diff --git a/xen/arch/x86/acpi/boot.c b/xen/arch/x86/acpi/boot.c
index 8e6c96dcf6..e89c2e9009 100644
--- a/xen/arch/x86/acpi/boot.c
+++ b/xen/arch/x86/acpi/boot.c
@@ -724,6 +724,8 @@ int __init acpi_boot_init(void)
 
 	acpi_table_parse(ACPI_SIG_HPET, acpi_parse_hpet);
 
+	acpi_mmcfg_init();
+
 	acpi_dmar_init();
 
 	erst_init();
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 261861e1ed..dd11815e2d 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1506,6 +1506,9 @@ void __init noreturn __start_xen(unsigned long mbi_p)
 
     generic_apic_probe();
 
+    mmio_ro_ranges = rangeset_new(NULL, "r/o mmio ranges",
+                                  RANGESETF_prettyprint_hex);
+
     acpi_boot_init();
 
     if ( smp_found_config )
@@ -1538,9 +1541,6 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     /* Low mappings were only needed for some BIOS table parsing. */
     zap_low_mappings();
 
-    mmio_ro_ranges = rangeset_new(NULL, "r/o mmio ranges",
-                                  RANGESETF_prettyprint_hex);
-
     init_apic_mappings();
 
     normalise_cpu_order();
@@ -1611,8 +1611,6 @@ void __init noreturn __start_xen(unsigned long mbi_p)
 
     vesa_mtrr_init();
 
-    acpi_mmcfg_init();
-
     early_msi_init();
 
     iommu_setup();    /* setup iommu if available */