diff --git a/hw/cs4231a.c b/hw/cs4231a.c
index 4d5ce5c..598f032 100644
--- a/hw/cs4231a.c
+++ b/hw/cs4231a.c
@@ -645,6 +645,7 @@ static int cs4231a_initfn (ISADevice *dev)
     isa_init_irq (dev, &s->pic, s->irq);
 
     for (i = 0; i < 4; i++) {
+        isa_init_ioport(dev, i);
         register_ioport_write (s->port + i, 1, 1, cs_write, s);
         register_ioport_read (s->port + i, 1, 1, cs_read, s);
     }
diff --git a/hw/fdc.c b/hw/fdc.c
index a467c4b..22fb64a 100644
--- a/hw/fdc.c
+++ b/hw/fdc.c
@@ -1983,6 +1983,9 @@ static int isabus_fdc_init1(ISADevice *dev)
                           &fdctrl_write_port, fdctrl);
     register_ioport_write(iobase + 0x07, 1, 1,
                           &fdctrl_write_port, fdctrl);
+    isa_init_ioport_range(dev, iobase, 6);
+    isa_init_ioport(dev, iobase + 7);
+
     isa_init_irq(&isa->busdev, &fdctrl->irq, isairq);
     fdctrl->dma_chann = dma_chann;
 
diff --git a/hw/gus.c b/hw/gus.c
index e9016d8..ff9e7c7 100644
--- a/hw/gus.c
+++ b/hw/gus.c
@@ -264,20 +264,24 @@ static int gus_initfn (ISADevice *dev)
 
     register_ioport_write (s->port, 1, 1, gus_writeb, s);
     register_ioport_write (s->port, 1, 2, gus_writew, s);
+    isa_init_ioport_range(dev, s->port, 2);
 
     register_ioport_read ((s->port + 0x100) & 0xf00, 1, 1, gus_readb, s);
     register_ioport_read ((s->port + 0x100) & 0xf00, 1, 2, gus_readw, s);
+    isa_init_ioport_range(dev, (s->port + 0x100) & 0xf00, 2);
 
     register_ioport_write (s->port + 6, 10, 1, gus_writeb, s);
     register_ioport_write (s->port + 6, 10, 2, gus_writew, s);
     register_ioport_read (s->port + 6, 10, 1, gus_readb, s);
     register_ioport_read (s->port + 6, 10, 2, gus_readw, s);
+    isa_init_ioport_range(dev, s->port + 6, 10);
 
 
     register_ioport_write (s->port + 0x100, 8, 1, gus_writeb, s);
     register_ioport_write (s->port + 0x100, 8, 2, gus_writew, s);
     register_ioport_read (s->port + 0x100, 8, 1, gus_readb, s);
     register_ioport_read (s->port + 0x100, 8, 2, gus_readw, s);
+    isa_init_ioport_range(dev, s->port + 0x100, 8);
 
     DMA_register_channel (s->emu.gusdma, GUS_read_DMA, s);
     s->emu.himemaddr = s->himem;
diff --git a/hw/ide/isa.c b/hw/ide/isa.c
index 9856435..4206afd 100644
--- a/hw/ide/isa.c
+++ b/hw/ide/isa.c
@@ -70,6 +70,8 @@ static int isa_ide_initfn(ISADevice *dev)
     ide_bus_new(&s->bus, &s->dev.qdev);
     ide_init_ioport(&s->bus, s->iobase, s->iobase2);
     isa_init_irq(dev, &s->irq, s->isairq);
+    isa_init_ioport_range(dev, s->iobase, 8);
+    isa_init_ioport(dev, s->iobase2);
     ide_init2(&s->bus, s->irq);
     vmstate_register(&dev->qdev, 0, &vmstate_ide_isa, s);
     return 0;
diff --git a/hw/isa-bus.c b/hw/isa-bus.c
index 26036e0..c0ac7e9 100644
--- a/hw/isa-bus.c
+++ b/hw/isa-bus.c
@@ -92,6 +92,31 @@ void isa_init_irq(ISADevice *dev, qemu_irq *p, int isairq)
     dev->nirqs++;
 }
 
+static void isa_init_ioport_one(ISADevice *dev, uint16_t ioport)
+{
+    assert(dev->nioports < ARRAY_SIZE(dev->ioports));
+    dev->ioports[dev->nioports++] = ioport;
+}
+
+static int isa_cmp_ports(const void *p1, const void *p2)
+{
+    return *(uint16_t*)p1 - *(uint16_t*)p2;
+}
+
+void isa_init_ioport_range(ISADevice *dev, uint16_t start, uint16_t length)
+{
+    int i;
+    for (i = start; i < start + length; i++) {
+        isa_init_ioport_one(dev, i);
+    }
+    qsort(dev->ioports, dev->nioports, sizeof(dev->ioports[0]), isa_cmp_ports);
+}
+
+void isa_init_ioport(ISADevice *dev, uint16_t ioport)
+{
+    isa_init_ioport_range(dev, ioport, 1);
+}
+
 static int isa_qdev_init(DeviceState *qdev, DeviceInfo *base)
 {
     ISADevice *dev = DO_UPCAST(ISADevice, qdev, qdev);
diff --git a/hw/isa.h b/hw/isa.h
index aaf0272..4794b76 100644
--- a/hw/isa.h
+++ b/hw/isa.h
@@ -14,6 +14,8 @@ struct ISADevice {
     DeviceState qdev;
     uint32_t isairq[2];
     int nirqs;
+    uint16_t ioports[32];
+    int nioports;
 };
 
 typedef int (*isa_qdev_initfn)(ISADevice *dev);
@@ -26,6 +28,8 @@ ISABus *isa_bus_new(DeviceState *dev);
 void isa_bus_irqs(qemu_irq *irqs);
 qemu_irq isa_reserve_irq(int isairq);
 void isa_init_irq(ISADevice *dev, qemu_irq *p, int isairq);
+void isa_init_ioport(ISADevice *dev, uint16_t ioport);
+void isa_init_ioport_range(ISADevice *dev, uint16_t start, uint16_t length);
 void isa_qdev_register(ISADeviceInfo *info);
 ISADevice *isa_create(const char *name);
 ISADevice *isa_create_simple(const char *name);
diff --git a/hw/m48t59.c b/hw/m48t59.c
index c7492a6..75a94e1 100644
--- a/hw/m48t59.c
+++ b/hw/m48t59.c
@@ -680,6 +680,7 @@ M48t59State *m48t59_init_isa(uint32_t io_base, uint16_t size, int type)
     if (io_base != 0) {
         register_ioport_read(io_base, 0x04, 1, NVRAM_readb, s);
         register_ioport_write(io_base, 0x04, 1, NVRAM_writeb, s);
+        isa_init_ioport_range(dev, io_base, 4);
     }
 
     return s;
diff --git a/hw/mc146818rtc.c b/hw/mc146818rtc.c
index 2b91fa8..6466aff 100644
--- a/hw/mc146818rtc.c
+++ b/hw/mc146818rtc.c
@@ -605,6 +605,7 @@ static int rtc_initfn(ISADevice *dev)
 
     register_ioport_write(base, 2, 1, cmos_ioport_write, s);
     register_ioport_read(base, 2, 1, cmos_ioport_read, s);
+    isa_init_ioport_range(dev, base, 2);
 
     qdev_set_legacy_instance_id(&dev->qdev, base, 2);
     qemu_register_reset(rtc_reset, s);
diff --git a/hw/ne2000-isa.c b/hw/ne2000-isa.c
index 03a5a1f..3ff0d89 100644
--- a/hw/ne2000-isa.c
+++ b/hw/ne2000-isa.c
@@ -68,14 +68,17 @@ static int isa_ne2000_initfn(ISADevice *dev)
 
     register_ioport_write(isa->iobase, 16, 1, ne2000_ioport_write, s);
     register_ioport_read(isa->iobase, 16, 1, ne2000_ioport_read, s);
+    isa_init_ioport_range(dev, isa->iobase, 16);
 
     register_ioport_write(isa->iobase + 0x10, 1, 1, ne2000_asic_ioport_write, s);
     register_ioport_read(isa->iobase + 0x10, 1, 1, ne2000_asic_ioport_read, s);
     register_ioport_write(isa->iobase + 0x10, 2, 2, ne2000_asic_ioport_write, s);
     register_ioport_read(isa->iobase + 0x10, 2, 2, ne2000_asic_ioport_read, s);
+    isa_init_ioport_range(dev, isa->iobase + 0x10, 2);
 
     register_ioport_write(isa->iobase + 0x1f, 1, 1, ne2000_reset_ioport_write, s);
     register_ioport_read(isa->iobase + 0x1f, 1, 1, ne2000_reset_ioport_read, s);
+    isa_init_ioport(dev, isa->iobase + 0x1f);
 
     isa_init_irq(dev, &s->irq, isa->isairq);
 
diff --git a/hw/parallel.c b/hw/parallel.c
index 6b11672..6270b53 100644
--- a/hw/parallel.c
+++ b/hw/parallel.c
@@ -481,16 +481,21 @@ static int parallel_isa_initfn(ISADevice *dev)
     if (s->hw_driver) {
         register_ioport_write(base, 8, 1, parallel_ioport_write_hw, s);
         register_ioport_read(base, 8, 1, parallel_ioport_read_hw, s);
+        isa_init_ioport_range(dev, base, 8);
+
         register_ioport_write(base+4, 1, 2, parallel_ioport_eppdata_write_hw2, s);
         register_ioport_read(base+4, 1, 2, parallel_ioport_eppdata_read_hw2, s);
         register_ioport_write(base+4, 1, 4, parallel_ioport_eppdata_write_hw4, s);
         register_ioport_read(base+4, 1, 4, parallel_ioport_eppdata_read_hw4, s);
+        isa_init_ioport(dev, base+4);
         register_ioport_write(base+0x400, 8, 1, parallel_ioport_ecp_write, s);
         register_ioport_read(base+0x400, 8, 1, parallel_ioport_ecp_read, s);
+        isa_init_ioport_range(dev, base+0x400, 8);
     }
     else {
         register_ioport_write(base, 8, 1, parallel_ioport_write_sw, s);
         register_ioport_read(base, 8, 1, parallel_ioport_read_sw, s);
+        isa_init_ioport_range(dev, base, 8);
     }
     return 0;
 }
diff --git a/hw/pckbd.c b/hw/pckbd.c
index 6e4e406..e736505 100644
--- a/hw/pckbd.c
+++ b/hw/pckbd.c
@@ -484,10 +484,13 @@ static int i8042_initfn(ISADevice *dev)
 
     register_ioport_read(0x60, 1, 1, kbd_read_data, s);
     register_ioport_write(0x60, 1, 1, kbd_write_data, s);
+    isa_init_ioport(dev, 0x60);
     register_ioport_read(0x64, 1, 1, kbd_read_status, s);
     register_ioport_write(0x64, 1, 1, kbd_write_command, s);
+    isa_init_ioport(dev, 0x64);
     register_ioport_read(0x92, 1, 1, ioport92_read, s);
     register_ioport_write(0x92, 1, 1, ioport92_write, s);
+    isa_init_ioport(dev, 0x92);
 
     s->kbd = ps2_kbd_init(kbd_update_kbd_irq, s);
     s->mouse = ps2_mouse_init(kbd_update_aux_irq, s);
diff --git a/hw/sb16.c b/hw/sb16.c
index 78590a7..c9d37ad 100644
--- a/hw/sb16.c
+++ b/hw/sb16.c
@@ -1368,16 +1368,20 @@ static int sb16_initfn (ISADevice *dev)
 
     for (i = 0; i < ARRAY_SIZE (dsp_write_ports); i++) {
         register_ioport_write (s->port + dsp_write_ports[i], 1, 1, dsp_write, s);
+        isa_init_ioport(dev, s->port + dsp_write_ports[i]);
     }
 
     for (i = 0; i < ARRAY_SIZE (dsp_read_ports); i++) {
         register_ioport_read (s->port + dsp_read_ports[i], 1, 1, dsp_read, s);
+        isa_init_ioport(dev, s->port + dsp_read_ports[i]);
     }
 
     register_ioport_write (s->port + 0x4, 1, 1, mixer_write_indexb, s);
     register_ioport_write (s->port + 0x4, 1, 2, mixer_write_indexw, s);
+    isa_init_ioport(dev, s->port + 0x4);
     register_ioport_read (s->port + 0x5, 1, 1, mixer_read, s);
     register_ioport_write (s->port + 0x5, 1, 1, mixer_write_datab, s);
+    isa_init_ioport(dev, s->port + 0x5);
 
     DMA_register_channel (s->hdma, SB_read_DMA, s);
     DMA_register_channel (s->dma, SB_read_DMA, s);
diff --git a/hw/serial.c b/hw/serial.c
index 9ebc452..20902ae 100644
--- a/hw/serial.c
+++ b/hw/serial.c
@@ -778,6 +778,7 @@ static int serial_isa_initfn(ISADevice *dev)
 
     register_ioport_write(isa->iobase, 8, 1, serial_ioport_write, s);
     register_ioport_read(isa->iobase, 8, 1, serial_ioport_read, s);
+    isa_init_ioport_range(dev, isa->iobase, 8);
     return 0;
 }
 
