[PATCH v6 4/5] migration/dirtyrate: Implement qemuMonitorQueryDirtyRate

[Hao Wang]

Implement qemuMonitorQueryDirtyRate which query domain's memory
dirty rate calling qmp "query-dirty-rate".

Signed-off-by: Hao Wang <wanghao232 at huawei.com>
---
 src/qemu/qemu_monitor.c      | 12 +++++++
 src/qemu/qemu_monitor.h      | 14 ++++++++
 src/qemu/qemu_monitor_json.c | 66 ++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_monitor_json.h |  4 +++
 4 files changed, 96 insertions(+)

diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 05c57f5f1d..dcc529b405 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -4754,3 +4754,15 @@ qemuMonitorStartDirtyRateCalc(qemuMonitorPtr mon,
 
     return qemuMonitorJSONStartDirtyRateCalc(mon, seconds);
 }
+
+
+int
+qemuMonitorQueryDirtyRate(qemuMonitorPtr mon,
+                          qemuMonitorDirtyRateInfoPtr info)
+{
+    VIR_DEBUG("info=%p", info);
+
+    QEMU_CHECK_MONITOR(mon);
+
+    return qemuMonitorJSONQueryDirtyRate(mon, info);
+}
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 94813906b4..9958657c2c 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -1530,3 +1530,17 @@ qemuMonitorTransactionBackup(virJSONValuePtr actions,
 int
 qemuMonitorStartDirtyRateCalc(qemuMonitorPtr mon,
                               int seconds);
+
+typedef struct _qemuMonitorDirtyRateInfo qemuMonitorDirtyRateInfo;
+typedef qemuMonitorDirtyRateInfo *qemuMonitorDirtyRateInfoPtr;
+
+struct _qemuMonitorDirtyRateInfo {
+    char *status;           /* the status of last dirtyrate calculation */
+    long long dirtyRate;    /* the dirtyrate in MiB/s */
+    long long startTime;    /* the start time of dirtyrate calculation */
+    int calcTime;           /* the period of dirtyrate calculation */
+};
+
+int
+qemuMonitorQueryDirtyRate(qemuMonitorPtr mon,
+                          qemuMonitorDirtyRateInfoPtr info);
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index e6c127ab61..409fb817bf 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -9505,3 +9505,69 @@ qemuMonitorJSONStartDirtyRateCalc(qemuMonitorPtr mon,
 
     return 0;
 }
+
+
+static int
+qemuMonitorJSONExtractDirtyRateInfo(virJSONValuePtr data,
+                                    qemuMonitorDirtyRateInfoPtr info)
+{
+    const char *status;
+
+    if (!(status = virJSONValueObjectGetString(data, "status"))) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("query-dirty-rate reply was missing 'status' data"));
+        return -1;
+    }
+    info->status = g_strdup(status);
+
+    /* `query-dirty-rate` replies `dirty-rate` data only if the status of the latest
+     * calculation is `measured`.
+     */
+    if (STREQ(info->status, "measured") &&
+        (virJSONValueObjectGetNumberLong(data, "dirty-rate", &info->dirtyRate) < 0)) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("query-dirty-rate reply was missing 'dirty-rate' data"));
+        return -1;
+    }
+
+    if (virJSONValueObjectGetNumberLong(data, "start-time", &info->startTime) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("query-dirty-rate reply was missing 'start-time' data"));
+        return -1;
+    }
+
+    if (virJSONValueObjectGetNumberInt(data, "calc-time", &info->calcTime) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("query-dirty-rate reply was missing 'calc-time' data"));
+        return -1;
+    }
+
+    return 0;
+}
+
+
+int
+qemuMonitorJSONQueryDirtyRate(qemuMonitorPtr mon,
+                              qemuMonitorDirtyRateInfoPtr info)
+{
+    g_autoptr(virJSONValue) cmd = NULL;
+    g_autoptr(virJSONValue) reply = NULL;
+    virJSONValuePtr data = NULL;
+
+    if (!(cmd = qemuMonitorJSONMakeCommand("query-dirty-rate", NULL)))
+        return -1;
+
+    if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
+        return -1;
+
+    if (qemuMonitorJSONCheckError(cmd, reply) < 0)
+        return -1;
+
+    if (!(data = virJSONValueObjectGetObject(reply, "return"))) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("query-dirty-rate reply was missing 'return' data"));
+        return -1;
+    }
+
+    return qemuMonitorJSONExtractDirtyRateInfo(data, info);
+}
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index 32782cf681..8d4232f67b 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -715,3 +715,7 @@ qemuMonitorJSONGetCPUMigratable(qemuMonitorPtr mon,
 int
 qemuMonitorJSONStartDirtyRateCalc(qemuMonitorPtr mon,
                                   int seconds);
+
+int
+qemuMonitorJSONQueryDirtyRate(qemuMonitorPtr mon,
+                              qemuMonitorDirtyRateInfoPtr info);
-- 
2.23.0