diff --git a/tools/libxl/libxl_arch.h b/tools/libxl/libxl_arch.h
index 8cb9ba7..a066bbd 100644
--- a/tools/libxl/libxl_arch.h
+++ b/tools/libxl/libxl_arch.h
@@ -66,6 +66,10 @@ _hidden
 void libxl__arch_domain_build_info_acpi_setdefault(
                                         libxl_domain_build_info *b_info);
 
+_hidden
+int libxl__arch_memory_constant(libxl__gc *gc, libxl_domain_build_info *info,
+                                libxl__domain_build_state *state);
+
 #if defined(__i386__) || defined(__x86_64__)
 
 #define LAPIC_BASE_ADDRESS  0xfee00000
diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
index 913f401..932e674 100644
--- a/tools/libxl/libxl_arm.c
+++ b/tools/libxl/libxl_arm.c
@@ -106,6 +106,22 @@ int libxl__arch_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
     return 0;
 }
 
+int libxl__arch_memory_constant(libxl__gc *gc, libxl_domain_build_info *info,
+                                libxl__domain_build_state *state)
+{
+    int size;
+
+    if (libxl_defbool_val(info->acpi)) {
+        size = libxl__get_acpi_size(gc, info, state);
+        if (size < 0)
+            return ERROR_FAIL;
+
+        return DIV_ROUNDUP(size, 1024);
+    }
+
+    return 0;
+}
+
 static struct arch_info {
     const char *guest_type;
     const char *timer_compat;
diff --git a/tools/libxl/libxl_arm.h b/tools/libxl/libxl_arm.h
index a91ff93..37b1f15 100644
--- a/tools/libxl/libxl_arm.h
+++ b/tools/libxl/libxl_arm.h
@@ -24,6 +24,10 @@ int libxl__prepare_acpi(libxl__gc *gc, libxl_domain_build_info *info,
                         libxl__domain_build_state *state,
                         struct xc_dom_image *dom);
 
+_hidden
+int libxl__get_acpi_size(libxl__gc *gc, libxl_domain_build_info *info,
+                         libxl__domain_build_state *state);
+
 static inline uint64_t libxl__compute_mpdir(unsigned int cpuid)
 {
     /*
diff --git a/tools/libxl/libxl_arm_acpi.c b/tools/libxl/libxl_arm_acpi.c
index 9c4005f..0d4092d 100644
--- a/tools/libxl/libxl_arm_acpi.c
+++ b/tools/libxl/libxl_arm_acpi.c
@@ -94,6 +94,26 @@ static int libxl__estimate_madt_size(libxl__gc *gc,
     return rc;
 }
 
+int libxl__get_acpi_size(libxl__gc *gc, libxl_domain_build_info *info,
+                         libxl__domain_build_state *state)
+{
+    int size;
+
+    size = libxl__estimate_madt_size(gc, info, &state->config);
+    if (size < 0)
+        goto out;
+
+    size = ROUNDUP(size, 3) +
+           ROUNDUP(sizeof(struct acpi_table_rsdp), 3) +
+           ROUNDUP(sizeof(struct acpi_table_xsdt), 3) +
+           ROUNDUP(sizeof(struct acpi_table_gtdt), 3) +
+           ROUNDUP(sizeof(struct acpi_table_fadt), 3) +
+           ROUNDUP(sizeof(dsdt_anycpu_arm_len), 3);
+
+out:
+    return size;
+}
+
 static int libxl__estimate_acpi_size(libxl__gc *gc,
                                      libxl_domain_build_info *info,
                                      struct xc_dom_image *dom,
diff --git a/tools/libxl/libxl_arm_no_acpi.c b/tools/libxl/libxl_arm_no_acpi.c
index e7f7411..5eeb825 100644
--- a/tools/libxl/libxl_arm_no_acpi.c
+++ b/tools/libxl/libxl_arm_no_acpi.c
@@ -25,6 +25,12 @@ int libxl__prepare_acpi(libxl__gc *gc, libxl_domain_build_info *info,
     return ERROR_FAIL;
 }
 
+int libxl__get_acpi_size(libxl__gc *gc, libxl_domain_build_info *info,
+                         libxl__domain_build_state *state)
+{
+    return ERROR_FAIL;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 2924629..118beab 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -408,8 +408,15 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
         }
     }
 
+
+    rc = libxl__arch_memory_constant(gc, info, state);
+    if (rc < 0) {
+        LOGE(ERROR, "Couldn't get arch constant memory size");
+        return ERROR_FAIL;
+    }
+
     if (xc_domain_setmaxmem(ctx->xch, domid, info->target_memkb +
-        LIBXL_MAXMEM_CONSTANT) < 0) {
+        LIBXL_MAXMEM_CONSTANT + rc) < 0) {
         LOGE(ERROR, "Couldn't set max memory");
         return ERROR_FAIL;
     }
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index cb6d9e0..8366fee 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -128,6 +128,8 @@
 #define ROUNDUP(_val, _order)                                           \
     (((unsigned long)(_val)+(1UL<<(_order))-1) & ~((1UL<<(_order))-1))
 
+#define DIV_ROUNDUP(n, d) (((n) + (d) - 1) / (d))
+
 #define MASK_EXTR(v, m) (((v) & (m)) / ((m) & -(m)))
 #define MASK_INSR(v, m) (((v) * ((m) & -(m))) & (m))
 
diff --git a/tools/libxl/libxl_x86.c b/tools/libxl/libxl_x86.c
index f69f3c2..0a86040 100644
--- a/tools/libxl/libxl_x86.c
+++ b/tools/libxl/libxl_x86.c
@@ -358,6 +358,12 @@ out:
     return ret;
 }
 
+int libxl__arch_memory_constant(libxl__gc *gc, libxl_domain_build_info *info,
+                                libxl__domain_build_state *state)
+{
+    return 0;
+}
+
 int libxl__arch_domain_init_hw_description(libxl__gc *gc,
                                            libxl_domain_build_info *info,
                                            libxl__domain_build_state *state,
