linux-kernel - [tip: x86/cpu] x86/CPU/AMD: Call the spectral chicken in the Zen2 init function

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Date:   Wed, 29 Nov 2023 11:22:30 -0000
From:   "tip-bot2 for Borislav Petkov (AMD)" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     "Borislav Petkov (AMD)" <bp@...en8.de>,
        Nikolay Borisov <nik.borisov@...e.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/cpu] x86/CPU/AMD: Call the spectral chicken in the Zen2
 init function

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID:     cfbf4f992bfce1fa9f2f347a79cbbea0368e7971
Gitweb:        https://git.kernel.org/tip/cfbf4f992bfce1fa9f2f347a79cbbea0368e7971
Author:        Borislav Petkov (AMD) <bp@...en8.de>
AuthorDate:    Wed, 01 Nov 2023 11:20:01 +01:00
Committer:     Borislav Petkov (AMD) <bp@...en8.de>
CommitterDate: Wed, 29 Nov 2023 12:12:20 +01:00

x86/CPU/AMD: Call the spectral chicken in the Zen2 init function

No functional change.

Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Reviewed-by: Nikolay Borisov <nik.borisov@...e.com>
Link: http://lore.kernel.org/r/20231120104152.13740-6-bp@alien8.de
---
 arch/x86/kernel/cpu/amd.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index ebe6be8..82747b6 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1007,10 +1007,8 @@ void init_spectral_chicken(struct cpuinfo_x86 *c)
 	 *
 	 * This suppresses speculation from the middle of a basic block, i.e. it
 	 * suppresses non-branch predictions.
-	 *
-	 * We use STIBP as a heuristic to filter out Zen2 from the rest of F17H
 	 */
-	if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && cpu_has(c, X86_FEATURE_AMD_STIBP)) {
+	if (!cpu_has(c, X86_FEATURE_HYPERVISOR)) {
 		if (!rdmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, &value)) {
 			value |= MSR_ZEN2_SPECTRAL_CHICKEN_BIT;
 			wrmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, value);
@@ -1081,6 +1079,7 @@ static void zenbleed_check(struct cpuinfo_x86 *c)
 
 static void init_amd_zen2(struct cpuinfo_x86 *c)
 {
+	init_spectral_chicken(c);
 	fix_erratum_1386(c);
 }
 
@@ -1136,7 +1135,7 @@ static void init_amd(struct cpuinfo_x86 *c)
 	case 0x12: init_amd_ln(c); break;
 	case 0x15: init_amd_bd(c); break;
 	case 0x16: init_amd_jg(c); break;
-	case 0x17: init_spectral_chicken(c);
+	case 0x17:
 		   fallthrough;
 	case 0x19: init_amd_zn(c); break;
 	}