1 files changed, 25 insertions, 14 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 758938c94..08fe77d2a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1144,6 +1144,7 @@ static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 #define NO_SPECTRE_V2		BIT(8)
 #define NO_MMIO			BIT(9)
 #define NO_EIBRS_PBRSB		BIT(10)
+#define NO_BHI			BIT(11)
 
 #define VULNWL(vendor, family, model, whitelist)	\
 	X86_MATCH_VENDOR_FAM_MODEL(vendor, family, model, whitelist)
@@ -1206,18 +1207,18 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
 	VULNWL_INTEL(ATOM_TREMONT_D,		NO_ITLB_MULTIHIT | NO_EIBRS_PBRSB),
 
 	/* AMD Family 0xf - 0x12 */
-	VULNWL_AMD(0x0f,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO),
-	VULNWL_AMD(0x10,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO),
-	VULNWL_AMD(0x11,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO),
-	VULNWL_AMD(0x12,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO),
+	VULNWL_AMD(0x0f,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO | NO_BHI),
+	VULNWL_AMD(0x10,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO | NO_BHI),
+	VULNWL_AMD(0x11,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO | NO_BHI),
+	VULNWL_AMD(0x12,	NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO | NO_BHI),
 
 	/* FAMILY_ANY must be last, otherwise 0x0f - 0x12 matches won't work */
-	VULNWL_AMD(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO),
-	VULNWL_HYGON(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO),
+	VULNWL_AMD(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO | NO_EIBRS_PBRSB | NO_BHI),
+	VULNWL_HYGON(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT | NO_MMIO | NO_EIBRS_PBRSB | NO_BHI),
 
 	/* Zhaoxin Family 7 */
-	VULNWL(CENTAUR,	7, X86_MODEL_ANY,	NO_SPECTRE_V2 | NO_SWAPGS | NO_MMIO),
-	VULNWL(ZHAOXIN,	7, X86_MODEL_ANY,	NO_SPECTRE_V2 | NO_SWAPGS | NO_MMIO),
+	VULNWL(CENTAUR,	7, X86_MODEL_ANY,	NO_SPECTRE_V2 | NO_SWAPGS | NO_MMIO | NO_BHI),
+	VULNWL(ZHAOXIN,	7, X86_MODEL_ANY,	NO_SPECTRE_V2 | NO_SWAPGS | NO_MMIO | NO_BHI),
 	{}
 };
 
@@ -1362,8 +1363,16 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 	   !cpu_has(c, X86_FEATURE_AMD_SSB_NO))
 		setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
 
-	if (ia32_cap & ARCH_CAP_IBRS_ALL)
+	/*
+	 * AMD's AutoIBRS is equivalent to Intel's eIBRS - use the Intel feature
+	 * flag and protect from vendor-specific bugs via the whitelist.
+	 */
+	if ((ia32_cap & ARCH_CAP_IBRS_ALL) || cpu_has(c, X86_FEATURE_AUTOIBRS)) {
 		setup_force_cpu_cap(X86_FEATURE_IBRS_ENHANCED);
+		if (!cpu_matches(cpu_vuln_whitelist, NO_EIBRS_PBRSB) &&
+		    !(ia32_cap & ARCH_CAP_PBRSB_NO))
+			setup_force_cpu_bug(X86_BUG_EIBRS_PBRSB);
+	}
 
 	if (!cpu_matches(cpu_vuln_whitelist, NO_MDS) &&
 	    !(ia32_cap & ARCH_CAP_MDS_NO)) {
@@ -1425,11 +1434,6 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 			setup_force_cpu_bug(X86_BUG_RETBLEED);
 	}
 
-	if (cpu_has(c, X86_FEATURE_IBRS_ENHANCED) &&
-	    !cpu_matches(cpu_vuln_whitelist, NO_EIBRS_PBRSB) &&
-	    !(ia32_cap & ARCH_CAP_PBRSB_NO))
-		setup_force_cpu_bug(X86_BUG_EIBRS_PBRSB);
-
 	if (cpu_matches(cpu_vuln_blacklist, SMT_RSB))
 		setup_force_cpu_bug(X86_BUG_SMT_RSB);
 
@@ -1451,6 +1455,13 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 	if (vulnerable_to_rfds(ia32_cap))
 		setup_force_cpu_bug(X86_BUG_RFDS);
 
+	/* When virtualized, eIBRS could be hidden, assume vulnerable */
+	if (!(ia32_cap & ARCH_CAP_BHI_NO) &&
+	    !cpu_matches(cpu_vuln_whitelist, NO_BHI) &&
+	    (boot_cpu_has(X86_FEATURE_IBRS_ENHANCED) ||
+	     boot_cpu_has(X86_FEATURE_HYPERVISOR)))
+		setup_force_cpu_bug(X86_BUG_BHI);
+
 	if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN))
 		return;