diff --git a/Makefile.objs b/Makefile.objs
index 8d23fbb..86ab37b 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -82,7 +82,7 @@ common-obj-$(CONFIG_WIN32) += os-win32.o
 common-obj-$(CONFIG_POSIX) += os-posix.o
 
 common-obj-y += tcg-runtime.o host-utils.o
-common-obj-y += irq.o ioport.o input.o
+common-obj-y += irq.o input.o
 common-obj-$(CONFIG_PTIMER) += ptimer.o
 common-obj-$(CONFIG_MAX7310) += max7310.o
 common-obj-$(CONFIG_WM8750) += wm8750.o
diff --git a/Makefile.target b/Makefile.target
index 88d2f1f..c1529b3 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -183,7 +183,7 @@ endif #CONFIG_BSD_USER
 # System emulator target
 ifdef CONFIG_SOFTMMU
 
-obj-y = arch_init.o cpus.o monitor.o machine.o gdbstub.o balloon.o
+obj-y = arch_init.o cpus.o monitor.o machine.o gdbstub.o balloon.o ioport.o
 # virtio has to be here due to weird dependency between PCI and virtio-net.
 # need to fix this properly
 obj-$(CONFIG_NO_PCI) += pci-stub.o
diff --git a/ioport.c b/ioport.c
index a32483b..36fa3a4 100644
--- a/ioport.c
+++ b/ioport.c
@@ -27,6 +27,7 @@
 
 #include "ioport.h"
 #include "trace.h"
+#include "memory.h"
 
 /***********************************************************/
 /* IO Port */
@@ -313,3 +314,110 @@ uint32_t cpu_inl(pio_addr_t addr)
     LOG_IOPORT("inl : %04"FMT_pioaddr" %08"PRIx32"\n", addr, val);
     return val;
 }
+
+void portio_list_init(PortioList *piolist,
+                      const MemoryRegionPortio *callbacks,
+                      void *opaque, const char *name)
+{
+    unsigned n = 0;
+
+    while (callbacks[n].size) {
+        ++n;
+    }
+
+    piolist->ports = callbacks;
+    piolist->nr = 0;
+    piolist->regions = g_new0(MemoryRegion *, n);
+    piolist->address_space = NULL;
+    piolist->opaque = opaque;
+    piolist->name = name;
+}
+
+void portio_list_destroy(PortioList *piolist)
+{
+    g_free(piolist->regions);
+}
+
+static void portio_list_add_1(PortioList *piolist,
+                              const MemoryRegionPortio *pio_init,
+                              unsigned count, unsigned start,
+                              unsigned off_low, unsigned off_high)
+{
+    MemoryRegionPortio *pio;
+    MemoryRegionOps *ops;
+    MemoryRegion *region;
+    unsigned i;
+
+    /* Copy the sub-list and null-terminate it.  */
+    pio = g_new(MemoryRegionPortio, count + 1);
+    memcpy(pio, pio_init, sizeof(MemoryRegionPortio) * count);
+    memset(pio + count, 0, sizeof(MemoryRegionPortio));
+
+    /* Adjust the offsets to all be zero-based for the region.  */
+    for (i = 0; i < count; ++i) {
+        pio[i].offset -= off_low;
+    }
+
+    ops = g_new0(MemoryRegionOps, 1);
+    ops->old_portio = pio;
+
+    region = g_new(MemoryRegion, 1);
+    memory_region_init_io(region, ops, piolist->opaque, piolist->name,
+                          off_high - off_low);
+    memory_region_set_offset(region, start + off_low);
+    memory_region_add_subregion(piolist->address_space,
+                                start + off_low, region);
+    piolist->regions[piolist->nr++] = region;
+}
+
+void portio_list_add(PortioList *piolist,
+                     MemoryRegion *address_space,
+                     uint32_t start)
+{
+    const MemoryRegionPortio *pio, *pio_start = piolist->ports;
+    unsigned int off_low, off_high, off_last, count;
+
+    piolist->address_space = address_space;
+
+    /* Handle the first entry specially.  */
+    off_last = off_low = pio_start->offset;
+    off_high = off_low + pio_start->len;
+    count = 1;
+
+    for (pio = pio_start + 1; pio->size != 0; pio++, count++) {
+        /* All entries must be sorted by offset.  */
+        assert(pio->offset >= off_last);
+        off_last = pio->offset;
+
+        /* If we see a hole, break the region.  */
+        if (off_last > off_high) {
+            portio_list_add_1(piolist, pio_start, count, start, off_low,
+                              off_high);
+            /* ... and start collecting anew.  */
+            pio_start = pio;
+            off_low = off_last;
+            off_high = off_low + pio->len;
+            count = 0;
+        } else if (off_last + pio->len > off_high) {
+            off_high = off_last + pio->len;
+        }
+    }
+
+    /* There will always be an open sub-list.  */
+    portio_list_add_1(piolist, pio_start, count, start, off_low, off_high);
+}
+
+void portio_list_del(PortioList *piolist)
+{
+    MemoryRegion *mr;
+    unsigned i;
+
+    for (i = 0; i < piolist->nr; ++i) {
+        mr = piolist->regions[i];
+        memory_region_del_subregion(piolist->address_space, mr);
+        memory_region_destroy(mr);
+        g_free((MemoryRegionOps *)mr->ops);
+        g_free(mr);
+        piolist->regions[i] = NULL;
+    }
+}
diff --git a/ioport.h b/ioport.h
index 82ffd9d..968cc23 100644
--- a/ioport.h
+++ b/ioport.h
@@ -52,4 +52,25 @@ uint8_t cpu_inb(pio_addr_t addr);
 uint16_t cpu_inw(pio_addr_t addr);
 uint32_t cpu_inl(pio_addr_t addr);
 
+typedef struct MemoryRegion MemoryRegion;
+typedef struct MemoryRegionPortio MemoryRegionPortio;
+
+typedef struct PortioList {
+    const MemoryRegionPortio *ports;
+    MemoryRegion *address_space;
+    unsigned nr;
+    MemoryRegion **regions;
+    void *opaque;
+    const char *name;
+} PortioList;
+
+void portio_list_init(PortioList *piolist,
+                      const MemoryRegionPortio *callbacks,
+                      void *opaque, const char *name);
+void portio_list_destroy(PortioList *piolist);
+void portio_list_add(PortioList *piolist,
+                     MemoryRegion *address_space,
+                     uint32_t addr);
+void portio_list_del(PortioList *piolist);
+
 #endif /* IOPORT_H */
diff --git a/memory.c b/memory.c
index 71e769e..528e5fb 100644
--- a/memory.c
+++ b/memory.c
@@ -403,12 +403,12 @@ static void memory_region_iorange_read(IORange *iorange,
 
         *data = ((uint64_t)1 << (width * 8)) - 1;
         if (mrp) {
-            *data = mrp->read(mr->opaque, offset);
+            *data = mrp->read(mr->opaque, offset + mr->offset);
         }
         return;
     }
     *data = 0;
-    access_with_adjusted_size(offset, data, width,
+    access_with_adjusted_size(offset + mr->offset, data, width,
                               mr->ops->impl.min_access_size,
                               mr->ops->impl.max_access_size,
                               memory_region_read_accessor, mr);
@@ -425,11 +425,11 @@ static void memory_region_iorange_write(IORange *iorange,
         const MemoryRegionPortio *mrp = find_portio(mr, offset, width, true);
 
         if (mrp) {
-            mrp->write(mr->opaque, offset, data);
+            mrp->write(mr->opaque, offset + mr->offset, data);
         }
         return;
     }
-    access_with_adjusted_size(offset, &data, width,
+    access_with_adjusted_size(offset + mr->offset, &data, width,
                               mr->ops->impl.min_access_size,
                               mr->ops->impl.max_access_size,
                               memory_region_write_accessor, mr);
