diff --git a/sandbox/vm/include/socks/vm.h b/sandbox/vm/include/socks/vm.h
index 1d71236..96ad17e 100644
--- a/sandbox/vm/include/socks/vm.h
+++ b/sandbox/vm/include/socks/vm.h
@@ -17,10 +17,11 @@ typedef struct vm_object {
 } vm_object_t;
 
 typedef enum vm_zone_id {
-	VM_ZONE_DMA             = 1u,
-	VM_ZONE_NORMAL          = 2u,
-	VM_ZONE_HIGHMEM         = 3u,
-	VM_ZONE_COUNT           = VM_ZONE_HIGHMEM,
+	VM_ZONE_DMA     = 0u,
+	VM_ZONE_NORMAL  = 1u,
+	VM_ZONE_HIGHMEM = 2u,
+	VM_ZONE_MIN     = VM_ZONE_DMA,
+	VM_ZONE_MAX     = VM_ZONE_HIGHMEM,
 } vm_zone_id_t;
 
 typedef enum vm_page_order {
@@ -67,7 +68,7 @@ typedef struct vm_zone {
 } vm_zone_t;
 
 typedef struct vm_pg_data {
-	vm_zone_t pg_zones[VM_ZONE_COUNT];
+	vm_zone_t pg_zones[VM_ZONE_MAX + 1];
 } vm_pg_data_t;
 
 typedef struct vm_region {
@@ -100,6 +101,10 @@ extern kern_status_t vm_bootstrap(const vm_zone_descriptor_t *zones, size_t nr_z
 
 extern void vm_page_init_array();
 extern vm_page_t *vm_page_get(phys_addr_t addr);
+extern phys_addr_t vm_page_get_paddr(vm_page_t *pg);
+extern vm_zone_t *vm_page_get_zone(vm_page_t *pg);
+extern void *vm_page_get_vaddr(vm_page_t *pg);
+extern size_t vm_page_get_pfn(vm_page_t *pg);
 extern size_t vm_page_order_to_bytes(vm_page_order_t order);
 extern size_t vm_page_order_to_pages(vm_page_order_t order);
 extern vm_alignment_t vm_page_order_to_alignment(vm_page_order_t order);
diff --git a/sandbox/vm/vm_page.c b/sandbox/vm/vm_page.c
index 36f9151..0ff38d9 100644
--- a/sandbox/vm/vm_page.c
+++ b/sandbox/vm/vm_page.c
@@ -77,6 +77,22 @@ vm_page_t *vm_page_get(phys_addr_t addr)
 	return pfn < page_array_count ? &page_array[pfn] : NULL;
 }
 
+phys_addr_t vm_page_get_paddr(vm_page_t *pg)
+{
+	return vm_page_get_pfn(pg) * VM_PAGE_SIZE;
+}
+
+void *vm_page_get_vaddr(vm_page_t *pg)
+{
+	/* TODO */
+	return NULL;
+}
+
+size_t vm_page_get_pfn(vm_page_t *pg)
+{
+	return ((uintptr_t)pg - (uintptr_t)page_array) / sizeof *pg;
+}
+
 size_t vm_page_order_to_bytes(vm_page_order_t order)
 {
 	if (order < 0 || order > VM_PAGE_MAX_ORDER) {