From: Michael Tremer <michael.tremer@ipfire.org>
Date: Tue, 11 Jun 2019 17:07:23 +0000 (+0000)
Subject: smt: Only disable SMT when the kernel thinks it is vulnerable
X-Git-Tag: v2.23-core133~7
X-Git-Url: http://git.ipfire.org/?p=ipfire-2.x.git;a=commitdiff_plain;h=894eaf5184dda4f851b01d2ed6806d0b0609b321

smt: Only disable SMT when the kernel thinks it is vulnerable

On virtual machines, it does not make sense to disable SMT for the
virtual cores. This has to be done by the hypervisor.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/initscripts/system/smt b/src/initscripts/system/smt
index f85f567fa8..f83776c1a8 100644
--- a/src/initscripts/system/smt
+++ b/src/initscripts/system/smt
@@ -23,7 +23,7 @@ case "${1}" in
 		# Disable SMT when the processor is vulnerable to Foreshadow or Fallout/ZombieLoad/RIDL
 		for vuln in l1tf mds; do
 			if [ -r "/sys/devices/system/cpu/vulnerabilities/${vuln}" ] && \
-					[ "$(</sys/devices/system/cpu/vulnerabilities/${vuln})" != "Not affected" ]; then
+					[[ "$(</sys/devices/system/cpu/vulnerabilities/${vuln})" =~ "SMT vulnerable" ]]; then
 				# Disable SMT
 				boot_mesg "Disabling Simultaneous Multi-Threading (SMT)..."
 				echo "forceoff" > /sys/devices/system/cpu/smt/control