Merge branch 'kvm-tsx-ctrl' into HEAD

Conflicts:
	arch/x86/kvm/vmx/vmx.c

35 files changed, 1098 insertions, 207 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d6e1faa28c58..8ef85139553f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1940,6 +1940,51 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS
 
 	  If unsure, say y.
 
+choice
+	prompt "TSX enable mode"
+	depends on CPU_SUP_INTEL
+	default X86_INTEL_TSX_MODE_OFF
+	help
+	  Intel's TSX (Transactional Synchronization Extensions) feature
+	  allows to optimize locking protocols through lock elision which
+	  can lead to a noticeable performance boost.
+
+	  On the other hand it has been shown that TSX can be exploited
+	  to form side channel attacks (e.g. TAA) and chances are there
+	  will be more of those attacks discovered in the future.
+
+	  Therefore TSX is not enabled by default (aka tsx=off). An admin
+	  might override this decision by tsx=on the command line parameter.
+	  Even with TSX enabled, the kernel will attempt to enable the best
+	  possible TAA mitigation setting depending on the microcode available
+	  for the particular machine.
+
+	  This option allows to set the default tsx mode between tsx=on, =off
+	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
+	  details.
+
+	  Say off if not sure, auto if TSX is in use but it should be used on safe
+	  platforms or on if TSX is in use and the security aspect of tsx is not
+	  relevant.
+
+config X86_INTEL_TSX_MODE_OFF
+	bool "off"
+	help
+	  TSX is disabled if possible - equals to tsx=off command line parameter.
+
+config X86_INTEL_TSX_MODE_ON
+	bool "on"
+	help
+	  TSX is always enabled on TSX capable HW - equals the tsx=on command
+	  line parameter.
+
+config X86_INTEL_TSX_MODE_AUTO
+	bool "auto"
+	help
+	  TSX is enabled on TSX capable HW that is believed to be safe against
+	  side channel attacks- equals the tsx=auto command line parameter.
+endchoice
+
 config EFI
 	bool "EFI runtime service support"
 	depends on ACPI
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index d6662fdef300..82bc60c8acb2 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -13,6 +13,7 @@
 #include <asm/e820/types.h>
 #include <asm/setup.h>
 #include <asm/desc.h>
+#include <asm/boot.h>
 
 #include "../string.h"
 #include "eboot.h"
@@ -813,7 +814,8 @@ efi_main(struct efi_config *c, struct boot_params *boot_params)
 		status = efi_relocate_kernel(sys_table, &bzimage_addr,
 					     hdr->init_size, hdr->init_size,
 					     hdr->pref_address,
-					     hdr->kernel_alignment);
+					     hdr->kernel_alignment,
+					     LOAD_PHYSICAL_ADDR);
 		if (status != EFI_SUCCESS) {
 			efi_printk(sys_table, "efi_relocate_kernel() failed!\n");
 			goto fail;
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index 5b35b7ea5d72..26c36357c4c9 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -377,7 +377,8 @@ static inline void perf_ibs_disable_event(struct perf_ibs *perf_ibs,
 					  struct hw_perf_event *hwc, u64 config)
 {
 	config &= ~perf_ibs->cnt_mask;
-	wrmsrl(hwc->config_base, config);
+	if (boot_cpu_data.x86 == 0x10)
+		wrmsrl(hwc->config_base, config);
 	config &= ~perf_ibs->enable_mask;
 	wrmsrl(hwc->config_base, config);
 }
@@ -553,7 +554,8 @@ static struct perf_ibs perf_ibs_op = {
 	},
 	.msr			= MSR_AMD64_IBSOPCTL,
 	.config_mask		= IBS_OP_CONFIG_MASK,
-	.cnt_mask		= IBS_OP_MAX_CNT,
+	.cnt_mask		= IBS_OP_MAX_CNT | IBS_OP_CUR_CNT |
+				  IBS_OP_CUR_CNT_RAND,
 	.enable_mask		= IBS_OP_ENABLE,
 	.valid_mask		= IBS_OP_VAL,
 	.max_period		= IBS_OP_MAX_CNT << 4,
@@ -614,7 +616,7 @@ fail:
 	if (event->attr.sample_type & PERF_SAMPLE_RAW)
 		offset_max = perf_ibs->offset_max;
 	else if (check_rip)
-		offset_max = 2;
+		offset_max = 3;
 	else
 		offset_max = 1;
 	do {
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 74e80ed9c6c4..05e43d0f430b 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -627,7 +627,7 @@ static struct topa *topa_alloc(int cpu, gfp_t gfp)
 	 * link as the 2nd entry in the table
 	 */
 	if (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries)) {
-		TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p);
+		TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p) >> TOPA_SHIFT;
 		TOPA_ENTRY(&tp->topa, 1)->end = 1;
 	}
 
diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 6fc2e06ab4c6..86467f85c383 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -502,10 +502,8 @@ void uncore_pmu_event_start(struct perf_event *event, int flags)
 	local64_set(&event->hw.prev_count, uncore_read_counter(box, event));
 	uncore_enable_event(box, event);
 
-	if (box->n_active == 1) {
-		uncore_enable_box(box);
+	if (box->n_active == 1)
 		uncore_pmu_start_hrtimer(box);
-	}
 }
 
 void uncore_pmu_event_stop(struct perf_event *event, int flags)
@@ -529,10 +527,8 @@ void uncore_pmu_event_stop(struct perf_event *event, int flags)
 		WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
 		hwc->state |= PERF_HES_STOPPED;
 
-		if (box->n_active == 0) {
-			uncore_disable_box(box);
+		if (box->n_active == 0)
 			uncore_pmu_cancel_hrtimer(box);
-		}
 	}
 
 	if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
@@ -778,6 +774,40 @@ static int uncore_pmu_event_init(struct perf_event *event)
 	return ret;
 }
 
+static void uncore_pmu_enable(struct pmu *pmu)
+{
+	struct intel_uncore_pmu *uncore_pmu;
+	struct intel_uncore_box *box;
+
+	uncore_pmu = container_of(pmu, struct intel_uncore_pmu, pmu);
+	if (!uncore_pmu)
+		return;
+
+	box = uncore_pmu_to_box(uncore_pmu, smp_processor_id());
+	if (!box)
+		return;
+
+	if (uncore_pmu->type->ops->enable_box)
+		uncore_pmu->type->ops->enable_box(box);
+}
+
+static void uncore_pmu_disable(struct pmu *pmu)
+{
+	struct intel_uncore_pmu *uncore_pmu;
+	struct intel_uncore_box *box;
+
+	uncore_pmu = container_of(pmu, struct intel_uncore_pmu, pmu);
+	if (!uncore_pmu)
+		return;
+
+	box = uncore_pmu_to_box(uncore_pmu, smp_processor_id());
+	if (!box)
+		return;
+
+	if (uncore_pmu->type->ops->disable_box)
+		uncore_pmu->type->ops->disable_box(box);
+}
+
 static ssize_t uncore_get_attr_cpumask(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
@@ -803,6 +833,8 @@ static int uncore_pmu_register(struct intel_uncore_pmu *pmu)
 		pmu->pmu = (struct pmu) {
 			.attr_groups	= pmu->type->attr_groups,
 			.task_ctx_nr	= perf_invalid_context,
+			.pmu_enable	= uncore_pmu_enable,
+			.pmu_disable	= uncore_pmu_disable,
 			.event_init	= uncore_pmu_event_init,
 			.add		= uncore_pmu_event_add,
 			.del		= uncore_pmu_event_del,
diff --git a/arch/x86/events/intel/uncore.h b/arch/x86/events/intel/uncore.h
index f36f7bebbc1b..bbfdaa720b45 100644
--- a/arch/x86/events/intel/uncore.h
+++ b/arch/x86/events/intel/uncore.h
@@ -441,18 +441,6 @@ static inline int uncore_freerunning_hw_config(struct intel_uncore_box *box,
 	return -EINVAL;
 }
 
-static inline void uncore_disable_box(struct intel_uncore_box *box)
-{
-	if (box->pmu->type->ops->disable_box)
-		box->pmu->type->ops->disable_box(box);
-}
-
-static inline void uncore_enable_box(struct intel_uncore_box *box)
-{
-	if (box->pmu->type->ops->enable_box)
-		box->pmu->type->ops->enable_box(box);
-}
-
 static inline void uncore_disable_event(struct intel_uncore_box *box,
 				struct perf_event *event)
 {
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 0652d3eed9bd..c4fbe379cc0b 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -399,5 +399,7 @@
 #define X86_BUG_MDS			X86_BUG(19) /* CPU is affected by Microarchitectural data sampling */
 #define X86_BUG_MSBDS_ONLY		X86_BUG(20) /* CPU is only affected by the  MSDBS variant of BUG_MDS */
 #define X86_BUG_SWAPGS			X86_BUG(21) /* CPU is affected by speculation through SWAPGS */
+#define X86_BUG_TAA			X86_BUG(22) /* CPU is affected by TSX Async Abort(TAA) */
+#define X86_BUG_ITLB_MULTIHIT		X86_BUG(23) /* CPU may incur MCE during certain page attribute changes */
 
 #endif /* _ASM_X86_CPUFEATURES_H */
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 898ab9eb4dc8..b79cd6aa4075 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -310,9 +310,12 @@ struct kvm_rmap_head {
 struct kvm_mmu_page {
 	struct list_head link;
 	struct hlist_node hash_link;
+	struct list_head lpage_disallowed_link;
+
 	bool unsync;
 	u8 mmu_valid_gen;
 	bool mmio_cached;
+	bool lpage_disallowed; /* Can't be replaced by an equiv large page */
 
 	/*
 	 * The following two entries are used to key the shadow page in the
@@ -877,6 +880,7 @@ struct kvm_arch {
 	 */
 	struct list_head active_mmu_pages;
 	struct list_head zapped_obsolete_pages;
+	struct list_head lpage_disallowed_mmu_pages;
 	struct kvm_page_track_notifier_node mmu_sp_tracker;
 	struct kvm_page_track_notifier_head track_notifier_head;
 
@@ -951,6 +955,7 @@ struct kvm_arch {
 	bool exception_payload_enabled;
 
 	struct kvm_pmu_event_filter *pmu_event_filter;
+	struct task_struct *nx_lpage_recovery_thread;
 };
 
 struct kvm_vm_stat {
@@ -964,6 +969,7 @@ struct kvm_vm_stat {
 	ulong mmu_unsync;
 	ulong remote_tlb_flush;
 	ulong lpages;
+	ulong nx_lpage_splits;
 	ulong max_mmu_page_hash_collisions;
 };
 
@@ -1206,7 +1212,7 @@ struct kvm_x86_ops {
 	int (*set_nested_state)(struct kvm_vcpu *vcpu,
 				struct kvm_nested_state __user *user_kvm_nested_state,
 				struct kvm_nested_state *kvm_state);
-	void (*get_vmcs12_pages)(struct kvm_vcpu *vcpu);
+	bool (*get_vmcs12_pages)(struct kvm_vcpu *vcpu);
 
 	int (*smi_allowed)(struct kvm_vcpu *vcpu);
 	int (*pre_enter_smm)(struct kvm_vcpu *vcpu, char *smstate);
@@ -1368,6 +1374,7 @@ int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,
 
 void kvm_enable_efer_bits(u64);
 bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer);
+int __kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data, bool host_initiated);
 int kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data);
 int kvm_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data);
 int kvm_emulate_rdmsr(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 20ce682a2540..6a3124664289 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -93,6 +93,18 @@
 						  * Microarchitectural Data
 						  * Sampling (MDS) vulnerabilities.
 						  */
+#define ARCH_CAP_PSCHANGE_MC_NO		BIT(6)	 /*
+						  * The processor is not susceptible to a
+						  * machine check error due to modifying the
+						  * code page size along with either the
+						  * physical address or cache type
+						  * without TLB invalidation.
+						  */
+#define ARCH_CAP_TSX_CTRL_MSR		BIT(7)	/* MSR for TSX control is available. */
+#define ARCH_CAP_TAA_NO			BIT(8)	/*
+						 * Not susceptible to
+						 * TSX Async Abort (TAA) vulnerabilities.
+						 */
 
 #define MSR_IA32_FLUSH_CMD		0x0000010b
 #define L1D_FLUSH			BIT(0)	/*
@@ -103,6 +115,10 @@
 #define MSR_IA32_BBL_CR_CTL		0x00000119
 #define MSR_IA32_BBL_CR_CTL3		0x0000011e
 
+#define MSR_IA32_TSX_CTRL		0x00000122
+#define TSX_CTRL_RTM_DISABLE		BIT(0)	/* Disable RTM feature */
+#define TSX_CTRL_CPUID_CLEAR		BIT(1)	/* Disable TSX enumeration */
+
 #define MSR_IA32_SYSENTER_CS		0x00000174
 #define MSR_IA32_SYSENTER_ESP		0x00000175
 #define MSR_IA32_SYSENTER_EIP		0x00000176
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 80bc209c0708..5c24a7b35166 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -314,7 +314,7 @@ DECLARE_STATIC_KEY_FALSE(mds_idle_clear);
 #include <asm/segment.h>
 
 /**
- * mds_clear_cpu_buffers - Mitigation for MDS vulnerability
+ * mds_clear_cpu_buffers - Mitigation for MDS and TAA vulnerability
  *
  * This uses the otherwise unused and obsolete VERW instruction in
  * combination with microcode which triggers a CPU buffer flush when the
@@ -337,7 +337,7 @@ static inline void mds_clear_cpu_buffers(void)
 }
 
 /**
- * mds_user_clear_cpu_buffers - Mitigation for MDS vulnerability
+ * mds_user_clear_cpu_buffers - Mitigation for MDS and TAA vulnerability
  *
  * Clear CPU buffers if the corresponding static key is enabled
  */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 6e0a3b43d027..54f5d54280f6 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -988,4 +988,11 @@ enum mds_mitigations {
 	MDS_MITIGATION_VMWERV,
 };
 
+enum taa_mitigations {
+	TAA_MITIGATION_OFF,
+	TAA_MITIGATION_UCODE_NEEDED,
+	TAA_MITIGATION_VERW,
+	TAA_MITIGATION_TSX_DISABLED,
+};
+
 #endif /* _ASM_X86_PROCESSOR_H */
diff --git a/arch/x86/include/asm/vmware.h b/arch/x86/include/asm/vmware.h
index e00c9e875933..ac9fc51e2b18 100644
--- a/arch/x86/include/asm/vmware.h
+++ b/arch/x86/include/asm/vmware.h
@@ -4,6 +4,7 @@
 
 #include <asm/cpufeatures.h>
 #include <asm/alternative.h>
+#include <linux/stringify.h>
 
 /*
  * The hypercall definitions differ in the low word of the %edx argument
@@ -20,8 +21,8 @@
  */
 
 /* Old port-based version */
-#define VMWARE_HYPERVISOR_PORT    "0x5658"
-#define VMWARE_HYPERVISOR_PORT_HB "0x5659"
+#define VMWARE_HYPERVISOR_PORT    0x5658
+#define VMWARE_HYPERVISOR_PORT_HB 0x5659
 
 /* Current vmcall / vmmcall version */
 #define VMWARE_HYPERVISOR_HB   BIT(0)
@@ -29,7 +30,8 @@
 
 /* The low bandwidth call. The low word of edx is presumed clear. */
 #define VMWARE_HYPERCALL						\
-	ALTERNATIVE_2("movw $" VMWARE_HYPERVISOR_PORT ", %%dx; inl (%%dx)", \
+	ALTERNATIVE_2("movw $" __stringify(VMWARE_HYPERVISOR_PORT) ", %%dx; " \
+		      "inl (%%dx), %%eax",				\
 		      "vmcall", X86_FEATURE_VMCALL,			\
 		      "vmmcall", X86_FEATURE_VMW_VMMCALL)
 
@@ -38,7 +40,8 @@
  * HB and OUT bits set.
  */
 #define VMWARE_HYPERCALL_HB_OUT						\
-	ALTERNATIVE_2("movw $" VMWARE_HYPERVISOR_PORT_HB ", %%dx; rep outsb", \
+	ALTERNATIVE_2("movw $" __stringify(VMWARE_HYPERVISOR_PORT_HB) ", %%dx; " \
+		      "rep outsb",					\
 		      "vmcall", X86_FEATURE_VMCALL,			\
 		      "vmmcall", X86_FEATURE_VMW_VMMCALL)
 
@@ -47,7 +50,8 @@
  * HB bit set.
  */
 #define VMWARE_HYPERCALL_HB_IN						\
-	ALTERNATIVE_2("movw $" VMWARE_HYPERVISOR_PORT_HB ", %%dx; rep insb", \
+	ALTERNATIVE_2("movw $" __stringify(VMWARE_HYPERVISOR_PORT_HB) ", %%dx; " \
+		      "rep insb",					\
 		      "vmcall", X86_FEATURE_VMCALL,			\
 		      "vmmcall", X86_FEATURE_VMW_VMMCALL)
 #endif
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 9e2dd2b296cd..2b0faf86da1b 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1586,9 +1586,6 @@ static void setup_local_APIC(void)
 {
 	int cpu = smp_processor_id();
 	unsigned int value;
-#ifdef CONFIG_X86_32
-	int logical_apicid, ldr_apicid;
-#endif
 
 	if (disable_apic) {
 		disable_ioapic_support();
@@ -1626,16 +1623,21 @@ static void setup_local_APIC(void)
 	apic->init_apic_ldr();
 
 #ifdef CONFIG_X86_32
-	/*
-	 * APIC LDR is initialized.  If logical_apicid mapping was
-	 * initialized during get_smp_config(), make sure it matches the
-	 * actual value.
-	 */
-	logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
-	ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
-	WARN_ON(logical_apicid != BAD_APICID && logical_apicid != ldr_apicid);
-	/* always use the value from LDR */
-	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
+	if (apic->dest_logical) {
+		int logical_apicid, ldr_apicid;
+
+		/*
+		 * APIC LDR is initialized.  If logical_apicid mapping was
+		 * initialized during get_smp_config(), make sure it matches
+		 * the actual value.
+		 */
+		logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
+		ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
+		if (logical_apicid != BAD_APICID)
+			WARN_ON(logical_apicid != ldr_apicid);
+		/* Always use the value from LDR. */
+		early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
+	}
 #endif
 
 	/*
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index d7a1e5a9331c..890f60083eca 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -30,7 +30,7 @@ obj-$(CONFIG_PROC_FS)	+= proc.o
 obj-$(CONFIG_X86_FEATURE_NAMES) += capflags.o powerflags.o
 
 ifdef CONFIG_CPU_SUP_INTEL
-obj-y			+= intel.o intel_pconfig.o
+obj-y			+= intel.o intel_pconfig.o tsx.o
 obj-$(CONFIG_PM)	+= intel_epb.o
 endif
 obj-$(CONFIG_CPU_SUP_AMD)		+= amd.o
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 91c2561b905f..4c7b0fa15a19 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -39,6 +39,7 @@ static void __init spectre_v2_select_mitigation(void);
 static void __init ssb_select_mitigation(void);
 static void __init l1tf_select_mitigation(void);
 static void __init mds_select_mitigation(void);
+static void __init taa_select_mitigation(void);
 
 /* The base value of the SPEC_CTRL MSR that always has to be preserved. */
 u64 x86_spec_ctrl_base;
@@ -105,6 +106,7 @@ void __init check_bugs(void)
 	ssb_select_mitigation();
 	l1tf_select_mitigation();
 	mds_select_mitigation();
+	taa_select_mitigation();
 
 	arch_smt_update();
 
@@ -269,6 +271,100 @@ static int __init mds_cmdline(char *str)
 early_param("mds", mds_cmdline);
 
 #undef pr_fmt
+#define pr_fmt(fmt)	"TAA: " fmt
+
+/* Default mitigation for TAA-affected CPUs */
+static enum taa_mitigations taa_mitigation __ro_after_init = TAA_MITIGATION_VERW;
+static bool taa_nosmt __ro_after_init;
+
+static const char * const taa_strings[] = {
+	[TAA_MITIGATION_OFF]		= "Vulnerable",
+	[TAA_MITIGATION_UCODE_NEEDED]	= "Vulnerable: Clear CPU buffers attempted, no microcode",
+	[TAA_MITIGATION_VERW]		= "Mitigation: Clear CPU buffers",
+	[TAA_MITIGATION_TSX_DISABLED]	= "Mitigation: TSX disabled",
+};
+
+static void __init taa_select_mitigation(void)
+{
+	u64 ia32_cap;
+
+	if (!boot_cpu_has_bug(X86_BUG_TAA)) {
+		taa_mitigation = TAA_MITIGATION_OFF;
+		return;
+	}
+
+	/* TSX previously disabled by tsx=off */
+	if (!boot_cpu_has(X86_FEATURE_RTM)) {
+		taa_mitigation = TAA_MITIGATION_TSX_DISABLED;
+		goto out;
+	}
+
+	if (cpu_mitigations_off()) {
+		taa_mitigation = TAA_MITIGATION_OFF;
+		return;
+	}
+
+	/* TAA mitigation is turned off on the cmdline (tsx_async_abort=off) */
+	if (taa_mitigation == TAA_MITIGATION_OFF)
+		goto out;
+
+	if (boot_cpu_has(X86_FEATURE_MD_CLEAR))
+		taa_mitigation = TAA_MITIGATION_VERW;
+	else
+		taa_mitigation = TAA_MITIGATION_UCODE_NEEDED;
+
+	/*
+	 * VERW doesn't clear the CPU buffers when MD_CLEAR=1 and MDS_NO=1.
+	 * A microcode update fixes this behavior to clear CPU buffers. It also
+	 * adds support for MSR_IA32_TSX_CTRL which is enumerated by the
+	 * ARCH_CAP_TSX_CTRL_MSR bit.
+	 *
+	 * On MDS_NO=1 CPUs if ARCH_CAP_TSX_CTRL_MSR is not set, microcode
+	 * update is required.
+	 */
+	ia32_cap = x86_read_arch_cap_msr();
+	if ( (ia32_cap & ARCH_CAP_MDS_NO) &&
+	    !(ia32_cap & ARCH_CAP_TSX_CTRL_MSR))
+		taa_mitigation = TAA_MITIGATION_UCODE_NEEDED;
+
+	/*
+	 * TSX is enabled, select alternate mitigation for TAA which is
+	 * the same as MDS. Enable MDS static branch to clear CPU buffers.
+	 *
+	 * For guests that can't determine whether the correct microcode is
+	 * present on host, enable the mitigation for UCODE_NEEDED as well.
+	 */
+	static_branch_enable(&mds_user_clear);
+
+	if (taa_nosmt || cpu_mitigations_auto_nosmt())
+		cpu_smt_disable(false);
+
+out:
+	pr_info("%s\n", taa_strings[taa_mitigation]);
+}
+
+static int __init tsx_async_abort_parse_cmdline(char *str)
+{
+	if (!boot_cpu_has_bug(X86_BUG_TAA))
+		return 0;
+
+	if (!str)
+		return -EINVAL;
+
+	if (!strcmp(str, "off")) {
+		taa_mitigation = TAA_MITIGATION_OFF;
+	} else if (!strcmp(str, "full")) {
+		taa_mitigation = TAA_MITIGATION_VERW;
+	} else if (!strcmp(str, "full,nosmt")) {
+		taa_mitigation = TAA_MITIGATION_VERW;
+		taa_nosmt = true;
+	}
+
+	return 0;
+}
+early_param("tsx_async_abort", tsx_async_abort_parse_cmdline);
+
+#undef pr_fmt
 #define pr_fmt(fmt)     "Spectre V1 : " fmt
 
 enum spectre_v1_mitigation {
@@ -786,13 +882,10 @@ static void update_mds_branch_idle(void)
 }
 
 #define MDS_MSG_SMT "MDS CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html for more details.\n"
+#define TAA_MSG_SMT "TAA CPU bug present and SMT on, data leak possible. See https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html for more details.\n"
 
 void cpu_bugs_smt_update(void)
 {
-	/* Enhanced IBRS implies STIBP. No update required. */
-	if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
-		return;
-
 	mutex_lock(&spec_ctrl_mutex);
 
 	switch (spectre_v2_user) {
@@ -819,6 +912,17 @@ void cpu_bugs_smt_update(void)
 		break;
 	}
 
+	switch (taa_mitigation) {
+	case TAA_MITIGATION_VERW:
+	case TAA_MITIGATION_UCODE_NEEDED:
+		if (sched_smt_active())
+			pr_warn_once(TAA_MSG_SMT);
+		break;
+	case TAA_MITIGATION_TSX_DISABLED:
+	case TAA_MITIGATION_OFF:
+		break;
+	}
+
 	mutex_unlock(&spec_ctrl_mutex);
 }
 
@@ -1149,6 +1253,9 @@ void x86_spec_ctrl_setup_ap(void)
 		x86_amd_ssb_disable();
 }
 
+bool itlb_multihit_kvm_mitigation;
+EXPORT_SYMBOL_GPL(itlb_multihit_kvm_mitigation);
+
 #undef pr_fmt
 #define pr_fmt(fmt)	"L1TF: " fmt
 
@@ -1304,11 +1411,24 @@ static ssize_t l1tf_show_state(char *buf)
 		       l1tf_vmx_states[l1tf_vmx_mitigation],
 		       sched_smt_active() ? "vulnerable" : "disabled");
 }
+
+static ssize_t itlb_multihit_show_state(char *buf)
+{
+	if (itlb_multihit_kvm_mitigation)
+		return sprintf(buf, "KVM: Mitigation: Split huge pages\n");
+	else
+		return sprintf(buf, "KVM: Vulnerable\n");
+}
 #else
 static ssize_t l1tf_show_state(char *buf)
 {
 	return sprintf(buf, "%s\n", L1TF_DEFAULT_MSG);
 }
+
+static ssize_t itlb_multihit_show_state(char *buf)
+{
+	return sprintf(buf, "Processor vulnerable\n");
+}
 #endif
 
 static ssize_t mds_show_state(char *buf)
@@ -1328,6 +1448,21 @@ static ssize_t mds_show_state(char *buf)
 		       sched_smt_active() ? "vulnerable" : "disabled");
 }
 
+static ssize_t tsx_async_abort_show_state(char *buf)
+{
+	if ((taa_mitigation == TAA_MITIGATION_TSX_DISABLED) ||
+	    (taa_mitigation == TAA_MITIGATION_OFF))
+		return sprintf(buf, "%s\n", taa_strings[taa_mitigation]);
+
+	if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
+		return sprintf(buf, "%s; SMT Host state unknown\n",
+			       taa_strings[taa_mitigation]);
+	}
+
+	return sprintf(buf, "%s; SMT %s\n", taa_strings[taa_mitigation],
+		       sched_smt_active() ? "vulnerable" : "disabled");
+}
+
 static char *stibp_state(void)
 {
 	if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
@@ -1398,6 +1533,12 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
 	case X86_BUG_MDS:
 		return mds_show_state(buf);
 
+	case X86_BUG_TAA:
+		return tsx_async_abort_show_state(buf);
+
+	case X86_BUG_ITLB_MULTIHIT:
+		return itlb_multihit_show_state(buf);
+
 	default:
 		break;
 	}
@@ -1434,4 +1575,14 @@ ssize_t cpu_show_mds(struct device *dev, struct device_attribute *attr, char *bu
 {
 	return cpu_show_common(dev, attr, buf, X86_BUG_MDS);
 }
+
+ssize_t cpu_show_tsx_async_abort(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return cpu_show_common(dev, attr, buf, X86_BUG_TAA);
+}
+
+ssize_t cpu_show_itlb_multihit(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return cpu_show_common(dev, attr, buf, X86_BUG_ITLB_MULTIHIT);
+}
 #endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9ae7d1bcd4f4..fffe21945374 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1016,13 +1016,14 @@ static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 #endif
 }
 
-#define NO_SPECULATION	BIT(0)
-#define NO_MELTDOWN	BIT(1)
-#define NO_SSB		BIT(2)
-#define NO_L1TF		BIT(3)
-#define NO_MDS		BIT(4)
-#define MSBDS_ONLY	BIT(5)
-#define NO_SWAPGS	BIT(6)
+#define NO_SPECULATION		BIT(0)
+#define NO_MELTDOWN		BIT(1)
+#define NO_SSB			BIT(2)
+#define NO_L1TF			BIT(3)
+#define NO_MDS			BIT(4)
+#define MSBDS_ONLY		BIT(5)
+#define NO_SWAPGS		BIT(6)
+#define NO_ITLB_MULTIHIT	BIT(7)
 
 #define VULNWL(_vendor, _family, _model, _whitelist)	\
 	{ X86_VENDOR_##_vendor, _family, _model, X86_FEATURE_ANY, _whitelist }
@@ -1043,27 +1044,27 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
 	VULNWL(NSC,	5, X86_MODEL_ANY,	NO_SPECULATION),
 
 	/* Intel Family 6 */
-	VULNWL_INTEL(ATOM_SALTWELL,		NO_SPECULATION),
-	VULNWL_INTEL(ATOM_SALTWELL_TABLET,	NO_SPECULATION),
-	VULNWL_INTEL(ATOM_SALTWELL_MID,		NO_SPECULATION),
-	VULNWL_INTEL(ATOM_BONNELL,		NO_SPECULATION),
-	VULNWL_INTEL(ATOM_BONNELL_MID,		NO_SPECULATION),
-
-	VULNWL_INTEL(ATOM_SILVERMONT,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
-	VULNWL_INTEL(ATOM_SILVERMONT_D,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
-	VULNWL_INTEL(ATOM_SILVERMONT_MID,	NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
-	VULNWL_INTEL(ATOM_AIRMONT,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
-	VULNWL_INTEL(XEON_PHI_KNL,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
-	VULNWL_INTEL(XEON_PHI_KNM,		NO_SSB | NO_L1TF | MSBDS_ONLY | NO_SWAPGS),
+	VULNWL_INTEL(ATOM_SALTWELL,		NO_SPECULATION | NO_ITLB_MULTIHIT),
+	VULNWL_INTEL(ATOM_SALTWELL_TABLET,	NO_SPECULATION | NO_ITLB_MULTIHIT),
+	VULNWL_INTEL(ATOM_SALTWELL_MID,		NO_SPECULATION | NO_ITLB_MULTIHIT),
+	VULNWL_INTEL(ATOM_BONNELL,