From 81a3715c7c0b73796a62297ebe55e861a46f7686 Mon Sep 17 00:00:00 2001 From: Raja Grewal Date: Wed, 17 Jul 2024 13:32:08 +1000 Subject: [PATCH] Add info regarding the downsides of disabling SMT --- etc/default/grub.d/40_cpu_mitigations.cfg | 3 +++ 1 file changed, 3 insertions(+) diff --git a/etc/default/grub.d/40_cpu_mitigations.cfg b/etc/default/grub.d/40_cpu_mitigations.cfg index 13d8ffd..e303f9f 100644 --- a/etc/default/grub.d/40_cpu_mitigations.cfg +++ b/etc/default/grub.d/40_cpu_mitigations.cfg @@ -17,9 +17,12 @@ GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mitigations=auto,nosmt" ## Disable SMT as it has been the cause of and amplified numerous CPU exploits. ## The only full mitigation of cross-HT attacks is to disable SMT. +## Disabling will significantly decrease system performance on multi-threaded tasks. +## To enable SMT, remove this line all other occurrences of "nosmt" in this file. ## ## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/core-scheduling.html ## https://forums.whonix.org/t/should-all-kernel-patches-for-cpu-bugs-be-unconditionally-enabled-vs-performance-vs-applicability/7647/17 +## https://github.com/anthraxx/linux-hardened/issues/37#issuecomment-619597365 ## GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX nosmt=force"