[SRU][J][PATCH v2 05/20] x86/CPU/AMD: Move the Zen3 BTC_NO detection to the Zen3 init function

[Juerg Haefliger]

From: "Borislav Petkov (AMD)" <bp at alien8.de>

No functional changes.

Signed-off-by: Borislav Petkov (AMD) <bp at alien8.de>
Reviewed-by: Nikolay Borisov <nik.borisov at suse.com>
Link: http://lore.kernel.org/r/20231120104152.13740-4-bp@alien8.de
(cherry picked from commit affc66cb96f865b3763a8e18add52e133d864f04)
CVE-2024-53114
Signed-off-by: Juerg Haefliger <juerg.haefliger at canonical.com>
---
 arch/x86/kernel/cpu/amd.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 000f7643a2b6..bc864477e27a 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1095,14 +1095,6 @@ static void init_amd_zn(struct cpuinfo_x86 *c)
 		/* Erratum 1076: CPB feature bit not being set in CPUID. */
 		if (!cpu_has(c, X86_FEATURE_CPB))
 			set_cpu_cap(c, X86_FEATURE_CPB);
-
-		/*
-		 * Zen3 (Fam19 model < 0x10) parts are not susceptible to
-		 * Branch Type Confusion, but predate the allocation of the
-		 * BTC_NO bit.
-		 */
-		if (c->x86 == 0x19 && !cpu_has(c, X86_FEATURE_BTC_NO))
-			set_cpu_cap(c, X86_FEATURE_BTC_NO);
 	}
 }
 
@@ -1159,6 +1151,15 @@ static void init_amd_zen2(struct cpuinfo_x86 *c)
 
 static void init_amd_zen3(struct cpuinfo_x86 *c)
 {
+	if (!cpu_has(c, X86_FEATURE_HYPERVISOR)) {
+		/*
+		 * Zen3 (Fam19 model < 0x10) parts are not susceptible to
+		 * Branch Type Confusion, but predate the allocation of the
+		 * BTC_NO bit.
+		 */
+		if (!cpu_has(c, X86_FEATURE_BTC_NO))
+			set_cpu_cap(c, X86_FEATURE_BTC_NO);
+	}
 }
 
 static void init_amd_zen4(struct cpuinfo_x86 *c)
-- 
2.48.1