diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index eeb006f416..9d9b978e13 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -598,6 +598,16 @@ Aml *aml_named_field(const char *name, unsigned length)
     return var;
 }
 
+/* ACPI 1.0b: 16.2.5.2 Named Objects Encoding: ReservedField */
+Aml *aml_reserved_field(unsigned length)
+{
+    Aml *var = aml_alloc();
+    /* ReservedField  := 0x00 PkgLength */
+    build_append_byte(var->buf, 0x00);
+    build_append_pkg_length(var->buf, length, false);
+    return var;
+}
+
 /* ACPI 1.0b: 16.2.5.2 Named Objects Encoding: DefField */
 Aml *aml_field(const char *name, AmlFieldFlags flags)
 {
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index bf94155316..ea3ece316b 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -29,7 +29,12 @@ typedef enum {
 } AmlIODecode;
 
 typedef enum {
+    aml_any_acc = 0,
     aml_byte_acc = 1,
+    aml_word_acc = 2,
+    aml_dword_acc = 3,
+    aml_qword_acc = 4,
+    aml_buffer_acc = 5,
 } AmlFieldFlags;
 
 typedef enum {
@@ -91,6 +96,7 @@ Aml *aml_io(AmlIODecode dec, uint16_t min_base, uint16_t max_base,
 Aml *aml_operation_region(const char *name, AmlRegionSpace rs,
                           uint32_t offset, uint32_t len);
 Aml *aml_named_field(const char *name, unsigned length);
+Aml *aml_reserved_field(unsigned length);
 Aml *aml_local(int num);
 Aml *aml_string(const char *name_format, ...) GCC_FMT_ATTR(1, 2);
 Aml *aml_equal(Aml *arg1, Aml *arg2);