From 73f1e233327cc0edec83eac322b7f03bcb7fba22 Mon Sep 17 00:00:00 2001 From: Raja Grewal Date: Tue, 19 Jul 2022 02:29:46 +1000 Subject: [PATCH] shuffle and rewording --- etc/default/grub.d/40_cpu_mitigations.cfg | 39 ++++++++++++----------- 1 file changed, 20 insertions(+), 19 deletions(-) diff --git a/etc/default/grub.d/40_cpu_mitigations.cfg b/etc/default/grub.d/40_cpu_mitigations.cfg index 7d6eb65..1977eeb 100644 --- a/etc/default/grub.d/40_cpu_mitigations.cfg +++ b/etc/default/grub.d/40_cpu_mitigations.cfg @@ -1,11 +1,17 @@ ## Copyright (C) 2019 - 2022 ENCRYPTED SUPPORT LP ## See the file COPYING for copying conditions. -## Enables all mitigations for CPU vulnerabilities. +## Enables all known mitigations for CPU vulnerabilities. ## +## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/index.html ## https://forums.whonix.org/t/should-all-kernel-patches-for-cpu-bugs-be-unconditionally-enabled-vs-performance-vs-applicability/7647 -## Enable all mitigations for Spectre Variant 2. +## Force disable SMT as it has caused numerous CPU vulnerabilities. +## +## https://forums.whonix.org/t/should-all-kernel-patches-for-cpu-bugs-be-unconditionally-enabled-vs-performance-vs-applicability/7647/17 +GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX nosmt=force" + +## Enable mitigations for Spectre variant 2 (indirect branch speculation). ## ## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/spectre.html GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_v2=on" @@ -13,30 +19,25 @@ GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spectre_v2=on" ## Disable Speculative Store Bypass. GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX spec_store_bypass_disable=on" -## Disable TSX, enable all mitigations for the TSX Async Abort -## vulnerability and disable SMT. -## -## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html -GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX tsx=off tsx_async_abort=full,nosmt" - -## Enable all mitigations for the MDS vulnerability and disable -## SMT. -## -## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html -GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mds=full,nosmt" - -## Enable all mitigations for the L1TF vulnerability and disable SMT +## Enable mitigations for the L1TF vulnerability through disabling SMT ## and L1D flush runtime control. ## ## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX l1tf=full,force" -## Force disable SMT as it has caused numerous CPU vulnerabilities. +## Enable mitigations for the MDS vulnerability through clearing buffer cache +## and disabling SMT. ## -## https://forums.whonix.org/t/should-all-kernel-patches-for-cpu-bugs-be-unconditionally-enabled-vs-performance-vs-applicability/7647/17 -GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX nosmt=force" +## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html +GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mds=full,nosmt" + +## Patches the TAA vulnerability by disabling TSX and enables mitigations using +## TSX Async Abort along with disabling SMT. +## +## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html +GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX tsx=off tsx_async_abort=full,nosmt" ## Mark all huge pages in the EPT as non-executable to mitigate iTLB multihit. ## -## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/multihit.html#mitigation-control-on-the-kernel-command-line-and-kvm-module-parameter +## https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/multihit.html GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX kvm.nx_huge_pages=force"