diff --git a/hw/core/loader.c b/hw/core/loader.c
index eb67f05ee2..6b69852479 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -51,12 +51,10 @@
 #include "hw/nvram/fw_cfg.h"
 #include "exec/memory.h"
 #include "exec/address-spaces.h"
+#include "hw/boards.h"
 
 #include <zlib.h>
 
-bool option_rom_has_mr = false;
-bool rom_file_has_mr = true;
-
 static int roms_loaded;
 
 /* return the size or -1 if error */
@@ -754,6 +752,7 @@ int rom_add_file(const char *file, const char *fw_dir,
                  hwaddr addr, int32_t bootindex,
                  bool option_rom)
 {
+    MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
     Rom *rom;
     int rc, fd = -1;
     char devpath[100];
@@ -810,7 +809,7 @@ int rom_add_file(const char *file, const char *fw_dir,
                  basename);
         snprintf(devpath, sizeof(devpath), "/rom@%s", fw_file_name);
 
-        if ((!option_rom || option_rom_has_mr) && rom_file_has_mr) {
+        if ((!option_rom || mc->option_rom_has_mr) && mc->rom_file_has_mr) {
             data = rom_set_mr(rom, OBJECT(fw_cfg), devpath);
         } else {
             data = rom->data;
@@ -838,6 +837,7 @@ MemoryRegion *rom_add_blob(const char *name, const void *blob, size_t len,
                    size_t max_len, hwaddr addr, const char *fw_file_name,
                    FWCfgReadCallback fw_callback, void *callback_opaque)
 {
+    MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
     Rom *rom;
     MemoryRegion *mr = NULL;
 
@@ -855,7 +855,7 @@ MemoryRegion *rom_add_blob(const char *name, const void *blob, size_t len,
 
         snprintf(devpath, sizeof(devpath), "/rom@%s", fw_file_name);
 
-        if (rom_file_has_mr) {
+        if (mc->rom_file_has_mr) {
             data = rom_set_mr(rom, OBJECT(fw_cfg), devpath);
             mr = rom->mr;
         } else {
diff --git a/hw/core/machine.c b/hw/core/machine.c
index 82be54e751..c46ddc7d15 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -342,6 +342,7 @@ static void machine_class_init(ObjectClass *oc, void *data)
 
     /* Default 128 MB as guest ram size */
     mc->default_ram_size = 128 * M_BYTE;
+    mc->rom_file_has_mr = true;
 }
 
 static void machine_class_base_init(ObjectClass *oc, void *data)
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index f058b3cb00..7d847b247d 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -320,14 +320,12 @@ static void pc_compat_2_0(MachineState *machine)
 static void pc_compat_1_7(MachineState *machine)
 {
     pc_compat_2_0(machine);
-    option_rom_has_mr = true;
     x86_cpu_change_kvm_default("x2apic", NULL);
 }
 
 static void pc_compat_1_6(MachineState *machine)
 {
     pc_compat_1_7(machine);
-    rom_file_has_mr = false;
 }
 
 static void pc_compat_1_5(MachineState *machine)
@@ -361,8 +359,6 @@ static void pc_compat_0_13(MachineState *machine)
 
 static void pc_init_isa(MachineState *machine)
 {
-    option_rom_has_mr = true;
-    rom_file_has_mr = false;
     if (!machine->cpu_model) {
         machine->cpu_model = "486";
     }
@@ -527,6 +523,7 @@ static void pc_i440fx_1_7_machine_options(MachineClass *m)
     pc_i440fx_2_0_machine_options(m);
     m->hw_version = "1.7.0";
     m->default_machine_opts = NULL;
+    m->option_rom_has_mr = true;
     SET_MACHINE_COMPAT(m, PC_COMPAT_1_7);
     pcmc->smbios_defaults = false;
     pcmc->gigabyte_align = false;
@@ -542,6 +539,7 @@ static void pc_i440fx_1_6_machine_options(MachineClass *m)
     PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
     pc_i440fx_1_7_machine_options(m);
     m->hw_version = "1.6.0";
+    m->rom_file_has_mr = false;
     SET_MACHINE_COMPAT(m, PC_COMPAT_1_6);
     pcmc->has_acpi_build = false;
 }
@@ -1026,6 +1024,8 @@ static void isapc_machine_options(MachineClass *m)
     PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
     m->desc = "ISA-only PC";
     m->max_cpus = 1;
+    m->option_rom_has_mr = true;
+    m->rom_file_has_mr = false;
     pcmc->pci_enabled = false;
     pcmc->has_acpi_build = false;
     pcmc->smbios_defaults = false;
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 2f644f951d..6aaa0eedb0 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -304,14 +304,12 @@ static void pc_compat_2_0(MachineState *machine)
 static void pc_compat_1_7(MachineState *machine)
 {
     pc_compat_2_0(machine);
-    option_rom_has_mr = true;
     x86_cpu_change_kvm_default("x2apic", NULL);
 }
 
 static void pc_compat_1_6(MachineState *machine)
 {
     pc_compat_1_7(machine);
-    rom_file_has_mr = false;
 }
 
 static void pc_compat_1_5(MachineState *machine)
@@ -434,6 +432,7 @@ static void pc_q35_1_7_machine_options(MachineClass *m)
     pc_q35_2_0_machine_options(m);
     m->hw_version = "1.7.0";
     m->default_machine_opts = NULL;
+    m->option_rom_has_mr = true;
     SET_MACHINE_COMPAT(m, PC_COMPAT_1_7);
     pcmc->smbios_defaults = false;
     pcmc->gigabyte_align = false;
@@ -448,6 +447,7 @@ static void pc_q35_1_6_machine_options(MachineClass *m)
     PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
     pc_q35_machine_options(m);
     m->hw_version = "1.6.0";
+    m->rom_file_has_mr = false;
     SET_MACHINE_COMPAT(m, PC_COMPAT_1_6);
     pcmc->has_acpi_build = false;
 }
diff --git a/include/hw/boards.h b/include/hw/boards.h
index f19df9769c..051db5ed25 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -93,6 +93,8 @@ struct MachineClass {
     GlobalProperty *compat_props;
     const char *hw_version;
     ram_addr_t default_ram_size;
+    bool option_rom_has_mr;
+    bool rom_file_has_mr;
 
     HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
                                            DeviceState *dev);