From: David Kaplan <david.kaplan@amd.com>
Date: Mon, 7 Jul 2025 18:33:03 +0000 (-0500)
Subject: x86/bugs: Add attack vector controls for RFDS
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=54b53dca650bb273655a9a9b5a5b5a3fced0bcc1;p=users%2Fjedix%2Flinux-maple.git

x86/bugs: Add attack vector controls for RFDS

Use attack vector controls to determine if RFDS 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/20250707183316.1349127-9-david.kaplan@amd.com
---

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 39ff556f35c11..a557d174a7519 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -748,13 +748,17 @@ static inline bool __init verw_clears_cpu_reg_file(void)
 
 static void __init rfds_select_mitigation(void)
 {
-	if (!boot_cpu_has_bug(X86_BUG_RFDS) || cpu_mitigations_off()) {
+	if (!boot_cpu_has_bug(X86_BUG_RFDS)) {
 		rfds_mitigation = RFDS_MITIGATION_OFF;
 		return;
 	}
 
-	if (rfds_mitigation == RFDS_MITIGATION_AUTO)
-		rfds_mitigation = RFDS_MITIGATION_VERW;
+	if (rfds_mitigation == RFDS_MITIGATION_AUTO) {
+		if (should_mitigate_vuln(X86_BUG_RFDS))
+			rfds_mitigation = RFDS_MITIGATION_VERW;
+		else
+			rfds_mitigation = RFDS_MITIGATION_OFF;
+	}
 
 	if (rfds_mitigation == RFDS_MITIGATION_OFF)
 		return;
@@ -765,7 +769,7 @@ static void __init rfds_select_mitigation(void)
 
 static void __init rfds_update_mitigation(void)
 {
-	if (!boot_cpu_has_bug(X86_BUG_RFDS) || cpu_mitigations_off())
+	if (!boot_cpu_has_bug(X86_BUG_RFDS))
 		return;
 
 	if (verw_clear_cpu_buf_mitigation_selected)