x86/bugs: Add attack vector controls for TAA

Use attack vector controls to determine if TAA mitigation is required.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250707183316.1349127-7-david.kaplan@amd.com

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 31e0cf87d71e40349c3e4d8678c5ce6b591f8aef..438c482d4bb0992f7e98059124efb8a4b0bfea08 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -538,12 +538,13 @@ static void __init taa_select_mitigation(void)
                return;
        }
 
-       if (cpu_mitigations_off())
-               taa_mitigation = TAA_MITIGATION_OFF;
-
        /* Microcode will be checked in taa_update_mitigation(). */
-       if (taa_mitigation == TAA_MITIGATION_AUTO)
-               taa_mitigation = TAA_MITIGATION_VERW;
+       if (taa_mitigation == TAA_MITIGATION_AUTO) {
+               if (should_mitigate_vuln(X86_BUG_TAA))
+                       taa_mitigation = TAA_MITIGATION_VERW;
+               else
+                       taa_mitigation = TAA_MITIGATION_OFF;
+       }
 
        if (taa_mitigation != TAA_MITIGATION_OFF)
                verw_clear_cpu_buf_mitigation_selected = true;
@@ -551,7 +552,7 @@ static void __init taa_select_mitigation(void)
 
 static void __init taa_update_mitigation(void)
 {
-       if (!taa_vulnerable() || cpu_mitigations_off())
+       if (!taa_vulnerable())
                return;
 
        if (verw_clear_cpu_buf_mitigation_selected)
@@ -592,7 +593,7 @@ static void __init taa_apply_mitigation(void)
                 */
                setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF);
 
-               if (taa_nosmt || cpu_mitigations_auto_nosmt())
+               if (taa_nosmt || smt_mitigations == SMT_MITIGATIONS_ON)
                        cpu_smt_disable(false);
        }
 }