qemuAgentCommand: Wire up suppressing of error reporting for unsupported commands

In some cases we don't want to log errors if an agent command is
unsupported. Wire it up into qemuAgentCheckError via qemuAgentCommandFull
and provide a thin wrapper (qemuAgentCommand) to prevent having to fix
all callers.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_agent.c

@@ -1051,7 +1051,8 @@ qemuAgentCommandName(virJSONValuePtr cmd)
 
 static int
 qemuAgentCheckError(virJSONValuePtr cmd,
-                    virJSONValuePtr reply)
+                    virJSONValuePtr reply,
+                    bool report_unsupported)
 {
     if (virJSONValueObjectHasKey(reply, "error")) {
         virJSONValuePtr error = virJSONValueObjectGet(reply, "error");
@@ -1063,11 +1064,21 @@ qemuAgentCheckError(virJSONValuePtr cmd,
                   NULLSTR(cmdstr), NULLSTR(replystr));
 
         /* Only send the user the command name + friendly error */
-        if (!error)
+        if (!error) {
             virReportError(VIR_ERR_INTERNAL_ERROR,
                            _("unable to execute QEMU agent command '%s'"),
                            qemuAgentCommandName(cmd));
-        else
+            return -1;
+        }
+
+        if (!report_unsupported) {
+            const char *klass = virJSONValueObjectGetString(error, "class");
+
+            if (STREQ_NULLABLE(klass, "CommandNotFound") ||
+                STREQ_NULLABLE(klass, "CommandDisabled"))
+                return -2;
+        }
+
         virReportError(VIR_ERR_INTERNAL_ERROR,
                        _("unable to execute QEMU agent command '%s': %s"),
                        qemuAgentCommandName(cmd),
@@ -1089,10 +1100,11 @@ qemuAgentCheckError(virJSONValuePtr cmd,
 }
 
 static int
-qemuAgentCommand(qemuAgentPtr agent,
+qemuAgentCommandFull(qemuAgentPtr agent,
                      virJSONValuePtr cmd,
                      virJSONValuePtr *reply,
-                 int seconds)
+                     int seconds,
+                     bool report_unsupported)
 {
     int ret = -1;
     qemuAgentMessage msg;
@@ -1143,7 +1155,7 @@ qemuAgentCommand(qemuAgentPtr agent,
     }
 
     *reply = msg.rxObject;
-    ret = qemuAgentCheckError(cmd, *reply);
+    ret = qemuAgentCheckError(cmd, *reply, report_unsupported);
 
  cleanup:
     VIR_FREE(cmdstr);
@@ -1153,6 +1165,15 @@ qemuAgentCommand(qemuAgentPtr agent,
     return ret;
 }
 
+static int
+qemuAgentCommand(qemuAgentPtr agent,
+                 virJSONValuePtr cmd,
+                 virJSONValuePtr *reply,
+                 int seconds)
+{
+    return qemuAgentCommandFull(agent, cmd, reply, seconds, true);
+}
+
 static virJSONValuePtr G_GNUC_NULL_TERMINATED
 qemuAgentMakeCommand(const char *cmdname,
                      ...)