qemu_agent: Add qemuAgentGetLoadAvg()

With qemu guest agent 9.3 we are able to get the load averages with a
new command.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>

src/qemu/qemu_agent.c

@@ -2568,3 +2568,49 @@ int qemuAgentGetDisks(qemuAgent *agent,
     g_free(*disks);
     return -1;
 }
+
+
+int
+qemuAgentGetLoadAvg(qemuAgent *agent,
+                    double *load1m,
+                    double *load5m,
+                    double *load15m,
+                    bool report_unsupported)
+{
+    g_autoptr(virJSONValue) cmd = NULL;
+    g_autoptr(virJSONValue) reply = NULL;
+    virJSONValue *data = NULL;
+    int rc;
+
+    if (!(cmd = qemuAgentMakeCommand("guest-get-load", NULL)))
+        return -1;
+
+    if ((rc = qemuAgentCommandFull(agent, cmd, &reply, agent->timeout,
+                                   report_unsupported)) < 0)
+        return rc;
+
+    if (!(data = virJSONValueObjectGetObject(reply, "return"))) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("qemu agent didn't return an array of loads"));
+        return -1;
+    }
+
+#define GET_NUMBER_PARAM(param_) \
+    do { \
+        if (param_ && \
+            virJSONValueObjectGetNumberDouble(data, #param_, param_) < 0) { \
+            virReportError(VIR_ERR_INTERNAL_ERROR, \
+                           _("parameter '%1$s' is missing in reply of guest-get-load"), \
+                           #param_); \
+            return -1; \
+        } \
+    } while (0)
+
+    GET_NUMBER_PARAM(load1m);
+    GET_NUMBER_PARAM(load5m);
+    GET_NUMBER_PARAM(load15m);
+
+#undef GET_NUMBER_PARAM
+
+    return 0;
+}

src/qemu/qemu_agent.h

@@ -195,3 +195,9 @@ int qemuAgentSSHRemoveAuthorizedKeys(qemuAgent *agent,
 int qemuAgentGetDisks(qemuAgent *mon,
                       qemuAgentDiskInfo ***disks,
                       bool report_unsupported);
+
+int qemuAgentGetLoadAvg(qemuAgent *agent,
+                        double *load1m,
+                        double *load5m,
+                        double *load15m,
+                        bool report_unsupported);

tests/qemuagenttest.c

@@ -1356,6 +1356,58 @@ testQemuAgentTimezone(const void *data)
     virTypedParamsFree(params, nparams);
     return ret;
 }
+
+
+static const char testQemuAgentGetLoadAvgResponse[] =
+    "{"
+    "  \"return\": {"
+    "    \"load15m\": 0.03564453125,"
+    "    \"load5m\": 0.064453125,"
+    "    \"load1m\": 0.00390625"
+    "  }"
+    "}";
+
+static int
+testQemuAgentGetLoadAvg(const void *data)
+{
+    virDomainXMLOption *xmlopt = (virDomainXMLOption *)data;
+    g_autoptr(qemuMonitorTest) test = qemuMonitorTestNewAgent(xmlopt);
+    double load1m = 0;
+    double load5m = 0;
+    double load15m = 0;
+
+    if (!test)
+        return -1;
+
+    if (qemuMonitorTestAddAgentSyncResponse(test) < 0)
+        return -1;
+
+    if (qemuMonitorTestAddItem(test, "guest-get-load",
+                               testQemuAgentGetLoadAvgResponse) < 0)
+        return -1;
+
+    if (qemuAgentGetLoadAvg(qemuMonitorTestGetAgent(test),
+                            &load1m, &load5m, &load15m, true) < 0)
+        return -1;
+
+#define VALIDATE_LOAD(value_, expected_) \
+    do { \
+        if (value_ != expected_) { \
+            virReportError(VIR_ERR_INTERNAL_ERROR, \
+                           "Expected " #value_ " '%.11f', got '%.11f'", \
+                           expected_, value_); \
+            return -1; \
+        } \
+    } while (0)
+
+    VALIDATE_LOAD(load1m, 0.00390625);
+    VALIDATE_LOAD(load5m, 0.064453125);
+    VALIDATE_LOAD(load15m, 0.03564453125);
+
+    return 0;
+}
+
+
 static int
 mymain(void)
 {
@@ -1392,6 +1444,7 @@ mymain(void)
     DO_TEST(Timezone);
     DO_TEST(SSHKeys);
     DO_TEST(GetDisks);
+    DO_TEST(GetLoadAvg);
 
     DO_TEST(Timeout); /* Timeout should always be called last */