sysbus: add helpers to add and delete memory regions to the system bus

Reviewed-by: Richard Henderson  <rth@twiddle.net>
Signed-off-by: Avi Kivity <avi@redhat.com>

hw/sysbus.c

@@ -261,3 +261,25 @@ static char *sysbus_get_fw_dev_path(DeviceState *dev)
 
     return strdup(path);
 }
+
+void sysbus_add_memory(SysBusDevice *dev, target_phys_addr_t addr,
+                       MemoryRegion *mem)
+{
+    memory_region_add_subregion(get_system_memory(), addr, mem);
+}
+
+void sysbus_del_memory(SysBusDevice *dev, MemoryRegion *mem)
+{
+    memory_region_del_subregion(get_system_memory(), mem);
+}
+
+void sysbus_add_io(SysBusDevice *dev, target_phys_addr_t addr,
+                       MemoryRegion *mem)
+{
+    memory_region_add_subregion(get_system_io(), addr, mem);
+}
+
+void sysbus_del_io(SysBusDevice *dev, MemoryRegion *mem)
+{
+    memory_region_del_subregion(get_system_io(), mem);
+}

hw/sysbus.h

@@ -58,6 +58,12 @@ void sysbus_init_ioports(SysBusDevice *dev, pio_addr_t ioport, pio_addr_t size);
 
 void sysbus_connect_irq(SysBusDevice *dev, int n, qemu_irq irq);
 void sysbus_mmio_map(SysBusDevice *dev, int n, target_phys_addr_t addr);
+void sysbus_add_memory(SysBusDevice *dev, target_phys_addr_t addr,
+                       MemoryRegion *mem);
+void sysbus_del_memory(SysBusDevice *dev, MemoryRegion *mem);
+void sysbus_add_io(SysBusDevice *dev, target_phys_addr_t addr,
+                   MemoryRegion *mem);
+void sysbus_del_io(SysBusDevice *dev, MemoryRegion *mem);
 
 /* Legacy helper function for creating devices.  */
 DeviceState *sysbus_create_varargs(const char *name,