hw/acpi: Move QMP command to hw/core/

The QERR_ macros are leftovers from the days of "rich" error objects.
We've been trying to reduce their remaining use.

qmp_query_vm_generation_id() in stubs/vmgenid.c is the last user of
QERR_UNSUPPORTED outside qga/.  Unlike the stubs we just dropped, it
is actually reachable, namely when CONFIG_ACPI_VMGENID is off.  It
always fails like

    (qemu) info vm-generation-id
    Error: this feature or command is not currently supported

Turns out the real qmp_query_vm_generation_id() doesn't actually
depend on CONFIG_ACPI_VMGENID, and fails safely when it's off.  Move
it to hw/core/machine-qmp-cmds.c, and drop the stub.  The error
message becomes

    Error: VM Generation ID device not found

Feels like an improvement to me.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230207075115.1525-8-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>

MAINTAINERS

@@ -2273,7 +2273,6 @@ F: hw/acpi/vmgenid.c
 F: include/hw/acpi/vmgenid.h
 F: docs/specs/vmgenid.txt
 F: tests/qtest/vmgenid-test.c
-F: stubs/vmgenid.c
 
 LED
 M: Philippe Mathieu-Daudé <philmd@linaro.org>

hw/acpi/vmgenid.c

@@ -12,7 +12,6 @@
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
-#include "qapi/qapi-commands-machine.h"
 #include "qemu/module.h"
 #include "hw/acpi/acpi.h"
 #include "hw/acpi/aml-build.h"
@@ -244,20 +243,3 @@ static void vmgenid_register_types(void)
 }
 
 type_init(vmgenid_register_types)
-
-GuidInfo *qmp_query_vm_generation_id(Error **errp)
-{
-    GuidInfo *info;
-    VmGenIdState *vms;
-    Object *obj = find_vmgenid_dev();
-
-    if (!obj) {
-        error_setg(errp, "VM Generation ID device not found");
-        return NULL;
-    }
-    vms = VMGENID(obj);
-
-    info = g_malloc0(sizeof(*info));
-    info->guid = qemu_uuid_unparse_strdup(&vms->guid);
-    return info;
-}

hw/core/machine-qmp-cmds.c

@@ -8,6 +8,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "hw/acpi/vmgenid.h"
 #include "hw/boards.h"
 #include "hw/intc/intc.h"
 #include "hw/mem/memory-device.h"
@@ -383,3 +384,20 @@ HumanReadableText *qmp_x_query_irq(Error **errp)
 
     return human_readable_text_from_str(buf);
 }
+
+GuidInfo *qmp_query_vm_generation_id(Error **errp)
+{
+    GuidInfo *info;
+    VmGenIdState *vms;
+    Object *obj = find_vmgenid_dev();
+
+    if (!obj) {
+        error_setg(errp, "VM Generation ID device not found");
+        return NULL;
+    }
+    vms = VMGENID(obj);
+
+    info = g_malloc0(sizeof(*info));
+    info->guid = qemu_uuid_unparse_strdup(&vms->guid);
+    return info;
+}

stubs/meson.build

@@ -45,7 +45,6 @@ stub_ss.add(files('target-get-monitor-def.c'))
 stub_ss.add(files('target-monitor-defs.c'))
 stub_ss.add(files('trace-control.c'))
 stub_ss.add(files('uuid.c'))
-stub_ss.add(files('vmgenid.c'))
 stub_ss.add(files('vmstate.c'))
 stub_ss.add(files('vm-stop.c'))
 stub_ss.add(files('win32-kbd-hook.c'))

stubs/vmgenid.c

@@ -1,10 +0,0 @@
-#include "qemu/osdep.h"
-#include "qapi/error.h"
-#include "qapi/qapi-commands-machine.h"
-#include "qapi/qmp/qerror.h"
-
-GuidInfo *qmp_query_vm_generation_id(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-    return NULL;
-}