hw/pci/pci_bridge: Correct pci_bridge_io memory region size

memory_region_set_size() handle the 16 Exabytes limit by
special-casing the UINT64_MAX value. This is not a problem
for the 32-bit maximum, 4 GiB.
By using the UINT32_MAX value, the pci_bridge_io MemoryRegion
ends up missing 1 byte:

  (qemu) info mtree
  memory-region: pci_bridge_io
    0000000000000000-00000000fffffffe (prio 0, i/o): pci_bridge_io
      0000000000000060-0000000000000060 (prio 0, i/o): i8042-data
      0000000000000064-0000000000000064 (prio 0, i/o): i8042-cmd
      00000000000001ce-00000000000001d1 (prio 0, i/o): vbe
      0000000000000378-000000000000037f (prio 0, i/o): parallel
      00000000000003b4-00000000000003b5 (prio 0, i/o): vga
      ...

Fix by using the correct value. We now have:

  memory-region: pci_bridge_io
    0000000000000000-00000000ffffffff (prio 0, i/o): pci_bridge_io
      0000000000000060-0000000000000060 (prio 0, i/o): i8042-data
      0000000000000064-0000000000000064 (prio 0, i/o): i8042-cmd
      ...

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200601142930.29408-4-f4bug@amsat.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

hw/pci/pci_bridge.c

@@ -30,6 +30,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/units.h"
 #include "hw/pci/pci_bridge.h"
 #include "hw/pci/pci_bus.h"
 #include "qemu/module.h"
@@ -381,7 +382,7 @@ void pci_bridge_initfn(PCIDevice *dev, const char *typename)
     memory_region_init(&br->address_space_mem, OBJECT(br), "pci_bridge_pci", UINT64_MAX);
     sec_bus->address_space_io = &br->address_space_io;
     memory_region_init(&br->address_space_io, OBJECT(br), "pci_bridge_io",
-                       UINT32_MAX);
+                       4 * GiB);
     br->windows = pci_bridge_region_init(br);
     QLIST_INIT(&sec_bus->child);
     QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling);