diff options
| author | David Kaplan <david.kaplan@amd.com> | 2025-07-07 13:33:11 -0500 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2025-07-11 17:56:41 +0200 |
| commit | 2f970a526975f4437bdc9a4ba550ecc7e66d861d (patch) | |
| tree | c081fcd3cfc8101531e13fc7ec03b42a733a5f01 | |
| parent | fdf99228e2f4e0486dc629e87fcece42abfe3f9c (diff) | |
x86/bugs: Add attack vector controls for L1TF
Use attack vector controls to determine if L1TF mitigation is required.
Disable SMT if cross-thread protection is desired.
Signed-off-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250707183316.1349127-17-david.kaplan@amd.com
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 94c72f485707..2128623252a4 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2995,17 +2995,23 @@ static void override_cache_bits(struct cpuinfo_x86 *c) static void __init l1tf_select_mitigation(void) { - if (!boot_cpu_has_bug(X86_BUG_L1TF) || cpu_mitigations_off()) { + if (!boot_cpu_has_bug(X86_BUG_L1TF)) { l1tf_mitigation = L1TF_MITIGATION_OFF; return; } - if (l1tf_mitigation == L1TF_MITIGATION_AUTO) { - if (cpu_mitigations_auto_nosmt()) - l1tf_mitigation = L1TF_MITIGATION_FLUSH_NOSMT; - else - l1tf_mitigation = L1TF_MITIGATION_FLUSH; + if (l1tf_mitigation != L1TF_MITIGATION_AUTO) + return; + + if (!should_mitigate_vuln(X86_BUG_L1TF)) { + l1tf_mitigation = L1TF_MITIGATION_OFF; + return; } + + if (smt_mitigations == SMT_MITIGATIONS_ON) + l1tf_mitigation = L1TF_MITIGATION_FLUSH_NOSMT; + else + l1tf_mitigation = L1TF_MITIGATION_FLUSH; } static void __init l1tf_apply_mitigation(void) |