diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 80db152430e4..6ae52926e05a 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -540,6 +540,7 @@ enum kvm_tdx_cmd_id {
 	KVM_TDX_CAPABILITIES = 0,
 	KVM_TDX_INIT_VM,
 	KVM_TDX_INIT_VCPU,
+	KVM_TDX_INIT_MEM_REGION,
 
 	KVM_TDX_CMD_NR_MAX,
 };
@@ -615,4 +616,12 @@ struct kvm_tdx_init_vm {
 	};
 };
 
+#define KVM_TDX_MEASURE_MEMORY_REGION	(1UL << 0)
+
+struct kvm_tdx_init_mem_region {
+	__u64 source_addr;
+	__u64 gpa;
+	__u64 nr_pages;
+};
+
 #endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 37b378bf60df..8e24dd0e3c3c 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5492,6 +5492,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
 out:
 	return r;
 }
+EXPORT_SYMBOL(kvm_mmu_load);
 
 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
 {
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 5378d2c35e27..7c00f71d42af 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -417,6 +417,21 @@ void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int pgd_level)
 	td_vmcs_write64(to_tdx(vcpu), SHARED_EPT_POINTER, root_hpa & PAGE_MASK);
 }
 
+static void tdx_measure_page(struct kvm_tdx *kvm_tdx, hpa_t gpa)
+{
+	struct tdx_module_output out;
+	u64 err;
+	int i;
+
+	for (i = 0; i < PAGE_SIZE; i += TDX_EXTENDMR_CHUNKSIZE) {
+		err = tdh_mr_extend(kvm_tdx->tdr.pa, gpa + i, &out);
+		if (KVM_BUG_ON(err, &kvm_tdx->kvm)) {
+			pr_tdx_error(TDH_MR_EXTEND, err, &out);
+			break;
+		}
+	}
+}
+
 static void tdx_unpin(struct kvm *kvm, kvm_pfn_t pfn)
 {
 	struct page *page = pfn_to_page(pfn);
@@ -431,20 +446,23 @@ static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
 	hpa_t hpa = pfn_to_hpa(pfn);
 	gpa_t gpa = gfn_to_gpa(gfn);
 	struct tdx_module_output out;
+	hpa_t source_pa;
+	bool measure;
 	u64 err;
 
 	if (WARN_ON_ONCE(is_error_noslot_pfn(pfn) ||
 			 !kvm_pfn_to_refcounted_page(pfn)))
 		return 0;
 
-	/* TODO: handle large pages. */
-	if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
-		return -EINVAL;
-
 	/* To prevent page migration, do nothing on mmu notifier. */
 	get_page(pfn_to_page(pfn));
 
+	/* Build-time faults are induced and handled via TDH_MEM_PAGE_ADD. */
 	if (likely(is_td_finalized(kvm_tdx))) {
+		/* TODO: handle large pages. */
+		if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
+			return -EINVAL;
+
 		err = tdh_mem_page_aug(kvm_tdx->tdr.pa, gpa, hpa, &out);
 		if (err == TDX_ERROR_SEPT_BUSY) {
 			tdx_unpin(kvm, pfn);
@@ -453,11 +471,50 @@ static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
 		if (KVM_BUG_ON(err, kvm)) {
 			pr_tdx_error(TDH_MEM_PAGE_AUG, err, &out);
 			tdx_unpin(kvm, pfn);
+			return -EIO;
 		}
 		return 0;
 	}
 
-	/* TODO: tdh_mem_page_add() comes here */
+	/*
+	 * KVM_INIT_MEM_REGION, tdx_init_mem_region(), supports only 4K page
+	 * because tdh_mem_page_add() supports only 4K page.
+	 */
+	if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
+		return -EINVAL;
+
+	/*
+	 * In case of TDP MMU, fault handler can run concurrently.  Note
+	 * 'source_pa' is a TD scope variable, meaning if there are multiple
+	 * threads reaching here with all needing to access 'source_pa', it
+	 * will break.  However fortunately this won't happen, because below
+	 * TDH_MEM_PAGE_ADD code path is only used when VM is being created
+	 * before it is running, using KVM_TDX_INIT_MEM_REGION ioctl (which
+	 * always uses vcpu 0's page table and protected by vcpu->mutex).
+	 */
+	if (KVM_BUG_ON(kvm_tdx->source_pa == INVALID_PAGE, kvm)) {
+		tdx_unpin(kvm, pfn);
+		return -EINVAL;
+	}
+
+	source_pa = kvm_tdx->source_pa & ~KVM_TDX_MEASURE_MEMORY_REGION;
+	measure = kvm_tdx->source_pa & KVM_TDX_MEASURE_MEMORY_REGION;
+	kvm_tdx->source_pa = INVALID_PAGE;
+
+	do {
+		err = tdh_mem_page_add(kvm_tdx->tdr.pa, gpa, hpa, source_pa,
+				       &out);
+		/*
+		 * This path is executed during populating initial guest memory
+		 * image. i.e. before running any vcpu.  Race is rare.
+		 */
+	} while (err == TDX_ERROR_SEPT_BUSY);
+	if (KVM_BUG_ON(err, kvm)) {
+		pr_tdx_error(TDH_MEM_PAGE_ADD, err, &out);
+		tdx_unpin(kvm, pfn);
+		return -EIO;
+	} else if (measure)
+		tdx_measure_page(kvm_tdx, gpa);
 
 	return 0;
 }
@@ -1091,6 +1148,94 @@ void tdx_flush_tlb(struct kvm_vcpu *vcpu)
 		cpu_relax();
 }
 
+#define TDX_SEPT_PFERR	PFERR_WRITE_MASK
+
+static int tdx_init_mem_region(struct kvm *kvm, struct kvm_tdx_cmd *cmd)
+{
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+	struct kvm_tdx_init_mem_region region;
+	struct kvm_vcpu *vcpu;
+	struct page *page;
+	kvm_pfn_t pfn;
+	int idx, ret = 0;
+
+	/* The BSP vCPU must be created before initializing memory regions. */
+	if (!atomic_read(&kvm->online_vcpus))
+		return -EINVAL;
+
+	if (cmd->flags & ~KVM_TDX_MEASURE_MEMORY_REGION)
+		return -EINVAL;
+
+	if (copy_from_user(&region, (void __user *)cmd->data, sizeof(region)))
+		return -EFAULT;
+
+	/* Sanity check */
+	if (!IS_ALIGNED(region.source_addr, PAGE_SIZE) ||
+	    !IS_ALIGNED(region.gpa, PAGE_SIZE) ||
+	    !region.nr_pages ||
+	    region.gpa + (region.nr_pages << PAGE_SHIFT) <= region.gpa ||
+	    !kvm_is_private_gpa(kvm, region.gpa) ||
+	    !kvm_is_private_gpa(kvm, region.gpa + (region.nr_pages << PAGE_SHIFT)))
+		return -EINVAL;
+
+	vcpu = kvm_get_vcpu(kvm, 0);
+	if (mutex_lock_killable(&vcpu->mutex))
+		return -EINTR;
+
+	vcpu_load(vcpu);
+	idx = srcu_read_lock(&kvm->srcu);
+
+	kvm_mmu_reload(vcpu);
+
+	while (region.nr_pages) {
+		if (signal_pending(current)) {
+			ret = -ERESTARTSYS;
+			break;
+		}
+
+		if (need_resched())
+			cond_resched();
+
+
+		/* Pin the source page. */
+		ret = get_user_pages_fast(region.source_addr, 1, 0, &page);
+		if (ret < 0)
+			break;
+		if (ret != 1) {
+			ret = -ENOMEM;
+			break;
+		}
+
+		kvm_tdx->source_pa = pfn_to_hpa(page_to_pfn(page)) |
+				     (cmd->flags & KVM_TDX_MEASURE_MEMORY_REGION);
+
+		pfn = kvm_mmu_map_tdp_page(vcpu, region.gpa, TDX_SEPT_PFERR,
+					   PG_LEVEL_4K);
+		if (is_error_noslot_pfn(pfn) || kvm->vm_bugged)
+			ret = -EFAULT;
+		else
+			ret = 0;
+
+		put_page(page);
+		if (ret)
+			break;
+
+		region.source_addr += PAGE_SIZE;
+		region.gpa += PAGE_SIZE;
+		region.nr_pages--;
+	}
+
+	srcu_read_unlock(&kvm->srcu, idx);
+	vcpu_put(vcpu);
+
+	mutex_unlock(&vcpu->mutex);
+
+	if (copy_to_user((void __user *)cmd->data, &region, sizeof(region)))
+		ret = -EFAULT;
+
+	return ret;
+}
+
 int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 {
 	struct kvm_tdx_cmd tdx_cmd;
@@ -1107,6 +1252,9 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 	case KVM_TDX_INIT_VM:
 		r = tdx_td_init(kvm, &tdx_cmd);
 		break;
+	case KVM_TDX_INIT_MEM_REGION:
+		r = tdx_init_mem_region(kvm, &tdx_cmd);
+		break;
 	default:
 		r = -EINVAL;
 		goto out;
diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
index 80d595c5f96f..686da2321683 100644
--- a/arch/x86/kvm/vmx/tdx.h
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -23,6 +23,8 @@ struct kvm_tdx {
 	u64 xfam;
 	int hkid;
 
+	hpa_t source_pa;
+
 	bool finalized;
 	atomic_t tdh_mem_track;
 
diff --git a/tools/arch/x86/include/uapi/asm/kvm.h b/tools/arch/x86/include/uapi/asm/kvm.h
index 35e3b4aa2e96..37e713ffab72 100644
--- a/tools/arch/x86/include/uapi/asm/kvm.h
+++ b/tools/arch/x86/include/uapi/asm/kvm.h
@@ -540,6 +540,7 @@ enum kvm_tdx_cmd_id {
 	KVM_TDX_CAPABILITIES = 0,
 	KVM_TDX_INIT_VM,
 	KVM_TDX_INIT_VCPU,
+	KVM_TDX_INIT_MEM_REGION,
 
 	KVM_TDX_CMD_NR_MAX,
 };
@@ -617,4 +618,12 @@ struct kvm_tdx_init_vm {
 	};
 };
 
+#define KVM_TDX_MEASURE_MEMORY_REGION	(1UL << 0)
+
+struct kvm_tdx_init_mem_region {
+	__u64 source_addr;
+	__u64 gpa;
+	__u64 nr_pages;
+};
+
 #endif /* _ASM_X86_KVM_H */
