diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index c09bd40e0160..01f31957bd7d 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -126,6 +126,7 @@ KVM_X86_OP(alloc_apic_backing_page)
 KVM_X86_OP_NULL(rmp_page_level_adjust)
 KVM_X86_OP(post_map_gfn)
 KVM_X86_OP(post_unmap_gfn)
+KVM_X86_OP(update_protected_guest_state)
 
 #undef KVM_X86_OP
 #undef KVM_X86_OP_NULL
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8773c1f9e45e..11ce66fe1656 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -91,6 +91,7 @@
 #define KVM_REQ_MSR_FILTER_CHANGED	KVM_ARCH_REQ(29)
 #define KVM_REQ_UPDATE_CPU_DIRTY_LOGGING \
 	KVM_ARCH_REQ_FLAGS(30, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
+#define KVM_REQ_UPDATE_PROTECTED_GUEST_STATE	KVM_ARCH_REQ(31)
 
 #define CR0_RESERVED_BITS                                               \
 	(~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
@@ -1468,6 +1469,8 @@ struct kvm_x86_ops {
 
 	int (*post_map_gfn)(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int *token);
 	void (*post_unmap_gfn)(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int token);
+
+	int (*update_protected_guest_state)(struct kvm_vcpu *vcpu);
 };
 
 struct kvm_x86_nested_ops {
diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index a39e31845a33..cf7c88a0d60a 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -218,7 +218,12 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 #define SVM_NESTED_CTL_SEV_ENABLE	BIT(1)
 #define SVM_NESTED_CTL_SEV_ES_ENABLE	BIT(2)
 
-#define SVM_SEV_FEAT_SNP_ACTIVE		BIT(0)
+#define SVM_SEV_FEAT_SNP_ACTIVE			BIT(0)
+#define SVM_SEV_FEAT_RESTRICTED_INJECTION	BIT(3)
+#define SVM_SEV_FEAT_ALTERNATE_INJECTION	BIT(4)
+#define SVM_SEV_FEAT_INT_INJ_MODES		\
+	(SVM_SEV_FEAT_RESTRICTED_INJECTION |	\
+	 SVM_SEV_FEAT_ALTERNATE_INJECTION)
 
 struct vmcb_seg {
 	u16 selector;
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 05f795c30816..151747ec0809 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -649,6 +649,7 @@ static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
 
 static int sev_es_sync_vmsa(struct vcpu_svm *svm)
 {
+	struct kvm_sev_info *sev = &to_kvm_svm(svm->vcpu.kvm)->sev_info;
 	struct sev_es_save_area *save = svm->vmsa;
 
 	/* Check some debug related fields before encrypting the VMSA */
@@ -693,6 +694,12 @@ static int sev_es_sync_vmsa(struct vcpu_svm *svm)
 	if (sev_snp_guest(svm->vcpu.kvm))
 		save->sev_features |= SVM_SEV_FEAT_SNP_ACTIVE;
 
+	/*
+	 * Save the VMSA synced SEV features. For now, they are the same for
+	 * all vCPUs, so just save each time.
+	 */
+	sev->sev_features = save->sev_features;
+
 	return 0;
 }
 
@@ -2760,6 +2767,10 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm, u64 *exit_code)
 		if (!ghcb_sw_scratch_is_valid(ghcb))
 			goto vmgexit_err;
 		break;
+	case SVM_VMGEXIT_AP_CREATION:
+		if (!ghcb_rax_is_valid(ghcb))
+			goto vmgexit_err;
+		break;
 	case SVM_VMGEXIT_NMI_COMPLETE:
 	case SVM_VMGEXIT_AP_HLT_LOOP:
 	case SVM_VMGEXIT_AP_JUMP_TABLE:
@@ -3332,6 +3343,191 @@ static void snp_handle_ext_guest_request(struct vcpu_svm *svm, gpa_t req_gpa, gp
 	svm_set_ghcb_sw_exit_info_2(vcpu, rc);
 }
 
+static int __sev_snp_update_protected_guest_state(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+	kvm_pfn_t pfn;
+
+	WARN_ON(!mutex_is_locked(&svm->snp_vmsa_mutex));
+
+	/* Mark the vCPU as offline and not runnable */
+	vcpu->arch.pv.pv_unhalted = false;
+	vcpu->arch.mp_state = KVM_MP_STATE_STOPPED;
+
+	/* Clear use of the VMSA in the sev_es_init_vmcb() path */
+	svm->vmsa_pa = INVALID_PAGE;
+
+	/* Clear use of the VMSA from the VMCB */
+	svm->vmcb->control.vmsa_pa = INVALID_PAGE;
+
+	if (VALID_PAGE(svm->snp_vmsa_pfn)) {
+		/*
+		 * The snp_vmsa_pfn fields holds the hypervisor physical address
+		 * of the about to be replaced VMSA which will no longer be used
+		 * or referenced, so un-pin it.
+		 */
+		kvm_release_pfn_dirty(svm->snp_vmsa_pfn);
+		svm->snp_vmsa_pfn = INVALID_PAGE;
+	}
+
+	if (VALID_PAGE(svm->snp_vmsa_gpa)) {
+		/*
+		 * The VMSA is referenced by the hypervisor physical address,
+		 * so retrieve the PFN and pin it.
+		 */
+		pfn = gfn_to_pfn(vcpu->kvm, gpa_to_gfn(svm->snp_vmsa_gpa));
+		if (is_error_pfn(pfn))
+			return -EINVAL;
+
+		svm->snp_vmsa_pfn = pfn;
+
+		/* Use the new VMSA in the sev_es_init_vmcb() path */
+		svm->vmsa_pa = pfn_to_hpa(pfn);
+		svm->vmcb->control.vmsa_pa = svm->vmsa_pa;
+
+		/* Mark the vCPU as runnable */
+		vcpu->arch.pv.pv_unhalted = false;
+		vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+	}
+
+	return 0;
+}
+
+/*
+ * Invoked as part of vcpu_enter_guest() event processing.
+ * Expected return values are:
+ *   0 - exit to userspace
+ *   1 - continue vcpu_run() execution loop
+ */
+int sev_snp_update_protected_guest_state(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+	int ret;
+
+	mutex_lock(&svm->snp_vmsa_mutex);
+
+	ret = __sev_snp_update_protected_guest_state(vcpu);
+	if (ret)
+		vcpu_unimpl(vcpu, "snp: AP state update failed\n");
+
+	mutex_unlock(&svm->snp_vmsa_mutex);
+
+	return ret ? 0 : 1;
+}
+
+/*
+ * Invoked as part of svm_vcpu_reset() processing of an init event.
+ */
+void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+	int ret;
+
+	if (!sev_snp_guest(vcpu->kvm))
+		return;
+
+	mutex_lock(&svm->snp_vmsa_mutex);
+
+	if (!svm->snp_vmsa_update_on_init)
+		goto unlock;
+
+	svm->snp_vmsa_update_on_init = false;
+
+	ret = __sev_snp_update_protected_guest_state(vcpu);
+	if (ret)
+		vcpu_unimpl(vcpu, "snp: AP state update on init failed\n");
+
+unlock:
+	mutex_unlock(&svm->snp_vmsa_mutex);
+}
+
+static int sev_snp_ap_creation(struct vcpu_svm *svm)
+{
+	struct kvm_sev_info *sev = &to_kvm_svm(svm->vcpu.kvm)->sev_info;
+	struct kvm_vcpu *vcpu = &svm->vcpu;
+	struct kvm_vcpu *target_vcpu;
+	struct vcpu_svm *target_svm;
+	unsigned int request;
+	unsigned int apic_id;
+	bool kick;
+	int ret;
+
+	request = lower_32_bits(svm->vmcb->control.exit_info_1);
+	apic_id = upper_32_bits(svm->vmcb->control.exit_info_1);
+
+	/* Validate the APIC ID */
+	target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, apic_id);
+	if (!target_vcpu) {
+		vcpu_unimpl(vcpu, "vmgexit: invalid AP APIC ID [%#x] from guest\n",
+			    apic_id);
+		return -EINVAL;
+	}
+
+	ret = 0;
+
+	target_svm = to_svm(target_vcpu);
+
+	/*
+	 * We have a valid target vCPU, so the vCPU will be kicked unless the
+	 * request is for CREATE_ON_INIT. For any errors at this stage, the
+	 * kick will place the vCPU in an non-runnable state.
+	 */
+	kick = true;
+
+	mutex_lock(&target_svm->snp_vmsa_mutex);
+
+	target_svm->snp_vmsa_gpa = INVALID_PAGE;
+	target_svm->snp_vmsa_update_on_init = false;
+
+	/* Interrupt injection mode shouldn't change for AP creation */
+	if (request < SVM_VMGEXIT_AP_DESTROY) {
+		u64 sev_features;
+
+		sev_features = vcpu->arch.regs[VCPU_REGS_RAX];
+		sev_features ^= sev->sev_features;
+		if (sev_features & SVM_SEV_FEAT_INT_INJ_MODES) {
+			vcpu_unimpl(vcpu, "vmgexit: invalid AP injection mode [%#lx] from guest\n",
+				    vcpu->arch.regs[VCPU_REGS_RAX]);
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+
+	switch (request) {
+	case SVM_VMGEXIT_AP_CREATE_ON_INIT:
+		kick = false;
+		target_svm->snp_vmsa_update_on_init = true;
+		fallthrough;
+	case SVM_VMGEXIT_AP_CREATE:
+		if (!page_address_valid(vcpu, svm->vmcb->control.exit_info_2)) {
+			vcpu_unimpl(vcpu, "vmgexit: invalid AP VMSA address [%#llx] from guest\n",
+				    svm->vmcb->control.exit_info_2);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		target_svm->snp_vmsa_gpa = svm->vmcb->control.exit_info_2;
+		break;
+	case SVM_VMGEXIT_AP_DESTROY:
+		break;
+	default:
+		vcpu_unimpl(vcpu, "vmgexit: invalid AP creation request [%#x] from guest\n",
+			    request);
+		ret = -EINVAL;
+		break;
+	}
+
+out:
+	mutex_unlock(&target_svm->snp_vmsa_mutex);
+
+	if (kick) {
+		kvm_make_request(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, target_vcpu);
+		kvm_vcpu_kick(target_vcpu);
+	}
+
+	return ret;
+}
+
 static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
 {
 	struct vmcb_control_area *control = &svm->vmcb->control;
@@ -3589,6 +3785,18 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
 		ret = 1;
 		break;
 	}
+	case SVM_VMGEXIT_AP_CREATION:
+		ret = sev_snp_ap_creation(svm);
+		if (ret) {
+			svm_set_ghcb_sw_exit_info_1(vcpu, 1);
+			svm_set_ghcb_sw_exit_info_2(vcpu,
+						    X86_TRAP_GP |
+						    SVM_EVTINJ_TYPE_EXEPT |
+						    SVM_EVTINJ_VALID);
+		}
+
+		ret = 1;
+		break;
 	case SVM_VMGEXIT_UNSUPPORTED_EVENT:
 		vcpu_unimpl(vcpu,
 			    "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",
@@ -3663,6 +3871,9 @@ void sev_es_create_vcpu(struct vcpu_svm *svm)
 	set_ghcb_msr(svm, GHCB_MSR_SEV_INFO(GHCB_VERSION_MAX,
 					    GHCB_VERSION_MIN,
 					    sev_enc_bit));
+
+	mutex_init(&svm->snp_vmsa_mutex);
+	svm->snp_vmsa_pfn = INVALID_PAGE;
 }
 
 void sev_es_prepare_guest_switch(struct vcpu_svm *svm, unsigned int cpu)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index be820eb999fb..29e7666a710b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1336,7 +1336,9 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 	svm->spec_ctrl = 0;
 	svm->virt_spec_ctrl = 0;
 
-	if (!init_event) {
+	if (init_event) {
+		sev_snp_init_protected_guest_state(vcpu);
+	} else {
 		vcpu->arch.apic_base = APIC_DEFAULT_PHYS_BASE |
 				       MSR_IA32_APICBASE_ENABLE;
 		if (kvm_vcpu_is_reset_bsp(vcpu))
@@ -4697,6 +4699,8 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
 
 	.post_map_gfn = sev_post_map_gfn,
 	.post_unmap_gfn = sev_post_unmap_gfn,
+
+	.update_protected_guest_state = sev_snp_update_protected_guest_state,
 };
 
 static struct kvm_x86_init_ops svm_init_ops __initdata = {
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 9bf6404142dd..59044b3a7c7a 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -94,6 +94,8 @@ struct kvm_sev_info {
 	struct srcu_struct psc_srcu;
 	void *snp_certs_data;
 	struct mutex guest_req_lock;
+
+	u64 sev_features;	/* Features set at VMSA creation */
 };
 
 struct kvm_svm {
@@ -221,6 +223,11 @@ struct vcpu_svm {
 	u64 ghcb_sw_exit_info_2;
 
 	u64 ghcb_registered_gpa;
+
+	struct mutex snp_vmsa_mutex;
+	gpa_t snp_vmsa_gpa;
+	kvm_pfn_t snp_vmsa_pfn;
+	bool snp_vmsa_update_on_init;	/* SEV-SNP AP Creation on INIT-SIPI */
 };
 
 struct svm_cpu_data {
@@ -630,6 +637,8 @@ void sev_rmp_page_level_adjust(struct kvm *kvm, kvm_pfn_t pfn, int *level);
 int sev_post_map_gfn(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int *token);
 void sev_post_unmap_gfn(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int token);
 void handle_rmp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code);
+void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu);
+int sev_snp_update_protected_guest_state(struct kvm_vcpu *vcpu);
 
 /* vmenter.S */
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bf4389ffc88f..dbb8362cc576 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9576,6 +9576,16 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 
 		if (kvm_check_request(KVM_REQ_UPDATE_CPU_DIRTY_LOGGING, vcpu))
 			static_call(kvm_x86_update_cpu_dirty_logging)(vcpu);
+
+		if (kvm_check_request(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, vcpu)) {
+			r = static_call(kvm_x86_update_protected_guest_state)(vcpu);
+			if (!r) {
+				vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+				goto out;
+			} else if (vcpu->arch.mp_state != KVM_MP_STATE_RUNNABLE) {
+				goto out;
+			}
+		}
 	}
 
 	if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win ||
@@ -11656,7 +11666,8 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
 	if (!list_empty_careful(&vcpu->async_pf.done))
 		return true;
 
-	if (kvm_apic_has_events(vcpu))
+	if (kvm_apic_has_events(vcpu) ||
+	    kvm_test_request(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, vcpu))
 		return true;
 
 	if (vcpu->arch.pv.pv_unhalted)
