diff --git a/Makefile.target b/Makefile.target
index 1582904..005fc49 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -192,6 +192,7 @@ obj-$(CONFIG_KVM) += kvm.o kvm-all.o
 obj-$(CONFIG_NO_KVM) += kvm-stub.o
 obj-$(CONFIG_VGA) += vga.o
 obj-y += memory.o savevm.o cputlb.o
+obj-y += memory_mapping.o
 LIBS+=-lz
 
 obj-i386-$(CONFIG_KVM) += hyperv.o
diff --git a/memory_mapping.c b/memory_mapping.c
new file mode 100644
index 0000000..718f271
--- /dev/null
+++ b/memory_mapping.c
@@ -0,0 +1,166 @@
+/*
+ * QEMU memory mapping
+ *
+ * Copyright Fujitsu, Corp. 2011, 2012
+ *
+ * Authors:
+ *     Wen Congyang <wency@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "cpu.h"
+#include "cpu-all.h"
+#include "memory_mapping.h"
+
+static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list,
+                                                   MemoryMapping *mapping)
+{
+    MemoryMapping *p;
+
+    QTAILQ_FOREACH(p, &list->head, next) {
+        if (p->phys_addr >= mapping->phys_addr) {
+            QTAILQ_INSERT_BEFORE(p, mapping, next);
+            return;
+        }
+    }
+    QTAILQ_INSERT_TAIL(&list->head, mapping, next);
+}
+
+static void create_new_memory_mapping(MemoryMappingList *list,
+                                      target_phys_addr_t phys_addr,
+                                      target_phys_addr_t virt_addr,
+                                      ram_addr_t length)
+{
+    MemoryMapping *memory_mapping;
+
+    memory_mapping = g_malloc(sizeof(MemoryMapping));
+    memory_mapping->phys_addr = phys_addr;
+    memory_mapping->virt_addr = virt_addr;
+    memory_mapping->length = length;
+    list->last_mapping = memory_mapping;
+    list->num++;
+    memory_mapping_list_add_mapping_sorted(list, memory_mapping);
+}
+
+static inline bool mapping_contiguous(MemoryMapping *map,
+                                      target_phys_addr_t phys_addr,
+                                      target_phys_addr_t virt_addr)
+{
+    return phys_addr == map->phys_addr + map->length &&
+           virt_addr == map->virt_addr + map->length;
+}
+
+/*
+ * [map->phys_addr, map->phys_addr + map->length) and
+ * [phys_addr, phys_addr + length) have intersection?
+ */
+static inline bool mapping_have_same_region(MemoryMapping *map,
+                                            target_phys_addr_t phys_addr,
+                                            ram_addr_t length)
+{
+    return !(phys_addr + length < map->phys_addr ||
+             phys_addr >= map->phys_addr + map->length);
+}
+
+/*
+ * [map->phys_addr, map->phys_addr + map->length) and
+ * [phys_addr, phys_addr + length) have intersection. The virtual address in the
+ * intersection are the same?
+ */
+static inline bool mapping_conflict(MemoryMapping *map,
+                                    target_phys_addr_t phys_addr,
+                                    target_phys_addr_t virt_addr)
+{
+    return virt_addr - map->virt_addr != phys_addr - map->phys_addr;
+}
+
+/*
+ * [map->virt_addr, map->virt_addr + map->length) and
+ * [virt_addr, virt_addr + length) have intersection. And the physical address
+ * in the intersection are the same.
+ */
+static inline void mapping_merge(MemoryMapping *map,
+                                 target_phys_addr_t virt_addr,
+                                 ram_addr_t length)
+{
+    if (virt_addr < map->virt_addr) {
+        map->length += map->virt_addr - virt_addr;
+        map->virt_addr = virt_addr;
+    }
+
+    if ((virt_addr + length) >
+        (map->virt_addr + map->length)) {
+        map->length = virt_addr + length - map->virt_addr;
+    }
+}
+
+void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,
+                                          target_phys_addr_t phys_addr,
+                                          target_phys_addr_t virt_addr,
+                                          ram_addr_t length)
+{
+    MemoryMapping *memory_mapping, *last_mapping;
+
+    if (QTAILQ_EMPTY(&list->head)) {
+        create_new_memory_mapping(list, phys_addr, virt_addr, length);
+        return;
+    }
+
+    last_mapping = list->last_mapping;
+    if (last_mapping) {
+        if (mapping_contiguous(last_mapping, phys_addr, virt_addr)) {
+            last_mapping->length += length;
+            return;
+        }
+    }
+
+    QTAILQ_FOREACH(memory_mapping, &list->head, next) {
+        if (mapping_contiguous(memory_mapping, phys_addr, virt_addr)) {
+            memory_mapping->length += length;
+            list->last_mapping = memory_mapping;
+            return;
+        }
+
+        if (phys_addr + length < memory_mapping->phys_addr) {
+            /* create a new region before memory_mapping */
+            break;
+        }
+
+        if (mapping_have_same_region(memory_mapping, phys_addr, length)) {
+            if (mapping_conflict(memory_mapping, phys_addr, virt_addr)) {
+                continue;
+            }
+
+            /* merge this region into memory_mapping */
+            mapping_merge(memory_mapping, virt_addr, length);
+            list->last_mapping = memory_mapping;
+            return;
+        }
+    }
+
+    /* this region can not be merged into any existed memory mapping. */
+    create_new_memory_mapping(list, phys_addr, virt_addr, length);
+}
+
+void memory_mapping_list_free(MemoryMappingList *list)
+{
+    MemoryMapping *p, *q;
+
+    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
+        QTAILQ_REMOVE(&list->head, p, next);
+        g_free(p);
+    }
+
+    list->num = 0;
+    list->last_mapping = NULL;
+}
+
+void memory_mapping_list_init(MemoryMappingList *list)
+{
+    list->num = 0;
+    list->last_mapping = NULL;
+    QTAILQ_INIT(&list->head);
+}
diff --git a/memory_mapping.h b/memory_mapping.h
new file mode 100644
index 0000000..836b047
--- /dev/null
+++ b/memory_mapping.h
@@ -0,0 +1,47 @@
+/*
+ * QEMU memory mapping
+ *
+ * Copyright Fujitsu, Corp. 2011, 2012
+ *
+ * Authors:
+ *     Wen Congyang <wency@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef MEMORY_MAPPING_H
+#define MEMORY_MAPPING_H
+
+#include "qemu-queue.h"
+
+/* The physical and virtual address in the memory mapping are contiguous. */
+typedef struct MemoryMapping {
+    target_phys_addr_t phys_addr;
+    target_ulong virt_addr;
+    ram_addr_t length;
+    QTAILQ_ENTRY(MemoryMapping) next;
+} MemoryMapping;
+
+typedef struct MemoryMappingList {
+    unsigned int num;
+    MemoryMapping *last_mapping;
+    QTAILQ_HEAD(, MemoryMapping) head;
+} MemoryMappingList;
+
+/*
+ * add or merge the memory region [phys_addr, phys_addr + length) into the
+ * memory mapping's list. The region's virtual address starts with virt_addr,
+ * and is contiguous. The list is sorted by phys_addr.
+ */
+void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,
+                                          target_phys_addr_t phys_addr,
+                                          target_phys_addr_t virt_addr,
+                                          ram_addr_t length);
+
+void memory_mapping_list_free(MemoryMappingList *list);
+
+void memory_mapping_list_init(MemoryMappingList *list);
+
+#endif
