target: Improve error reporting for CpuModelInfo member @props

query-cpu-model-comparison, query-cpu-model-baseline, and
query-cpu-model-expansion take CpuModelInfo arguments.  Errors in
@props members of these arguments are reported for 'props', without
further context.  For instance, s390x rejects

    {"execute": "query-cpu-model-comparison", "arguments": {"modela": {"name": "z13", "props": {}}, "modelb": {"name": "z14", "props": []}}}

with

    {"error": {"class": "GenericError", "desc": "Invalid parameter type for 'props', expected: object"}}

This is unusual; the common QAPI unmarshaling machinery would complain
about 'modelb.props'.  Our hand-written code to visit the @props
member neglects to provide the context.

Tweak it so it provides it.  The command above now fails with

    {"error": {"class": "GenericError", "desc": "Invalid parameter type for 'modelb.props', expected: dict"}}

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240305145919.2186971-4-armbru@redhat.com>
Acked-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/target/riscv/riscv-qmp-cmds.c b/target/riscv/riscv-qmp-cmds.c
index d0360c0528..d363dc318d 100644
--- a/target/riscv/riscv-qmp-cmds.c
+++ b/target/riscv/riscv-qmp-cmds.c
@@ -128,6 +128,7 @@ static void riscv_obj_add_profiles_qdict(Object *obj, QDict *qdict_out)
 }
 
 static void riscv_cpuobj_validate_qdict_in(Object *obj, QObject *props,
+                                           const char *props_arg_name,
                                            Error **errp)
 {
     const QDict *qdict_in;
@@ -136,7 +137,7 @@ static void riscv_cpuobj_validate_qdict_in(Object *obj, QObject *props,
     Error *local_err = NULL;
 
     visitor = qobject_input_visitor_new(props);
-    if (!visit_start_struct(visitor, "props", NULL, 0, &local_err)) {
+    if (!visit_start_struct(visitor, props_arg_name, NULL, 0, &local_err)) {
         goto err;
     }
 
@@ -197,7 +198,8 @@ CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
     }
 
     if (model->props) {
-        riscv_cpuobj_validate_qdict_in(obj, model->props, &local_err);
+        riscv_cpuobj_validate_qdict_in(obj, model->props, "model.props",
+                                       &local_err);
         if (local_err) {
             error_propagate(errp, local_err);
             object_unref(obj);