + bool "Automatic CPU mitigations" + help + Turn on whatever CPU mitigations are necessary for the booted CPUs. + Leave SMT enabled. + +config CPU_MITIGATIONS_AUTO_NOSMT + bool "Automatic CPU mitigations, disable SMT" + help + Turn on whatever CPU mitigations are necessary for the booted CPUs. + Disable SMT unconditionally. + +endchoice + +choice prompt "Preemption Model" default PREEMPT_NONE diff --git a/kernel/cpu.c b/kernel/cpu.c index 804b847912dc..902c734970ea 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -2652,7 +2652,13 @@ enum cpu_mitigations { }; static enum cpu_mitigations cpu_mitigations __ro_after_init = +#ifdef CONFIG_CPU_MITIGATIONS_OFF + CPU_MITIGATIONS_OFF; +#elif defined CONFIG_CPU_MITIGATIONS_AUTO CPU_MITIGATIONS_AUTO; +#elif defined CONFIG_CPU_MITIGATIONS_AUTO_NOSMT + CPU_MITIGATIONS_AUTO_NOSMT; +#endif static int __init mitigations_parse_cmdline(char *arg) { |