diff --git a/Makefile.target b/Makefile.target
index 3261383..0d5286e 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -197,6 +197,7 @@ obj-$(CONFIG_REALLY_VIRTFS) += 9pfs/virtio-9p-device.o
 obj-$(CONFIG_KVM) += kvm.o kvm-all.o
 obj-$(CONFIG_NO_KVM) += kvm-stub.o
 obj-y += memory.o
+obj-y += memory_mapping.o
 LIBS+=-lz
 
 QEMU_CFLAGS += $(VNC_TLS_CFLAGS)
diff --git a/memory_mapping.c b/memory_mapping.c
new file mode 100644
index 0000000..d83b7d7
--- /dev/null
+++ b/memory_mapping.c
@@ -0,0 +1,130 @@
+/*
+ * QEMU memory mapping
+ *
+ * Copyright Fujitsu, Corp. 2011
+ *
+ * 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 MemoryMapping *last_mapping;
+
+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, *p;
+
+    memory_mapping = g_malloc(sizeof(MemoryMapping));
+    memory_mapping->phys_addr = phys_addr;
+    memory_mapping->virt_addr = virt_addr;
+    memory_mapping->length = length;
+    last_mapping = memory_mapping;
+    list->num++;
+    QTAILQ_FOREACH(p, &list->head, next) {
+        if (p->phys_addr >= memory_mapping->phys_addr) {
+            QTAILQ_INSERT_BEFORE(p, memory_mapping, next);
+            return;
+        }
+    }
+    QTAILQ_INSERT_TAIL(&list->head, memory_mapping, next);
+    return;
+}
+
+void create_new_memory_mapping_head(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;
+    last_mapping = memory_mapping;
+    list->num++;
+    QTAILQ_INSERT_HEAD(&list->head, memory_mapping, next);
+    return;
+}
+
+void add_to_memory_mapping(MemoryMappingList *list,
+                           target_phys_addr_t phys_addr,
+                           target_phys_addr_t virt_addr,
+                           ram_addr_t length)
+{
+    MemoryMapping *memory_mapping;
+
+    if (QTAILQ_EMPTY(&list->head)) {
+        create_new_memory_mapping(list, phys_addr, virt_addr, length);
+        return;
+    }
+
+    if (last_mapping) {
+        if ((phys_addr == (last_mapping->phys_addr + last_mapping->length)) &&
+            (virt_addr == (last_mapping->virt_addr + last_mapping->length))) {
+            last_mapping->length += length;
+            return;
+        }
+    }
+
+    QTAILQ_FOREACH(memory_mapping, &list->head, next) {
+        last_mapping = memory_mapping;
+        if ((phys_addr == (last_mapping->phys_addr + last_mapping->length)) &&
+            (virt_addr == (last_mapping->virt_addr + last_mapping->length))) {
+            last_mapping->length += length;
+            return;
+        }
+
+        if (!(phys_addr >= (last_mapping->phys_addr)) ||
+            !(phys_addr < (last_mapping->phys_addr + last_mapping->length))) {
+            /* last_mapping does not contain this region */
+            continue;
+        }
+        if (!(virt_addr >= (last_mapping->virt_addr)) ||
+            !(virt_addr < (last_mapping->virt_addr + last_mapping->length))) {
+            /* last_mapping does not contain this region */
+            continue;
+        }
+        if ((virt_addr - last_mapping->virt_addr) !=
+            (phys_addr - last_mapping->phys_addr)) {
+            /*
+             * last_mapping contains this region, but we should create another
+             * mapping region.
+             */
+            break;
+        }
+
+        /* merge this region into last_mapping */
+        if ((virt_addr + length) >
+            (last_mapping->virt_addr + last_mapping->length)) {
+            last_mapping->length = virt_addr + length - last_mapping->virt_addr;
+        }
+        return;
+    }
+
+    /* this region can not be merged into any existed memory mapping. */
+    create_new_memory_mapping(list, phys_addr, virt_addr, length);
+    return;
+}
+
+void free_memory_mapping_list(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;
+}
diff --git a/memory_mapping.h b/memory_mapping.h
new file mode 100644
index 0000000..a4b1532
--- /dev/null
+++ b/memory_mapping.h
@@ -0,0 +1,38 @@
+#ifndef MEMORY_MAPPING_H
+#define MEMORY_MAPPING_H
+
+#include "qemu-queue.h"
+
+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;
+    QTAILQ_HEAD(, MemoryMapping) head;
+} MemoryMappingList;
+
+/*
+ * crash needs some memory mapping should be at the head of the list. It will
+ * cause the list is not sorted. So the caller must add the special memory
+ * mapping after adding all the normal memory mapping into list.
+ */
+void create_new_memory_mapping_head(MemoryMappingList *list,
+                                    target_phys_addr_t phys_addr,
+                                    target_phys_addr_t virt_addr,
+                                    ram_addr_t length);
+/*
+ * add or merge the memory region into the memory mapping's list. The list is
+ * sorted by phys_addr.
+ */
+void add_to_memory_mapping(MemoryMappingList *list,
+                           target_phys_addr_t phys_addr,
+                           target_phys_addr_t virt_addr,
+                           ram_addr_t length);
+
+void free_memory_mapping_list(MemoryMappingList *list);
+
+#endif
