diff --git a/migration-dirtyrate-Compare-page-hash-results-for-re.patch b/migration-dirtyrate-Compare-page-hash-results-for-re.patch
new file mode 100644
index 0000000..b9277d5
--- /dev/null
+++ b/migration-dirtyrate-Compare-page-hash-results-for-re.patch
@@ -0,0 +1,95 @@
+From 949612c5bbc5414970aed7d7ec9390a058ee2246 Mon Sep 17 00:00:00 2001
+From: Chuan Zheng <zhengchuan@huawei.com>
+Date: Wed, 16 Sep 2020 14:22:02 +0800
+Subject: [PATCH] migration/dirtyrate: Compare page hash results for recorded
+ sampled page
+
+Compare page hash results for recorded sampled page.
+
+Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
+Signed-off-by: YanYing Zhuang <ann.zhuangyanying@huawei.com>
+Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
+Reviewed-by: Li Qiang <liq3ea@gmail.com>
+Message-Id: <1600237327-33618-8-git-send-email-zhengchuan@huawei.com>
+Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
+---
+ migration/dirtyrate.c | 63 +++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 63 insertions(+)
+
+diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
+index f93601f8ab..0412f825dc 100644
+--- a/migration/dirtyrate.c
++++ b/migration/dirtyrate.c
+@@ -177,6 +177,69 @@ out:
+     return ret;
+ }
+ 
++static void calc_page_dirty_rate(struct RamblockDirtyInfo *info)
++{
++    uint32_t crc;
++    int i;
++
++    for (i = 0; i < info->sample_pages_count; i++) {
++        crc = get_ramblock_vfn_hash(info, info->sample_page_vfn[i]);
++        if (crc != info->hash_result[i]) {
++            info->sample_dirty_count++;
++        }
++    }
++}
++
++static struct RamblockDirtyInfo *
++find_block_matched(RAMBlock *block, int count,
++                  struct RamblockDirtyInfo *infos)
++{
++    int i;
++    struct RamblockDirtyInfo *matched;
++
++    for (i = 0; i < count; i++) {
++        if (!strcmp(infos[i].idstr, qemu_ram_get_idstr(block))) {
++            break;
++        }
++    }
++
++    if (i == count) {
++        return NULL;
++    }
++
++    if (infos[i].ramblock_addr != qemu_ram_get_host_addr(block) ||
++        infos[i].ramblock_pages !=
++            (qemu_ram_get_used_length(block) >> TARGET_PAGE_BITS)) {
++        return NULL;
++    }
++
++    matched = &infos[i];
++
++    return matched;
++}
++
++static bool compare_page_hash_info(struct RamblockDirtyInfo *info,
++                                  int block_count)
++{
++    struct RamblockDirtyInfo *block_dinfo = NULL;
++    RAMBlock *block = NULL;
++
++    RAMBLOCK_FOREACH_MIGRATABLE(block) {
++        block_dinfo = find_block_matched(block, block_count, info);
++        if (block_dinfo == NULL) {
++            continue;
++        }
++        calc_page_dirty_rate(block_dinfo);
++        update_dirtyrate_stat(block_dinfo);
++    }
++
++    if (DirtyStat.total_sample_count == 0) {
++        return false;
++    }
++
++    return true;
++}
++
+ static void calculate_dirtyrate(struct DirtyRateConfig config)
+ {
+     /* todo */
+-- 
+2.27.0
+