Adding upstream version 6.7.7.upstream/6.7.7

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

18 files changed, 387 insertions, 162 deletions

diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index ed90f14814..950c12868d 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -154,4 +154,15 @@ config KVM_PROVE_MMU
 config KVM_EXTERNAL_WRITE_TRACKING
 	bool
 
+config KVM_MAX_NR_VCPUS
+	int "Maximum number of vCPUs per KVM guest"
+	depends on KVM
+	range 1024 4096
+	default 4096 if MAXSMP
+	default 1024
+	help
+	  Set the maximum number of vCPUs per KVM guest. Larger values will increase
+	  the memory footprint of each KVM guest, regardless of how many vCPUs are
+	  created for a given VM.
+
 endif # VIRTUALIZATION
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 773132c3bf..dda6fc4cfa 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -448,7 +448,9 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
 	vcpu->arch.cpuid_nent = nent;
 
 	vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE);
+#ifdef CONFIG_KVM_XEN
 	vcpu->arch.xen.cpuid = kvm_get_hypervisor_cpuid(vcpu, XEN_SIGNATURE);
+#endif
 	kvm_vcpu_after_set_cpuid(vcpu);
 
 	return 0;
@@ -753,11 +755,13 @@ void kvm_set_cpu_caps(void)
 
 	kvm_cpu_cap_mask(CPUID_8000_0021_EAX,
 		F(NO_NESTED_DATA_BP) | F(LFENCE_RDTSC) | 0 /* SmmPgCfgLock */ |
-		F(NULL_SEL_CLR_BASE) | F(AUTOIBRS) | 0 /* PrefetchCtlMsr */
+		F(NULL_SEL_CLR_BASE) | F(AUTOIBRS) | 0 /* PrefetchCtlMsr */ |
+		F(WRMSR_XX_BASE_NS)
 	);
 
-	if (cpu_feature_enabled(X86_FEATURE_SRSO_NO))
-		kvm_cpu_cap_set(X86_FEATURE_SRSO_NO);
+	kvm_cpu_cap_check_and_set(X86_FEATURE_SBPB);
+	kvm_cpu_cap_check_and_set(X86_FEATURE_IBPB_BRTYPE);
+	kvm_cpu_cap_check_and_set(X86_FEATURE_SRSO_NO);
 
 	kvm_cpu_cap_init_kvm_defined(CPUID_8000_0022_EAX,
 		F(PERFMON_V2)
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 284fa47045..0b90532b6e 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -174,7 +174,8 @@ static inline bool guest_has_spec_ctrl_msr(struct kvm_vcpu *vcpu)
 static inline bool guest_has_pred_cmd_msr(struct kvm_vcpu *vcpu)
 {
 	return (guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) ||
-		guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBPB));
+		guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBPB) ||
+		guest_cpuid_has(vcpu, X86_FEATURE_SBPB));
 }
 
 static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c
index ee8c4c3496..eea6ea7f14 100644
--- a/arch/x86/kvm/debugfs.c
+++ b/arch/x86/kvm/debugfs.c
@@ -182,6 +182,7 @@ static int kvm_mmu_rmaps_stat_release(struct inode *inode, struct file *file)
 }
 
 static const struct file_operations mmu_rmaps_stat_fops = {
+	.owner		= THIS_MODULE,
 	.open		= kvm_mmu_rmaps_stat_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 253fb2093d..bb8c86eefa 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -237,6 +237,13 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 	return -(u32)fault & errcode;
 }
 
+bool __kvm_mmu_honors_guest_mtrrs(bool vm_has_noncoherent_dma);
+
+static inline bool kvm_mmu_honors_guest_mtrrs(struct kvm *kvm)
+{
+	return __kvm_mmu_honors_guest_mtrrs(kvm_arch_has_noncoherent_dma(kvm));
+}
+
 void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end);
 
 int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index f7901cb4d2..c57e181bba 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3425,8 +3425,8 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 {
 	struct kvm_mmu_page *sp;
 	int ret = RET_PF_INVALID;
-	u64 spte = 0ull;
-	u64 *sptep = NULL;
+	u64 spte;
+	u64 *sptep;
 	uint retry_count = 0;
 
 	if (!page_fault_can_be_fast(fault))
@@ -3442,6 +3442,14 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 		else
 			sptep = fast_pf_get_last_sptep(vcpu, fault->addr, &spte);
 
+		/*
+		 * It's entirely possible for the mapping to have been zapped
+		 * by a different task, but the root page should always be
+		 * available as the vCPU holds a reference to its root(s).
+		 */
+		if (WARN_ON_ONCE(!sptep))
+			spte = REMOVED_SPTE;
+
 		if (!is_shadow_present_pte(spte))
 			break;
 
@@ -4479,21 +4487,28 @@ out_unlock:
 }
 #endif
 
-int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
+bool __kvm_mmu_honors_guest_mtrrs(bool vm_has_noncoherent_dma)
 {
 	/*
-	 * If the guest's MTRRs may be used to compute the "real" memtype,
-	 * restrict the mapping level to ensure KVM uses a consistent memtype
-	 * across the entire mapping.  If the host MTRRs are ignored by TDP
-	 * (shadow_memtype_mask is non-zero), and the VM has non-coherent DMA
-	 * (DMA doesn't snoop CPU caches), KVM's ABI is to honor the memtype
-	 * from the guest's MTRRs so that guest accesses to memory that is
-	 * DMA'd aren't cached against the guest's wishes.
+	 * If host MTRRs are ignored (shadow_memtype_mask is non-zero), and the
+	 * VM has non-coherent DMA (DMA doesn't snoop CPU caches), KVM's ABI is
+	 * to honor the memtype from the guest's MTRRs so that guest accesses
+	 * to memory that is DMA'd aren't cached against the guest's wishes.
 	 *
 	 * Note, KVM may still ultimately ignore guest MTRRs for certain PFNs,
 	 * e.g. KVM will force UC memtype for host MMIO.
 	 */
-	if (shadow_memtype_mask && kvm_arch_has_noncoherent_dma(vcpu->kvm)) {
+	return vm_has_noncoherent_dma && shadow_memtype_mask;
+}
+
+int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
+{
+	/*
+	 * If the guest's MTRRs may be used to compute the "real" memtype,
+	 * restrict the mapping level to ensure KVM uses a consistent memtype
+	 * across the entire mapping.
+	 */
+	if (kvm_mmu_honors_guest_mtrrs(vcpu->kvm)) {
 		for ( ; fault->max_level > PG_LEVEL_4K; --fault->max_level) {
 			int page_num = KVM_PAGES_PER_HPAGE(fault->max_level);
 			gfn_t base = gfn_round_for_level(fault->gfn,
@@ -6785,11 +6800,7 @@ static unsigned long mmu_shrink_count(struct shrinker *shrink,
 	return percpu_counter_read_positive(&kvm_total_used_mmu_pages);
 }
 
-static struct shrinker mmu_shrinker = {
-	.count_objects = mmu_shrink_count,
-	.scan_objects = mmu_shrink_scan,
-	.seeks = DEFAULT_SEEKS * 10,
-};
+static struct shrinker *mmu_shrinker;
 
 static void mmu_destroy_caches(void)
 {
@@ -6922,10 +6933,16 @@ int kvm_mmu_vendor_module_init(void)
 	if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL))
 		goto out;
 
-	ret = register_shrinker(&mmu_shrinker, "x86-mmu");
-	if (ret)
+	mmu_shrinker = shrinker_alloc(0, "x86-mmu");
+	if (!mmu_shrinker)
 		goto out_shrinker;
 
+	mmu_shrinker->count_objects = mmu_shrink_count;
+	mmu_shrinker->scan_objects = mmu_shrink_scan;
+	mmu_shrinker->seeks = DEFAULT_SEEKS * 10;
+
+	shrinker_register(mmu_shrinker);
+
 	return 0;
 
 out_shrinker:
@@ -6947,7 +6964,7 @@ void kvm_mmu_vendor_module_exit(void)
 {
 	mmu_destroy_caches();
 	percpu_counter_destroy(&kvm_total_used_mmu_pages);
-	unregister_shrinker(&mmu_shrinker);
+	shrinker_free(mmu_shrinker);
 }
 
 /*
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index 3eb6e7f47e..a67c28a564 100644
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -320,7 +320,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
 	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
 	gfn_t start, end;
 
-	if (!tdp_enabled || !kvm_arch_has_noncoherent_dma(vcpu->kvm))
+	if (!kvm_mmu_honors_guest_mtrrs(vcpu->kvm))
 		return;
 
 	if (!mtrr_is_enabled(mtrr_state) && msr != MSR_MTRRdefType)
diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c
index b42111a24c..dc3d95fdca 100644
--- a/arch/x86/kvm/smm.c
+++ b/arch/x86/kvm/smm.c
@@ -324,7 +324,6 @@ void enter_smm(struct kvm_vcpu *vcpu)
 
 	cr0 = vcpu->arch.cr0 & ~(X86_CR0_PE | X86_CR0_EM | X86_CR0_TS | X86_CR0_PG);
 	static_call(kvm_x86_set_cr0)(vcpu, cr0);
-	vcpu->arch.cr0 = cr0;
 
 	static_call(kvm_x86_set_cr4)(vcpu, 0);
 
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 4900c07804..6ee925d666 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2972,6 +2972,25 @@ static void sev_es_vcpu_after_set_cpuid(struct vcpu_svm *svm)
 
 		set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, v_tsc_aux, v_tsc_aux);
 	}
+
+	/*
+	 * For SEV-ES, accesses to MSR_IA32_XSS should not be intercepted if
+	 * the host/guest supports its use.
+	 *
+	 * guest_can_use() checks a number of requirements on the host/guest to
+	 * ensure that MSR_IA32_XSS is available, but it might report true even
+	 * if X86_FEATURE_XSAVES isn't configured in the guest to ensure host
+	 * MSR_IA32_XSS is always properly restored. For SEV-ES, it is better
+	 * to further check that the guest CPUID actually supports
+	 * X86_FEATURE_XSAVES so that accesses to MSR_IA32_XSS by misbehaved
+	 * guests will still get intercepted and caught in the normal
+	 * kvm_emulate_rdmsr()/kvm_emulated_wrmsr() paths.
+	 */
+	if (guest_can_use(vcpu, X86_FEATURE_XSAVES) &&
+	    guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))
+		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 1, 1);
+	else
+		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_XSS, 0, 0);
 }
 
 void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 77f1eeefcd..a8bd4e909a 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -103,6 +103,7 @@ static const struct svm_direct_access_msrs {
 	{ .index = MSR_IA32_LASTBRANCHTOIP,		.always = false },
 	{ .index = MSR_IA32_LASTINTFROMIP,		.always = false },
 	{ .index = MSR_IA32_LASTINTTOIP,		.always = false },
+	{ .index = MSR_IA32_XSS,			.always = false },
 	{ .index = MSR_EFER,				.always = false },
 	{ .index = MSR_IA32_CR_PAT,			.always = false },
 	{ .index = MSR_AMD64_SEV_ES_GHCB,		.always = true  },
@@ -199,7 +200,7 @@ module_param_named(npt, npt_enabled, bool, 0444);
 
 /* allow nested virtualization in KVM/SVM */
 static int nested = true;
-module_param(nested, int, S_IRUGO);
+module_param(nested, int, 0444);
 
 /* enable/disable Next RIP Save */
 int nrips = true;
@@ -364,8 +365,6 @@ static void svm_set_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
 		svm->vmcb->control.int_state |= SVM_INTERRUPT_SHADOW_MASK;
 
 }
-static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
-					void *insn, int insn_len);
 
 static int __svm_skip_emulated_instruction(struct kvm_vcpu *vcpu,
 					   bool commit_side_effects)
@@ -386,14 +385,6 @@ static int __svm_skip_emulated_instruction(struct kvm_vcpu *vcpu,
 	}
 
 	if (!svm->next_rip) {
-		/*
-		 * FIXME: Drop this when kvm_emulate_instruction() does the
-		 * right thing and treats "can't emulate" as outright failure
-		 * for EMULTYPE_SKIP.
-		 */
-		if (!svm_can_emulate_instruction(vcpu, EMULTYPE_SKIP, NULL, 0))
-			return 0;
-
 		if (unlikely(!commit_side_effects))
 			old_rflags = svm->vmcb->save.rflags;
 
@@ -531,8 +522,6 @@ static bool __kvm_is_svm_supported(void)
 	int cpu = smp_processor_id();
 	struct cpuinfo_x86 *c = &cpu_data(cpu);
 
-	u64 vm_cr;
-
 	if (c->x86_vendor != X86_VENDOR_AMD &&
 	    c->x86_vendor != X86_VENDOR_HYGON) {
 		pr_err("CPU %d isn't AMD or Hygon\n", cpu);
@@ -549,12 +538,6 @@ static bool __kvm_is_svm_supported(void)
 		return false;
 	}
 
-	rdmsrl(MSR_VM_CR, vm_cr);
-	if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE)) {
-		pr_err("SVM disabled (by BIOS) in MSR_VM_CR on CPU %d\n", cpu);
-		return false;
-	}
-
 	return true;
 }
 
@@ -2204,12 +2187,6 @@ static int shutdown_interception(struct kvm_vcpu *vcpu)
 	struct kvm_run *kvm_run = vcpu->run;
 	struct vcpu_svm *svm = to_svm(vcpu);
 
-	/*
-	 * The VM save area has already been encrypted so it
-	 * cannot be reinitialized - just terminate.
-	 */
-	if (sev_es_guest(vcpu->kvm))
-		return -EINVAL;
 
 	/*
 	 * VMCB is undefined after a SHUTDOWN intercept.  INIT the vCPU to put
@@ -2218,9 +2195,14 @@ static int shutdown_interception(struct kvm_vcpu *vcpu)
 	 * userspace.  At a platform view, INIT is acceptable behavior as
 	 * there exist bare metal platforms that automatically INIT the CPU
 	 * in response to shutdown.
+	 *
+	 * The VM save area for SEV-ES guests has already been encrypted so it
+	 * cannot be reinitialized, i.e. synthesizing INIT is futile.
 	 */
-	clear_page(svm->vmcb);
-	kvm_vcpu_reset(vcpu, true);
+	if (!sev_es_guest(vcpu->kvm)) {
+		clear_page(svm->vmcb);
+		kvm_vcpu_reset(vcpu, true);
+	}
 
 	kvm_run->exit_reason = KVM_EXIT_SHUTDOWN;
 	return 0;
@@ -4729,15 +4711,15 @@ static void svm_enable_smi_window(struct kvm_vcpu *vcpu)
 }
 #endif
 
-static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
-					void *insn, int insn_len)
+static int svm_check_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
+					 void *insn, int insn_len)
 {
 	bool smep, smap, is_user;
 	u64 error_code;
 
 	/* Emulation is always possible when KVM has access to all guest state. */
 	if (!sev_guest(vcpu->kvm))
-		return true;
+		return X86EMUL_CONTINUE;
 
 	/* #UD and #GP should never be intercepted for SEV guests. */
 	WARN_ON_ONCE(emul_type & (EMULTYPE_TRAP_UD |
@@ -4749,14 +4731,14 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
 	 * to guest register state.
 	 */
 	if (sev_es_guest(vcpu->kvm))
-		return false;
+		return X86EMUL_RETRY_INSTR;
 
 	/*
 	 * Emulation is possible if the instruction is already decoded, e.g.
 	 * when completing I/O after returning from userspace.
 	 */
 	if (emul_type & EMULTYPE_NO_DECODE)
-		return true;
+		return X86EMUL_CONTINUE;
 
 	/*
 	 * Emulation is possible for SEV guests if and only if a prefilled
@@ -4782,9 +4764,11 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
 	 * success (and in practice it will work the vast majority of the time).
 	 */
 	if (unlikely(!insn)) {
-		if (!(emul_type & EMULTYPE_SKIP))
-			kvm_queue_exception(vcpu, UD_VECTOR);
-		return false;
+		if (emul_type & EMULTYPE_SKIP)
+			return X86EMUL_UNHANDLEABLE;
+
+		kvm_queue_exception(vcpu, UD_VECTOR);
+		return X86EMUL_PROPAGATE_FAULT;
 	}
 
 	/*
@@ -4795,7 +4779,7 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
 	 * table used to translate CS:RIP resides in emulated MMIO.
 	 */
 	if (likely(insn_len))
-		return true;
+		return X86EMUL_CONTINUE;
 
 	/*
 	 * Detect and workaround Errata 1096 Fam_17h_00_0Fh.
@@ -4853,6 +4837,7 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
 			kvm_inject_gp(vcpu, 0);
 		else
 			kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
+		return X86EMUL_PROPAGATE_FAULT;
 	}
 
 resume_guest:
@@ -4870,7 +4855,7 @@ resume_guest:
 	 * doesn't explicitly define "ignored", i.e. doing nothing and letting
 	 * the guest spin is technically "ignoring" the access.
 	 */
-	return false;
+	return X86EMUL_RETRY_INSTR;
 }
 
 static bool svm_apic_init_signal_blocked(struct kvm_vcpu *vcpu)
@@ -5030,7 +5015,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.vm_copy_enc_context_from = sev_vm_copy_enc_context_from,
 	.vm_move_enc_context_from = sev_vm_move_enc_context_from,
 
-	.can_emulate_instruction = svm_can_emulate_instruction,
+	.check_emulate_instruction = svm_check_emulate_instruction,
 
 	.apic_init_signal_blocked = svm_apic_init_signal_blocked,
 
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index be67ab7fdd..c409f934c3 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -30,7 +30,7 @@
 #define	IOPM_SIZE PAGE_SIZE * 3
 #define	MSRPM_SIZE PAGE_SIZE * 2
 
-#define MAX_DIRECT_ACCESS_MSRS	46
+#define MAX_DIRECT_ACCESS_MSRS	47
 #define MSRPM_OFFSETS	32
 extern u32 msrpm_offsets[MSRPM_OFFSETS] __read_mostly;
 extern bool npt_enabled;
diff --git a/arch/x86/kvm/svm/svm_ops.h b/arch/x86/kvm/svm/svm_ops.h
index 36c8af87a7..4e725854c6 100644
--- a/arch/x86/kvm/svm/svm_ops.h
+++ b/arch/x86/kvm/svm/svm_ops.h
@@ -8,7 +8,7 @@
 
 #define svm_asm(insn, clobber...)				\
 do {								\
-	asm_volatile_goto("1: " __stringify(insn) "\n\t"	\
+	asm goto("1: " __stringify(insn) "\n\t"	\
 			  _ASM_EXTABLE(1b, %l[fault])		\
 			  ::: clobber : fault);			\
 	return;							\
@@ -18,7 +18,7 @@ fault:								\
 
 #define svm_asm1(insn, op1, clobber...)				\
 do {								\
-	asm_volatile_goto("1: "  __stringify(insn) " %0\n\t"	\
+	asm goto("1: "  __stringify(insn) " %0\n\t"	\
 			  _ASM_EXTABLE(1b, %l[fault])		\
 			  :: op1 : clobber : fault);		\
 	return;							\
@@ -28,7 +28,7 @@ fault:								\
 
 #define svm_asm2(insn, op1, op2, clobber...)				\
 do {									\
-	asm_volatile_goto("1: "  __stringify(insn) " %1, %0\n\t"	\
+	asm goto("1: "  __stringify(insn) " %1, %0\n\t"	\
 			  _ASM_EXTABLE(1b, %l[fault])			\
 			  :: op1, op2 : clobber : fault);		\
 	return;								\
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 90c1f7f07e..1549461fa4 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -71,7 +71,7 @@ static int fixed_pmc_events[] = {
 static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
 {
 	struct kvm_pmc *pmc;
-	u8 old_fixed_ctr_ctrl = pmu->fixed_ctr_ctrl;
+	u64 old_fixed_ctr_ctrl = pmu->fixed_ctr_ctrl;
 	int i;
 
 	pmu->fixed_ctr_ctrl = data;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 9bba535258..94082169bb 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -82,28 +82,28 @@ bool __read_mostly enable_vpid = 1;
 module_param_named(vpid, enable_vpid, bool, 0444);
 
 static bool __read_mostly enable_vnmi = 1;
-module_param_named(vnmi, enable_vnmi, bool, S_IRUGO);
+module_param_named(vnmi, enable_vnmi, bool, 0444);
 
 bool __read_mostly flexpriority_enabled = 1;
-module_param_named(flexpriority, flexpriority_enabled, bool, S_IRUGO);
+module_param_named(flexpriority, flexpriority_enabled, bool, 0444);
 
 bool __read_mostly enable_ept = 1;
-module_param_named(ept, enable_ept, bool, S_IRUGO);
+module_param_named(ept, enable_ept, bool, 0444);
 
 bool __read_mostly enable_unrestricted_guest = 1;
 module_param_named(unrestricted_guest,
-			enable_unrestricted_guest, bool, S_IRUGO);
+			enable_unrestricted_guest, bool, 0444);
 
 bool __read_mostly enable_ept_ad_bits = 1;
-module_param_named(eptad, enable_ept_ad_bits, bool, S_IRUGO);
+module_param_named(eptad, enable_ept_ad_bits, bool, 0444);
 
 static bool __read_mostly emulate_invalid_guest_state = true;
-module_param(emulate_invalid_guest_state, bool, S_IRUGO);
+module_param(emulate_invalid_guest_state, bool, 0444);
 
 static bool __read_mostly fasteoi = 1;
-module_param(fasteoi, bool, S_IRUGO);
+module_param(fasteoi, bool, 0444);
 
-module_param(enable_apicv, bool, S_IRUGO);
+module_param(enable_apicv, bool, 0444);
 
 bool __read_mostly enable_ipiv = true;
 module_param(enable_ipiv, bool, 0444);
@@ -114,10 +114,10 @@ module_param(enable_ipiv, bool, 0444);
  * use VMX instructions.
  */
 static bool __read_mostly nested = 1;
-module_param(nested, bool, S_IRUGO);
+module_param(nested, bool, 0444);
 
 bool __read_mostly enable_pml = 1;
-module_param_named(pml, enable_pml, bool, S_IRUGO);
+module_param_named(pml, enable_pml, bool, 0444);
 
 static bool __read_mostly error_on_inconsistent_vmcs_config = true;
 module_param(error_on_inconsistent_vmcs_config, bool, 0444);
@@ -745,7 +745,7 @@ static int vmx_set_guest_uret_msr(struct vcpu_vmx *vmx,
  */
 static int kvm_cpu_vmxoff(void)
 {
-	asm_volatile_goto("1: vmxoff\n\t"
+	asm goto("1: vmxoff\n\t"
 			  _ASM_EXTABLE(1b, %l[fault])
 			  ::: "cc", "memory" : fault);
 
@@ -1657,8 +1657,8 @@ static int vmx_rtit_ctl_check(struct kvm_vcpu *vcpu, u64 data)
 	return 0;
 }
 
-static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
-					void *insn, int insn_len)
+static int vmx_check_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
+					 void *insn, int insn_len)
 {
 	/*
 	 * Emulation of instructions in SGX enclaves is impossible as RIP does
@@ -1669,9 +1669,9 @@ static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
 	 */
 	if (to_vmx(vcpu)->exit_reason.enclave_mode) {
 		kvm_queue_exception(vcpu, UD_VECTOR);
-		return false;
+		return X86EMUL_PROPAGATE_FAULT;
 	}
-	return true;
+	return X86EMUL_CONTINUE;
 }
 
 static int skip_emulated_instruction(struct kvm_vcpu *vcpu)
@@ -2789,7 +2789,7 @@ static int kvm_cpu_vmxon(u64 vmxon_pointer)
 
 	cr4_set_bits(X86_CR4_VMXE);
 
-	asm_volatile_goto("1: vmxon %[vmxon_pointer]\n\t"
+	asm goto("1: vmxon %[vmxon_pointer]\n\t"
 			  _ASM_EXTABLE(1b, %l[fault])
 			  : : [vmxon_pointer] "m"(vmxon_pointer)
 			  : : fault);
@@ -5792,7 +5792,7 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
 {
 	gpa_t gpa;
 
-	if (!vmx_can_emulate_instruction(vcpu, EMULTYPE_PF, NULL, 0))
+	if (vmx_check_emulate_instruction(vcpu, EMULTYPE_PF, NULL, 0))
 		return 1;
 
 	/*
@@ -7579,8 +7579,6 @@ static int vmx_vm_init(struct kvm *kvm)
 
 static u8 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
 {
-	u8 cache;
-
 	/* We wanted to honor guest CD/MTRR/PAT, but doing so could result in
 	 * memory aliases with conflicting memory types and sometimes MCEs.
 	 * We have to be careful as to what are honored and when.
@@ -7607,11 +7605,10 @@ static u8 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
 
 	if (kvm_read_cr0_bits(vcpu, X86_CR0_CD)) {
 		if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED))
-			cache = MTRR_TYPE_WRBACK;
+			return MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT;
 		else
-			cache = MTRR_TYPE_UNCACHABLE;
-
-		return (cache << VMX_EPT_MT_EPTE_SHIFT) | VMX_EPT_IPAT_BIT;
+			return (MTRR_TYPE_UNCACHABLE << VMX_EPT_MT_EPTE_SHIFT) |
+				VMX_EPT_IPAT_BIT;
 	}
 
 	return kvm_mtrr_get_guest_memory_type(vcpu, gfn) << VMX_EPT_MT_EPTE_SHIFT;
@@ -8341,7 +8338,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.enable_smi_window = vmx_enable_smi_window,
 #endif
 
-	.can_emulate_instruction = vmx_can_emulate_instruction,
+	.check_emulate_instruction = vmx_check_emulate_instruction,
 	.apic_init_signal_blocked = vmx_apic_init_signal_blocked,
 	.migrate_timers = vmx_migrate_timers,
 
diff --git a/arch/x86/kvm/vmx/vmx_ops.h b/arch/x86/kvm/vmx/vmx_ops.h
index 33af7b4c6e..6a0c6e81f7 100644
--- a/arch/x86/kvm/vmx/vmx_ops.h
+++ b/arch/x86/kvm/vmx/vmx_ops.h
@@ -94,7 +94,7 @@ static __always_inline unsigned long __vmcs_readl(unsigned long field)
 
 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
 
-	asm_volatile_goto("1: vmread %[field], %[output]\n\t"
+	asm_goto_output("1: vmread %[field], %[output]\n\t"
 			  "jna %l[do_fail]\n\t"
 
 			  _ASM_EXTABLE(1b, %l[do_exception])
@@ -188,7 +188,7 @@ static __always_inline unsigned long vmcs_readl(unsigned long field)
 
 #define vmx_asm1(insn, op1, error_args...)				\
 do {									\
-	asm_volatile_goto("1: " __stringify(insn) " %0\n\t"		\
+	asm goto("1: " __stringify(insn) " %0\n\t"			\
 			  ".byte 0x2e\n\t" /* branch not taken hint */	\
 			  "jna %l[error]\n\t"				\
 			  _ASM_EXTABLE(1b, %l[fault])			\
@@ -205,7 +205,7 @@ fault:									\
 
 #define vmx_asm2(insn, op1, op2, error_args...)				\
 do {									\
-	asm_volatile_goto("1: "  __stringify(insn) " %1, %0\n\t"	\
+	asm goto("1: "  __stringify(insn) " %1, %0\n\t"			\
 			  ".byte 0x2e\n\t" /* branch not taken hint */	\
 			  "jna %l[error]\n\t"				\
 			  _ASM_EXTABLE(1b, %l[fault])			\
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e179db7c17..468870450b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -145,21 +145,21 @@ EXPORT_STATIC_CALL_GPL(kvm_x86_get_cs_db_l_bits);
 EXPORT_STATIC_CALL_GPL(kvm_x86_cache_reg);
 
 static bool __read_mostly ignore_msrs = 0;
-module_param(ignore_msrs, bool, S_IRUGO | S_IWUSR);
+module_param(ignore_msrs, bool, 0644);
 
 bool __read_mostly report_ignored_msrs = true;
-module_param(report_ignored_msrs, bool, S_IRUGO | S_IWUSR);
+module_param(report_ignored_msrs, bool, 0644);
 EXPORT_SYMBOL_GPL(report_ignored_msrs);
 
 unsigned int min_timer_period_us = 200;
-module_param(min_timer_period_us, uint, S_IRUGO | S_IWUSR);
+module_param(min_timer_period_us, uint, 0644);
 
 static bool __read_mostly kvmclock_periodic_sync = true;
-module_param(kvmclock_periodic_sync, bool, S_IRUGO);
+module_param(kvmclock_periodic_sync, bool, 0444);
 
 /* tsc tolerance in parts per million - default to 1/2 of the NTP threshold */
 static u32 __read_mostly tsc_tolerance_ppm = 250;
-module_param(tsc_tolerance_ppm, uint, S_IRUGO | S_IWUSR);
+module_param(tsc_tolerance_ppm, uint, 0644);
 
 /*
  * lapic timer advance (tscdeadline mode only) in nanoseconds.  '-1' enables
@@ -168,13 +168,13 @@ module_param(tsc_tolerance_ppm, uint, S_IRUGO | S_IWUSR);
  * tuning, i.e. allows privileged userspace to set an exact advancement time.
  */
 static int __read_mostly lapic_timer_advance_ns = -1;
-module_param(lapic_timer_advance_ns, int, S_IRUGO | S_IWUSR);
+module_param(lapic_timer_advance_ns, int, 0644);
 
 static bool __read_mostly vector_hashing = true;
-module_param(vector_hashing, bool, S_IRUGO);
+module_param(vector_hashing, bool, 0444);
 
 bool __read_mostly enable_vmware_backdoor = false;
-module_param(enable_vmware_backdoor, bool, S_IRUGO);
+module_param(enable_vmware_backdoor, bool, 0444);
 EXPORT_SYMBOL_GPL(enable_vmware_backdoor);
 
 /*
@@ -186,7 +186,7 @@ static int __read_mostly force_emulation_prefix;
 module_param(force_emulation_prefix, int, 0644);
 
 int __read_mostly pi_inject_timer = -1;
-module_param(pi_inject_timer, bint, S_IRUGO | S_IWUSR);
+module_param(pi_inject_timer, bint, 0644);
 
 /* Enable/disable PMU virtualization */
 bool __read_mostly enable_pmu = true;
@@ -962,7 +962,7 @@ void kvm_post_set_cr0(struct kvm_vcpu *vcpu, unsigned long old_cr0, unsigned lon
 		kvm_mmu_reset_context(vcpu);
 
 	if (((cr0 ^ old_cr0) & X86_CR0_CD) &&
-	    kvm_arch_has_noncoherent_dma(vcpu->kvm) &&
+	    kvm_mmu_honors_guest_mtrrs(vcpu->kvm) &&
 	    !kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED))
 		kvm_zap_gfn_range(vcpu->kvm, 0, ~0ULL);
 }
@@ -2331,14 +2331,9 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock, int sec_hi_o
 	if (kvm_write_guest(kvm, wall_clock, &version, sizeof(version)))
 		return;
 
-	/*
-	 * The guest calculates current wall clock time by adding
-	 * system time (updated by kvm_guest_time_update below) to the
-	 * wall clock specified here.  We do the reverse here.
-	 */
-	wall_nsec = ktime_get_real_ns() - get_kvmclock_ns(kvm);
+	wall_nsec = kvm_get_wall_clock_epoch(kvm);
 
-	wc.nsec = do_div(wall_nsec, 1000000000);
+	wc.nsec = do_div(wall_nsec, NSEC_PER_SEC);
 	wc.sec = (u32)wall_nsec; /* overflow in 2106 guest time */
 	wc.version = version;
 
@@ -2714,8 +2709,9 @@ static void __kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 offset, u64 tsc,
 	kvm_track_tsc_matching(vcpu);
 }
 
-static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 data)
+static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 *user_value)
 {
+	u64 data = user_value ? *user_value : 0;
 	struct kvm *kvm = vcpu->kvm;
 	u64 offset, ns, elapsed;
 	unsigned long flags;
@@ -2730,25 +2726,37 @@ static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 data)
 	if (vcpu->arch.virtual_tsc_khz) {
 		if (data == 0) {
 			/*
-			 * detection of vcpu initialization -- need to sync
-			 * with other vCPUs. This particularly helps to keep
-			 * kvm_clock stable after CPU hotplug
+			 * Force synchronization when creating a vCPU, or when
+			 * userspace explicitly writes a zero value.
 			 */
 			synchronizing = true;
-		} else {
+		} else if (kvm->arch.user_set_tsc) {
 			u64 tsc_exp = kvm->arch.last_tsc_write +
 						nsec_to_cycles(vcpu, elapsed);
 			u64 tsc_hz = vcpu->arch.virtual_tsc_khz * 1000LL;
 			/*
-			 * Special case: TSC write with a small delta (1 second)
-			 * of virtual cycle time against real time is
-			 * interpreted as an attempt to synchronize the CPU.
+			 * Here lies UAPI baggage: when a user-initiated TSC write has
+			 * a small delta (1 second) of virtual cycle time against the
+			 * previously set vCPU, we assume that they were intended to be
+			 * in sync and the delta was only due to the racy nature of the
+			 * legacy API.
+			 *
+			 * This trick falls down when restoring a guest which genuinely
+			 * has been running for less time than the 1 second of imprecision
+			 * which we allow for in the legacy API. In this case, the first
+			 * value written by userspace (on any vCPU) should not be subject
+			 * to this 'correction' to make it sync up with values that only
+			 * come from the kernel's default vCPU creation. Make the 1-second
+			 * slop hack only trigger if the user_set_tsc flag is already set.
 			 */
 			synchronizing = data < tsc_exp + tsc_hz &&
 					data + tsc_hz > tsc_exp;
 		}
 	}
 
+	if (user_value)
+		kvm->arch.user_set_tsc = true;
+
 	/*
 	 * For a reliable TSC, we can match TSC offsets, and for an unstable
 	 * TSC, we add elapsed time in this computation.  We could let the
@@ -3232,16 +3240,94 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
 
 	if (vcpu->pv_time.active)
 		kvm_setup_guest_pvclock(v, &vcpu->pv_time, 0);
+#ifdef CONFIG_KVM_XEN
 	if (vcpu->xen.vcpu_info_cache.active)
 		kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_info_cache,
 					offsetof(struct compat_vcpu_info, time));
 	if (vcpu->xen.vcpu_time_info_cache.active)
 		kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_time_info_cache, 0);
+#endif
 	kvm_hv_setup_tsc_page(v->kvm, &vcpu->hv_clock);
 	return 0;
 }
 
 /*
+ * The pvclock_wall_clock ABI tells the guest the wall clock time at
+ * which it started (i.e. its epoch, when its kvmclock was zero).
+ *
+ * In fact those clocks are subtly different; wall clock frequency is
+ * adjusted by NTP and has leap seconds, while the kvmclock is a
+ * simple function of the TSC without any such adjustment.
+ *
+ * Perhaps the ABI should have exposed CLOCK_TAI and a ratio between
+ * that and kvmclock, but even that would be subject to change over
+ * time.
+ *
+ * Attempt to calculate the epoch at a given moment using the *same*
+ * TSC reading via kvm_get_walltime_and_clockread() to obtain both
+ * wallclock and kvmclock times, and subtracting one from the other.
+ *
+ * Fall back to using their values at slightly different moments by
+ * calling ktime_get_real_ns() and get_kvmclock_ns() separately.
+ */
+uint64_t kvm_get_wall_clock_epoch(struct kvm *kvm)
+{
+#ifdef CONFIG_X86_64
+	struct pvclock_vcpu_time_info hv_clock;
+	struct kvm_arch *ka = &kvm->arch;
+	unsigned long seq, local_tsc_khz;
+	struct timespec64 ts;
+	uint64_t host_tsc;
+
+	do {
+		seq = read_seqcount_begin(&ka->pvclock_sc);
+
+		local_tsc_khz = 0;
+		if (!ka->use_master_clock)
+			break;
+
+		/*
+		 * The TSC read and the call to get_cpu_tsc_khz() must happen
+		 * on the same CPU.
+		 */
+		get_cpu();
+
+		local_tsc_khz = get_cpu_tsc_khz();
+
+		if (local_tsc_khz &&
+		    !kvm_get_walltime_and_clockread(&ts, &host_tsc))
+			local_tsc_khz = 0; /* Fall back to old method */
+
+		put_cpu();
+
+		/*
+		 * These values must be snapshotted within the seqcount loop.
+		 * After that, it's just mathematics which can happen on any
+		 * CPU at any time.
+		 */
+		hv_clock.tsc_timestamp = ka->master_cycle_now;
+		hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset;
+
+	} while (read_seqcount_retry(&ka->pvclock_sc, seq));
+
+	/*
+	 * If the conditions were right, and obtaining the wallclock+TSC was
+	 * successful, calculate the KVM clock at the corresponding time and
+	 * subtract one from the other to get the guest's epoch in nanoseconds
+	 * since 1970-01-01.
+	 */
+	if (local_tsc_khz) {
+		kvm_get_time_scale(NSEC_PER_SEC, local_tsc_khz * NSEC_PER_USEC,
+				   &hv_clock.tsc_shift,
+				   &hv_clock.tsc_to_system_mul);
+		return ts.tv_nsec + NSEC_PER_SEC * ts.tv_sec -
+			__pvclock_read_cycles(&hv_clock, host_tsc);
+	}
+#endif
+	return ktime_get_real_ns() - get_kvmclock_ns(kvm);
+}
+
+/*
  * kvmclock updates which are isolated to a given vcpu, such as
  * vcpu->cpu migration, should not allow system_timestamp from
  * the rest of the vcpus to remain static. Otherwise ntp frequency
@@ -3290,9 +3376,6 @@ static void kvmclock_sync_fn(struct work_struct *work)
 					   kvmclock_sync_work);
 	struct kvm *kvm = container_of(ka, struct kvm, arch);
 
-	if (!kvmclock_periodic_sync)
-		return;
-
 	schedule_delayed_work(&kvm->arch.kvmclock_update_work, 0);
 	schedule_delayed_work(&kvm->arch.kvmclock_sync_work,
 					KVMCLOCK_SYNC_PERIOD);
@@ -3671,17 +3754,36 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		vcpu->arch.perf_capabilities = data;
 		kvm_pmu_refresh(vcpu);
 		break;
-	case MSR_IA32_PRED_CMD:
-		if (!msr_info->host_initiated && !guest_has_pred_cmd_msr(vcpu))
-			return 1;
+	case MSR_IA32_PRED_CMD: {
+		u64 reserved_bits = ~(PRED_CMD_IBPB | PRED_CMD_SBPB);
+
+		if (!msr_info->host_initiated) {
+			if ((!guest_has_pred_cmd_msr(vcpu)))
+				return 1;
+
+			if (!guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) &&
+			    !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBPB))
+				reserved_bits |= PRED_CMD_IBPB;
+
+			if (!guest_cpuid_has(vcpu, X86_FEATURE_SBPB))
+				reserved_bits |= PRED_CMD_SBPB;
+		}
+
+		if (!boot_cpu_has(X86_FEATURE_IBPB))
+			reserved_bits |= PRED_CMD_IBPB;
 
-		if (!boot_cpu_has(X86_FEATURE_IBPB) || (data & ~PRED_CMD_IBPB))
+		if (!boot_cpu_has(X86_FEATURE_SBPB))
+			reserved_bits |= PRED_CMD_SBPB;
+
+		if (data & reserved_bits)
 			return 1;
+
 		if (!data)
 			break;
 
-		wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);
+		wrmsrl(MSR_IA32_PRED_CMD, data);
 		break;
+	}
 	case MSR_IA32_FLUSH_CMD:
 		if (!msr_info->host_initiated &&
 		    !guest_cpuid_has(vcpu, X86_FEATURE_FLUSH_L1D))
@@ -3701,13 +3803,16 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		data &= ~(u64)0x100;	/* ignore ignne emulation enable */
 		data &= ~(u64)0x8;	/* ignore TLB cache disable */
 
-		/* Handle McStatusWrEn */
-		if (data == BIT_ULL(18)) {
-			vcpu->arch.msr_hwcr = data;
-		} else if (data != 0) {
+		/*
+		 * Allow McStatusWrEn and TscFreqSel. (Linux guests from v3.2
+		 * through at least v6.6 whine if TscFreqSel is clear,
+		 * depending on F/M/S.
+		 */
+		if (data & ~(BIT_ULL(18) | BIT_ULL(24))) {
 			kvm_pr_unimpl_wrmsr(vcpu, msr, data);
 			return 1;
 		}
+		vcpu->arch.msr_hwcr = data;
 		break;
 	case MSR_FAM10H_MMIO_CONF_BASE:
 		if (data != 0) {
@@ -3778,7 +3883,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		break;
 	case MSR_IA32_TSC:
 		if (msr_info->host_initiated) {
-			kvm_synchronize_tsc(vcpu, data);
+			kvm_synchronize_tsc(vcpu, &data);
 		} else {
 			u64 adj = kvm_compute_l1_tsc_offset(vcpu, data) - vcpu->arch.l1_tsc_offset;
 			adjust_tsc_offset_guest(vcpu, adj);
@@ -5300,7 +5405,8 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
 	if (events->flags & KVM_VCPUEVENT_VALID_NMI_PENDING) {
 		vcpu->arch.nmi_pending = 0;
 		atomic_set(&vcpu->arch.nmi_queued, events->nmi.pending);
-		kvm_make_request(KVM_REQ_NMI, vcpu);
+		if (events->nmi.pending)
+			kvm_make_request(KVM_REQ_NMI, vcpu);
 	}
 	static_call(kvm_x86_set_nmi_mask)(vcpu, events->nmi.masked);
 
@@ -5413,8 +5519,8 @@ static void kvm_vcpu_ioctl_x86_get_xsave2(struct kvm_vcpu *vcpu,
 static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
 					 struct kvm_xsave *guest_xsave)
 {
-	return kvm_vcpu_ioctl_x86_get_xsave2(vcpu, (void *)guest_xsave->region,
-					     sizeof(guest_xsave->region));
+	kvm_vcpu_ioctl_x86_get_xsave2(vcpu, (void *)guest_xsave->region,
+				      sizeof(guest_xsave->region));
 }
 
 static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu,
@@ -5549,6 +5655,7 @@ static int kvm_arch_tsc_set_attr(struct kvm_vcpu *vcpu,
 		tsc = kvm_scale_tsc(rdtsc(), vcpu->arch.l1_tsc_scaling_ratio) + offset;
 		ns = get_kvmclock_base_ns();
 
+		kvm->arch.user_set_tsc = true;
 		__kvm_synchronize_tsc(vcpu, offset, tsc, ns, matched);
 		raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
 
@@ -6261,6 +6368,9 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
 	struct kvm_vcpu *vcpu;
 	unsigned long i;
 
+	if (!kvm_x86_ops.cpu_dirty_log_size)
+		return;
+
 	kvm_for_each_vcpu(i, vcpu, kvm)
 		kvm_vcpu_kick(vcpu);
 }
@@ -7487,11 +7597,11 @@ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
 }
 EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);
 
-static int kvm_can_emulate_insn(struct kvm_vcpu *vcpu, int emul_type,
-				void *insn, int insn_len)
+static int kvm_check_emulate_insn(struct kvm_vcpu *vcpu, int emul_type,
+				  void *insn, int insn_len)
 {
-	return static_call(kvm_x86_can_emulate_instruction)(vcpu, emul_type,
-							    insn, insn_len);
+	return static_call(kvm_x86_check_emulate_instruction)(vcpu, emul_type,
+							      insn, insn_len);
 }
 
 int handle_ud(struct kvm_vcpu *vcpu)
@@ -7501,8 +7611,10 @@ int handle_ud(struct kvm_vcpu *vcpu)
 	int emul_type = EMULTYPE_TRAP_UD;
 	char sig[5]; /* ud2; .ascii "kvm" */
 	struct x86_exception e;
+	int r;
 
-	if (unlikely(!kvm_can_emulate_insn(vcpu, emul_type, NULL, 0)))
+	r = kvm_check_emulate_insn(vcpu, emul_type, NULL, 0);
+	if (r != X86EMUL_CONTINUE)
 		return 1;
 
 	if (fep_flags &&
@@ -8884,8 +8996,14 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 	struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;
 	bool writeback = true;
 
-	if (unlikely(!kvm_can_emulate_insn(vcpu, emulation_type, insn, insn_len)))
-		return 1;
+	r = kvm_check_emulate_insn(vcpu, emulation_type, insn, insn_len);
+	if (r != X86EMUL_CONTINUE) {
+		if (r == X86EMUL_RETRY_INSTR || r == X86EMUL_PROPAGATE_FAULT)
+			return 1;
+
+		WARN_ON_ONCE(r != X86EMUL_UNHANDLEABLE);
+		return handle_emulation_failure(vcpu, emulation_type);
+	}
 
 	vcpu->arch.l1tf_flush_l1d = true;
 
@@ -10589,16 +10707,16 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		}
 		if (kvm_check_request(KVM_REQ_STEAL_UPDATE, vcpu))
 			record_steal_time(vcpu);
+		if (kvm_check_request(KVM_REQ_PMU, vcpu))
+			kvm_pmu_handle_event(vcpu);
+		if (kvm_check_request(KVM_REQ_PMI, vcpu))
+			kvm_pmu_deliver_pmi(vcpu);
 #ifdef CONFIG_KVM_SMM
 		if (kvm_check_request(KVM_REQ_SMI, vcpu))
 			process_smi(vcpu);
 #endif
 		if (kvm_check_request(KVM_REQ_NMI, vcpu))
 			process_nmi(vcpu);
-		if (kvm_check_request(KVM_REQ_PMU, vcpu))
-			kvm_pmu_handle_event(vcpu);
-		if (kvm_check_request(KVM_REQ_PMI, vcpu))
-			kvm_pmu_deliver_pmi(vcpu);
 		if (kvm_check_request(KVM_REQ_IOAPIC_EOI_EXIT, vcpu)) {
 			BUG_ON(vcpu->arch.pending_ioapic_eoi > 255);
 			if (test_bit(vcpu->arch.pending_ioapic_eoi,
@@ -11534,7 +11652,6 @@ static int __set_sregs_common(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs,
 
 	*mmu_reset_needed |= kvm_read_cr0(vcpu) != sregs->cr0;
 	static_call(kvm_x86_set_cr0)(vcpu, sregs->cr0);
-	vcpu->arch.cr0 = sregs->cr0;
 
 	*mmu_reset_needed |= kvm_read_cr4(vcpu) != sregs->cr4;
 	static_call(kvm_x86_set_cr4)(vcpu, sregs->cr4);
@@ -11578,8 +11695,10 @@ static int __set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 	if (ret)
 		return ret;
 
-	if (mmu_reset_needed)
+	if (mmu_reset_needed) {
 		kvm_mmu_reset_context(vcpu);
+		kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);
+	}
 
 	max_bits = KVM_NR_INTERRUPTS;
 	pending_vec = find_first_bit(
@@ -11620,8 +11739,10 @@ static int __set_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2)
 		mmu_reset_needed = 1;
 		vcpu->arch.pdptrs_from_userspace = true;
 	}
-	if (mmu_reset_needed)
+	if (mmu_reset_needed) {
 		kvm_mmu_reset_context(vcpu);
+		kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);
+	}
 	return 0;
 }
 
@@ -11972,7 +12093,7 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
 	if (mutex_lock_killable(&vcpu->mutex))
 		return;
 	vcpu_load(vcpu);
-	kvm_synchronize_tsc(vcpu, 0);
+	kvm_synchronize_tsc(vcpu, NULL);
 	vcpu_put(vcpu);
 
 	/* poll control enabled by default */
@@ -12328,7 +12449,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 		goto out_uninit_mmu;
 
 	INIT_HLIST_HEAD(&kvm->arch.mask_notifier_list);
-	INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
 	atomic_set(&kvm->arch.noncoherent_dma_count, 0);
 
 	/* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
@@ -12912,7 +13032,10 @@ bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
 	if (vcpu->arch.guest_state_protected)
 		return true;
 
-	return vcpu->arch.preempted_in_kernel;
+	if (vcpu != kvm_get_running_vcpu())
+		return vcpu->arch.preempted_in_kernel;
+
+	return static_call(kvm_x86_get_cpl)(vcpu) == 0;
 }
 
 unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
@@ -13204,15 +13327,30 @@ bool noinstr kvm_arch_has_assigned_device(struct kvm *kvm)
 }
 EXPORT_SYMBOL_GPL(kvm_arch_has_assigned_device);
 
+static void kvm_noncoherent_dma_assignment_start_or_stop(struct kvm *kvm)
+{
+	/*
+	 * Non-coherent DMA assignment and de-assignment will affect
+	 * whether KVM honors guest MTRRs and cause changes in memtypes
+	 * in TDP.
+	 * So, pass %true unconditionally to indicate non-coherent DMA was,
+	 * or will be involved, and that zapping SPTEs might be necessary.
+	 */
+	if (__kvm_mmu_honors_guest_mtrrs(true))
+		kvm_zap_gfn_range(kvm, gpa_to_gfn(0), gpa_to_gfn(~0ULL));
+}
+
 void kvm_arch_register_noncoherent_dma(struct kvm *kvm)
 {
-	atomic_inc(&kvm->arch.noncoherent_dma_count);
+	if (atomic_inc_return(&kvm->arch.noncoherent_dma_count) == 1)
+		kvm_noncoherent_dma_assignment_start_or_stop(kvm);
 }
 EXPORT_SYMBOL_GPL(kvm_arch_register_noncoherent_dma);
 
 void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm)
 {
-	atomic_dec(&kvm->arch.noncoherent_dma_count);
+	if (!atomic_dec_return(&kvm->arch.noncoherent_dma_count))
+		kvm_noncoherent_dma_assignment_start_or_stop(kvm);
 }
 EXPORT_SYMBOL_GPL(kvm_arch_unregister_noncoherent_dma);
 
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 1e7be1f6ab..5184fde1dc 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -293,6 +293,7 @@ static inline bool kvm_check_has_quirk(struct kvm *kvm, u64 quirk)
 void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);
 
 u64 get_kvmclock_ns(struct kvm *kvm);
+uint64_t kvm_get_wall_clock_epoch(struct kvm *kvm);
 
 int kvm_read_guest_virt(struct kvm_vcpu *vcpu,
 	gva_t addr, void *val, unsigned int bytes,
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 40edf4d197..e53fad915a 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -59,7 +59,7 @@ static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
 		 * This code mirrors kvm_write_wall_clock() except that it writes
 		 * directly through the pfn cache and doesn't mark the page dirty.
 		 */
-		wall_nsec = ktime_get_real_ns() - get_kvmclock_ns(kvm);
+		wall_nsec = kvm_get_wall_clock_epoch(kvm);
 
 		/* It could be invalid again already, so we need to check */
 		read_lock_irq(&gpc->lock);
@@ -98,7 +98,7 @@ static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
 	wc_version = wc->version = (wc->version + 1) | 1;
 	smp_wmb();
 
-	wc->nsec = do_div(wall_nsec,  1000000000);
+	wc->nsec = do_div(wall_nsec, NSEC_PER_SEC);
 	wc->sec = (u32)wall_nsec;
 	*wc_sec_hi = wall_nsec >> 32;
 	smp_wmb();
@@ -134,9 +134,23 @@ static enum hrtimer_restart xen_timer_callback(struct hrtimer *timer)
 {
 	struct kvm_vcpu *vcpu = container_of(timer, struct kvm_vcpu,
 					     arch.xen.timer);
+	struct kvm_xen_evtchn e;
+	int rc;
+
 	if (atomic_read(&vcpu->arch.xen.timer_pending))
 		return HRTIMER_NORESTART;
 
+	e.vcpu_id = vcpu->vcpu_id;
+	e.vcpu_idx = vcpu->vcpu_idx;
+	e.port = vcpu->arch.xen.timer_virq;
+	e.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
+
+	rc = kvm_xen_set_evtchn_fast(&e, vcpu->kvm);
+	if (rc != -EWOULDBLOCK) {
+		vcpu->arch.xen.timer_expires = 0;
+		return HRTIMER_NORESTART;
+	}
+
 	atomic_inc(&vcpu->arch.xen.timer_pending);
 	kvm_make_request(KVM_REQ_UNBLOCK, vcpu);
 	kvm_vcpu_kick(vcpu);
@@ -146,6 +160,14 @@ static enum hrtimer_restart xen_timer_callback(struct hrtimer *timer)
 
 static void kvm_xen_start_timer(struct kvm_vcpu *vcpu, u64 guest_abs, s64 delta_ns)
 {
+	/*
+	 * Avoid races with the old timer firing. Checking timer_expires
+	 * to avoid calling hrtimer_cancel() will only have false positives
+	 * so is fine.
+	 */
+	if (vcpu->arch.xen.timer_expires)
+		hrtimer_cancel(&vcpu->arch.xen.timer);
+
 	atomic_set(&vcpu->arch.xen.timer_pending, 0);
 	vcpu->arch.xen.timer_expires = guest_abs;
 
@@ -1019,9 +1041,36 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 		break;
 
 	case KVM_XEN_VCPU_ATTR_TYPE_TIMER:
+		/*
+		 * Ensure a consistent snapshot of state is captured, with a
+		 * timer either being pending, or the event channel delivered
+		 * to the corresponding bit in the shared_info. Not still
+		 * lurking in the timer_pending flag for deferred delivery.
+		 * Purely as an optimisation, if the timer_expires field is
+		 * zero, that means the timer isn't active (or even in the
+		 * timer_pending flag) and there is no need to cancel it.
+		 */
+		if (vcpu->arch.xen.timer_expires) {
+			hrtimer_cancel(&vcpu->arch.xen.timer);
+			kvm_xen_inject_timer_irqs(vcpu);
+		}
+
 		data->u.timer.port = vcpu->arch.xen.timer_virq;
 		data->u.timer.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
 		data->u.timer.expires_ns = vcpu->arch.xen.timer_expires;
+
+		/*
+		 * The hrtimer may trigger and raise the IRQ immediately,
+		 * while the returned state causes it to be set up and
+		 * raised again on the destination system after migration.
+		 * That's fine, as the guest won't even have had a chance
+		 * to run and handle the interrupt. Asserting an already
+		 * pending event channel is idempotent.
+		 */
+		if (vcpu->arch.xen.timer_expires)
+			hrtimer_start_expires(&vcpu->arch.xen.timer,
+					      HRTIMER_MODE_ABS_HARD);
+
 		r = 0;
 		break;
 
@@ -1374,12 +1423,8 @@ static bool kvm_xen_hcall_vcpu_op(struct kvm_vcpu *vcpu, bool longmode, int cmd,
 			return true;
 		}
 
+		/* A delta <= 0 results in an immediate callback, which is what we want */
 		delta = oneshot.timeout_abs_ns - get_kvmclock_ns(vcpu->kvm);
-		if ((oneshot.flags & VCPU_SSHOTTMR_future) && delta < 0) {
-			*r = -ETIME;
-			return true;
-		}
-
 		kvm_xen_start_timer(vcpu, oneshot.timeout_abs_ns, delta);
 		*r = 0;
 		return true;