[PATCH v3 10/10] migration/dirtyrate: Implement qmp_cal_dirty_rate()/qmp_get_dirty_rate() function

[Chuan Zheng <zhengchuan@huawei.com>]

Implement qmp_cal_dirty_rate()/qmp_get_dirty_rate() function which could be called

Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
---
 migration/dirtyrate.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++
 qapi/migration.json   | 42 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 98 insertions(+)

diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
index 041d0c6..0e8c9c5 100644
--- a/migration/dirtyrate.c
+++ b/migration/dirtyrate.c
@@ -67,6 +67,39 @@ static int dirty_rate_set_state(int new_state)
     return 0;
 }
 
+static struct DirtyRateInfo *query_dirty_rate_info(void)
+{
+    int64_t dirty_rate = dirty_stat.dirty_rate;
+    struct DirtyRateInfo *info = g_malloc0(sizeof(DirtyRateInfo));
+
+    switch (CalculatingState) {
+    case CAL_DIRTY_RATE_INIT:
+        info->dirty_rate = -1;
+        info->status = g_strdup("Not start measuring");
+        break;
+    case CAL_DIRTY_RATE_ACTIVE:
+        info->dirty_rate = -1;
+        info->status = g_strdup("Still measuring");
+        break;
+    case CAL_DIRTY_RATE_END:
+        info->dirty_rate = dirty_rate;
+        info->status = g_strdup("Measured");
+        break;
+    default:
+        info->dirty_rate = -1;
+        info->status = g_strdup("Unknown status");
+        break;
+    }
+
+    /*
+     * Only support query once for each calculation,
+     * reset as CAL_DIRTY_RATE_INIT after query
+     */
+    (void)dirty_rate_set_state(CAL_DIRTY_RATE_INIT);
+
+    return info;
+}
+
 static void reset_dirtyrate_stat(void)
 {
     dirty_stat.total_dirty_samples = 0;
@@ -403,3 +436,26 @@ void *get_dirtyrate_thread(void *arg)
 
     return NULL;
 }
+
+void qmp_calc_dirty_rate(int64_t calc_time, Error **errp)
+{
+    static struct DirtyRateConfig config;
+    QemuThread thread;
+
+    /*
+     * We don't begin calculating thread only when it's in calculating status.
+     */
+    if (CalculatingState == CAL_DIRTY_RATE_ACTIVE) {
+        return;
+    }
+
+    config.sample_period_seconds = get_sample_page_period(calc_time);
+    config.sample_pages_per_gigabytes = DIRTYRATE_DEFAULT_SAMPLE_PAGES;
+    qemu_thread_create(&thread, "get_dirtyrate", get_dirtyrate_thread,
+                       (void *)&config, QEMU_THREAD_DETACHED);
+}
+
+struct DirtyRateInfo *qmp_query_dirty_rate(Error **errp)
+{
+    return query_dirty_rate_info();
+}
diff --git a/qapi/migration.json b/qapi/migration.json
index d500055..ccc7a4e 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1621,3 +1621,45 @@
 ##
 { 'event': 'UNPLUG_PRIMARY',
   'data': { 'device-id': 'str' } }
+
+##
+# @DirtyRateInfo:
+#
+# Information about current dirty page rate of vm.
+#
+# @dirty-rate: @dirtyrate describing the dirty page rate of vm
+#          in units of MB/s.
+#          If this field return '-1', it means querying is not
+#          start or not complete.
+#
+# @status: @status containing dirtyrate query status includes
+#       status with 'not start measuring' or
+#       'Still measuring' or 'measured'(since 5.2)
+##
+{ 'struct': 'DirtyRateInfo',
+  'data': {'dirty-rate': 'int64',
+           'status': 'str'} }
+
+##
+# @calc-dirty-rate:
+#
+# start calculating dirty page rate for vm
+#
+# @calc-time: time in units of second for sample dirty pages
+#
+# Since: 5.2
+#
+# Example:
+#   {"command": "cal-dirty-rate", "data": {"calc-time": 1} }
+#
+##
+{ 'command': 'calc-dirty-rate', 'data': {'calc-time': 'int64'} }
+
+##
+# @query-dirty-rate:
+#
+# query dirty page rate in units of MB/s for vm
+#
+# Since: 5.2
+##
+{ 'command': 'query-dirty-rate', 'returns': 'DirtyRateInfo' }
-- 
1.8.3.1