diff --git a/hw/core/machine.c b/hw/core/machine.c
index fbd91be575..096eb1030f 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -403,6 +403,11 @@ bool machine_usb(MachineState *machine)
     return machine->usb;
 }
 
+bool machine_iommu(MachineState *machine)
+{
+    return machine->iommu;
+}
+
 static const TypeInfo machine_info = {
     .name = TYPE_MACHINE,
     .parent = TYPE_OBJECT,
diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index df60e61d4f..c8827cc000 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -415,7 +415,7 @@ static void mch_realize(PCIDevice *d, Error **errp)
                  PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE, PAM_EXPAN_SIZE);
     }
     /* Intel IOMMU (VT-d) */
-    if (qemu_opt_get_bool(qemu_get_machine_opts(), "iommu", false)) {
+    if (machine_iommu(current_machine)) {
         mch_init_dmar(mch);
     }
 }
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 3ddc449bb6..a12f041d86 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -66,6 +66,7 @@ MachineClass *find_default_machine(void);
 extern MachineState *current_machine;
 
 bool machine_usb(MachineState *machine);
+bool machine_iommu(MachineState *machine);
 
 /**
  * MachineClass: