machine: Improve error message when using default RAM backend id

For migration purposes, users might want to reuse the default RAM
backend id, but specify a different memory backend.

For example, to reuse "pc.ram" on q35, one has to set
    -machine q35,memory-backend=pc.ram
Only then, can a memory backend with the id "pc.ram" be created
manually.

Let's improve the error message by improving the hint. Use
error_append_hint() -- which in turn requires ERRP_GUARD().

Message-ID: <20230906120503.359863-12-david@redhat.com>
Suggested-by: ThinerLogoer <logoerthiner1@163.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
This commit is contained in:
David Hildenbrand 2023-09-06 14:05:03 +02:00
parent 6da4b1c25d
commit 41ddcd2308

View file

@ -1355,6 +1355,7 @@ out:
void machine_run_board_init(MachineState *machine, const char *mem_path, Error **errp)
{
ERRP_GUARD();
MachineClass *machine_class = MACHINE_GET_CLASS(machine);
ObjectClass *oc = object_class_by_name(machine->cpu_type);
CPUClass *cc;
@ -1383,9 +1384,13 @@ void machine_run_board_init(MachineState *machine, const char *mem_path, Error *
numa_uses_legacy_mem()) {
if (object_property_find(object_get_objects_root(),
machine_class->default_ram_id)) {
error_setg(errp, "object name '%s' is reserved for the default"
" RAM backend, it can't be used for any other purposes."
" Change the object's 'id' to something else",
error_setg(errp, "object's id '%s' is reserved for the default"
" RAM backend, it can't be used for any other purposes",
machine_class->default_ram_id);
error_append_hint(errp,
"Change the object's 'id' to something else or disable"
" automatic creation of the default RAM backend by setting"
" 'memory-backend=%s' with '-machine'.\n",
machine_class->default_ram_id);
return;
}