Merge tag 'x86-pti-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 pti updates from Thomas Gleixner:
 "The performance deterioration departement provides a few non-scary
  fixes and improvements:

   - Update the cached HLE state when the TSX state is changed via the
     new control register. This ensures feature bit consistency.

   - Exclude the new Zhaoxin CPUs from Spectre V2 and SWAPGS
     vulnerabilities"

* tag 'x86-pti-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/speculation/swapgs: Exclude Zhaoxin CPUs from SWAPGS vulnerability
  x86/speculation/spectre_v2: Exclude Zhaoxin CPUs from SPECTRE_V2
  x86/cpu: Update cached HLE state on write to TSX_CTRL_CPUID_CLEAR

Author: torvalds

arch/x86/kernel/cpu/common.c

@@ -1023,6 +1023,7 @@ static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 #define MSBDS_ONLY		BIT(5)
 #define NO_SWAPGS		BIT(6)
 #define NO_ITLB_MULTIHIT	BIT(7)
+#define NO_SPECTRE_V2		BIT(8)
 
 #define VULNWL(_vendor, _family, _model, _whitelist)	\
 	{ X86_VENDOR_##_vendor, _family, _model, X86_FEATURE_ANY, _whitelist }
@@ -1084,6 +1085,10 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
 	/* 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),
 	VULNWL_HYGON(X86_FAMILY_ANY,	NO_MELTDOWN | NO_L1TF | NO_MDS | NO_SWAPGS | NO_ITLB_MULTIHIT),
+
+	/* Zhaoxin Family 7 */
+	VULNWL(CENTAUR,	7, X86_MODEL_ANY,	NO_SPECTRE_V2 | NO_SWAPGS),
+	VULNWL(ZHAOXIN,	7, X86_MODEL_ANY,	NO_SPECTRE_V2 | NO_SWAPGS),
 	{}
 };
 
@@ -1116,7 +1121,9 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 		return;
 
 	setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
-	setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+
+	if (!cpu_matches(NO_SPECTRE_V2))
+		setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
 
 	if (!cpu_matches(NO_SSB) && !(ia32_cap & ARCH_CAP_SSB_NO) &&
 	   !cpu_has(c, X86_FEATURE_AMD_SSB_NO))

arch/x86/kernel/cpu/tsx.c

@@ -115,11 +115,12 @@ void __init tsx_init(void)
 		tsx_disable();
 
 		/*
-		 * tsx_disable() will change the state of the
-		 * RTM CPUID bit.  Clear it here since it is now
-		 * expected to be not set.
+		 * tsx_disable() will change the state of the RTM and HLE CPUID
+		 * bits. Clear them here since they are now expected to be not
+		 * set.
 		 */
 		setup_clear_cpu_cap(X86_FEATURE_RTM);
+		setup_clear_cpu_cap(X86_FEATURE_HLE);
 	} else if (tsx_ctrl_state == TSX_CTRL_ENABLE) {
 
 		/*
@@ -131,10 +132,10 @@ void __init tsx_init(void)
 		tsx_enable();
 
 		/*
-		 * tsx_enable() will change the state of the
-		 * RTM CPUID bit.  Force it here since it is now
-		 * expected to be set.
+		 * tsx_enable() will change the state of the RTM and HLE CPUID
+		 * bits. Force them here since they are now expected to be set.
 		 */
 		setup_force_cpu_cap(X86_FEATURE_RTM);
+		setup_force_cpu_cap(X86_FEATURE_HLE);
 	}
 }