x86/CPU/AMD: Prevent improper isolation of shared resources in Zen2's op cache

commit c21b90f776 upstream.

Make sure resources are not improperly shared in the op cache and
cause instruction corruption this way.

Signed-off-by: Prathyushi Nangia <prathyushi.nangia@amd.com>
Co-developed-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/include/asm/msr-index.h

@@ -767,9 +767,10 @@
 #define MSR_AMD64_LBR_SELECT			0xc000010e
 
 /* Zen4 */
-#define MSR_ZEN4_BP_CFG                 0xc001102e
+#define MSR_ZEN4_BP_CFG			0xc001102e
 #define MSR_ZEN4_BP_CFG_BP_SPEC_REDUCE_BIT 4
 #define MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT 5
+#define MSR_ZEN2_BP_CFG_BUG_FIX_BIT	33
 
 /* Fam 19h MSRs */
 #define MSR_F19H_UMC_PERF_CTL           0xc0010800

arch/x86/kernel/cpu/amd.c

@@ -994,6 +994,9 @@ static void init_amd_zen2(struct cpuinfo_x86 *c)
 
 	/* Correct misconfigured CPUID on some clients. */
 	clear_cpu_cap(c, X86_FEATURE_INVLPGB);
+
+	if (!cpu_has(c, X86_FEATURE_HYPERVISOR))
+		msr_set_bit(MSR_ZEN4_BP_CFG, MSR_ZEN2_BP_CFG_BUG_FIX_BIT);
 }
 
 static void init_amd_zen3(struct cpuinfo_x86 *c)

tools/arch/x86/include/asm/msr-index.h

@@ -761,9 +761,10 @@
 #define MSR_AMD64_LBR_SELECT			0xc000010e
 
 /* Zen4 */
-#define MSR_ZEN4_BP_CFG                 0xc001102e
+#define MSR_ZEN4_BP_CFG			0xc001102e
 #define MSR_ZEN4_BP_CFG_BP_SPEC_REDUCE_BIT 4
 #define MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT 5
+#define MSR_ZEN2_BP_CFG_BUG_FIX_BIT	33
 
 /* Fam 19h MSRs */
 #define MSR_F19H_UMC_PERF_CTL           0xc0010800