[Qemu-devel] [PATCH v3] qom: Make all interface types abstract

[Eduardo Habkost]

"qom-list-types abstract=false" currently returns all interface
types, as if they were not abstract. Fix this by making sure all
interface types are abstract.

All interface types have instance_size == 0, so we can use
it to set abstract=true on type_initialize().

Signed-off-by: Eduardo Habkost <address@hidden>
---
Changes v1 -> v2:
* Use old-fashioned if statement instead of "|=" on bool field
  Suggested-by: Andreas Färber <address@hidden>
* Keep "device/introspect" path prefix on unit test
  * Suggested-by: Andreas Färber <address@hidden>

Changes v2 -> v3:
* Instead of making interfaces implicitly abstract,
  set abstract=true explicitly for all of them and replace
  type_initialize() abstract=true code with an assert().
  Suggested-by: Markus Armbruster <address@hidden>
* Try to make test code a bit more clear
---
 hw/acpi/acpi_interface.c       |  1 +
 hw/arm/boot.c                  |  1 +
 hw/core/fw-path-provider.c     |  1 +
 hw/core/hotplug.c              |  1 +
 hw/core/nmi.c                  |  1 +
 hw/core/stream.c               |  1 +
 hw/intc/intc.c                 |  1 +
 hw/ipmi/ipmi.c                 |  1 +
 hw/isa/isa-bus.c               |  1 +
 hw/ppc/pnv_xscom.c             |  1 +
 hw/timer/m48t59.c              |  1 +
 qom/object.c                   |  2 ++
 qom/object_interfaces.c        |  1 +
 tests/check-qom-interface.c    |  1 +
 tests/device-introspect-test.c | 58 +++++++++++++++++++++++++++++++++++++++---
 15 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/hw/acpi/acpi_interface.c b/hw/acpi/acpi_interface.c
index 6583917..49388a9 100644
--- a/hw/acpi/acpi_interface.c
+++ b/hw/acpi/acpi_interface.c
@@ -16,6 +16,7 @@ static void register_types(void)
     static const TypeInfo acpi_dev_if_info = {
         .name          = TYPE_ACPI_DEVICE_IF,
         .parent        = TYPE_INTERFACE,
+        .abstract = true,
         .class_size = sizeof(AcpiDeviceIfClass),
     };
 
diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index ff621e4..65c59b5 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -1031,6 +1031,7 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info 
*info)
 static const TypeInfo arm_linux_boot_if_info = {
     .name = TYPE_ARM_LINUX_BOOT_IF,
     .parent = TYPE_INTERFACE,
+    .abstract = true,
     .class_size = sizeof(ARMLinuxBootIfClass),
 };
 
diff --git a/hw/core/fw-path-provider.c b/hw/core/fw-path-provider.c
index 33b9983..96f3131 100644
--- a/hw/core/fw-path-provider.c
+++ b/hw/core/fw-path-provider.c
@@ -42,6 +42,7 @@ char *fw_path_provider_try_get_dev_path(Object *o, BusState 
*bus,
 static const TypeInfo fw_path_provider_info = {
     .name          = TYPE_FW_PATH_PROVIDER,
     .parent        = TYPE_INTERFACE,
+    .abstract      = true,
     .class_size    = sizeof(FWPathProviderClass),
 };
 
diff --git a/hw/core/hotplug.c b/hw/core/hotplug.c
index 17ac986..f74fba5 100644
--- a/hw/core/hotplug.c
+++ b/hw/core/hotplug.c
@@ -60,6 +60,7 @@ void hotplug_handler_unplug(HotplugHandler *plug_handler,
 static const TypeInfo hotplug_handler_info = {
     .name          = TYPE_HOTPLUG_HANDLER,
     .parent        = TYPE_INTERFACE,
+    .abstract      = true,
     .class_size = sizeof(HotplugHandlerClass),
 };
 
diff --git a/hw/core/nmi.c b/hw/core/nmi.c
index bfd0896..403edd3 100644
--- a/hw/core/nmi.c
+++ b/hw/core/nmi.c
@@ -76,6 +76,7 @@ void nmi_monitor_handle(int cpu_index, Error **errp)
 static const TypeInfo nmi_info = {
     .name          = TYPE_NMI,
     .parent        = TYPE_INTERFACE,
+    .abstract      = true,
     .class_size    = sizeof(NMIClass),
 };
 
diff --git a/hw/core/stream.c b/hw/core/stream.c
index 4439ecd..db7f90b 100644
--- a/hw/core/stream.c
+++ b/hw/core/stream.c
@@ -21,6 +21,7 @@ stream_can_push(StreamSlave *sink, StreamCanPushNotifyFn 
notify,
 static const TypeInfo stream_slave_info = {
     .name          = TYPE_STREAM_SLAVE,
     .parent        = TYPE_INTERFACE,
+    .abstract      = true,
     .class_size = sizeof(StreamSlaveClass),
 };
 
diff --git a/hw/intc/intc.c b/hw/intc/intc.c
index 2e1e29e..9373546 100644
--- a/hw/intc/intc.c
+++ b/hw/intc/intc.c
@@ -29,6 +29,7 @@
 static const TypeInfo intctrl_info = {
     .name = TYPE_INTERRUPT_STATS_PROVIDER,
     .parent = TYPE_INTERFACE,
+    .abstract = true,
     .class_size = sizeof(InterruptStatsProviderClass),
 };
 
diff --git a/hw/ipmi/ipmi.c b/hw/ipmi/ipmi.c
index 5cf1caa..c255499 100644
--- a/hw/ipmi/ipmi.c
+++ b/hw/ipmi/ipmi.c
@@ -86,6 +86,7 @@ static void ipmi_interface_class_init(ObjectClass *class, 
void *data)
 static TypeInfo ipmi_interface_type_info = {
     .name = TYPE_IPMI_INTERFACE,
     .parent = TYPE_INTERFACE,
+    .abstract = true,
     .class_size = sizeof(IPMIInterfaceClass),
     .class_init = ipmi_interface_class_init,
 };
diff --git a/hw/isa/isa-bus.c b/hw/isa/isa-bus.c
index 9d07b11..a1cad86 100644
--- a/hw/isa/isa-bus.c
+++ b/hw/isa/isa-bus.c
@@ -41,6 +41,7 @@ static void isa_bus_class_init(ObjectClass *klass, void *data)
 static const TypeInfo isa_dma_info = {
     .name = TYPE_ISADMA,
     .parent = TYPE_INTERFACE,
+    .abstract = true,
     .class_size = sizeof(IsaDmaClass),
 };
 
diff --git a/hw/ppc/pnv_xscom.c b/hw/ppc/pnv_xscom.c
index 8da2718..642f104 100644
--- a/hw/ppc/pnv_xscom.c
+++ b/hw/ppc/pnv_xscom.c
@@ -192,6 +192,7 @@ void pnv_xscom_realize(PnvChip *chip, Error **errp)
 static const TypeInfo pnv_xscom_interface_info = {
     .name = TYPE_PNV_XSCOM_INTERFACE,
     .parent = TYPE_INTERFACE,
+    .abstract = true,
     .class_size = sizeof(PnvXScomInterfaceClass),
 };
 
diff --git a/hw/timer/m48t59.c b/hw/timer/m48t59.c
index e46ca88..42c5fc7 100644
--- a/hw/timer/m48t59.c
+++ b/hw/timer/m48t59.c
@@ -884,6 +884,7 @@ static void m48txx_sysbus_concrete_class_init(ObjectClass 
*klass, void *data)
 static const TypeInfo nvram_info = {
     .name = TYPE_NVRAM,
     .parent = TYPE_INTERFACE,
+    .abstract = true,
     .class_size = sizeof(NvramClass),
 };
 
diff --git a/qom/object.c b/qom/object.c
index 7a05e35..d93989a 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -272,6 +272,8 @@ static void type_initialize(TypeImpl *ti)
 
     ti->class_size = type_class_get_size(ti);
     ti->instance_size = type_object_get_size(ti);
+    /* types with zero instance_size can't be instantiated, must be abstract */
+    assert(ti->instance_size > 0 || ti->abstract);
 
     ti->class = g_malloc0(ti->class_size);
 
diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
index ded4d84..f6dc46c 100644
--- a/qom/object_interfaces.c
+++ b/qom/object_interfaces.c
@@ -217,6 +217,7 @@ static void register_types(void)
     static const TypeInfo uc_interface_info = {
         .name          = TYPE_USER_CREATABLE,
         .parent        = TYPE_INTERFACE,
+        .abstract      = true,
         .class_size = sizeof(UserCreatableClass),
     };
 
diff --git a/tests/check-qom-interface.c b/tests/check-qom-interface.c
index f87c9aa..560b7e2 100644
--- a/tests/check-qom-interface.c
+++ b/tests/check-qom-interface.c
@@ -36,6 +36,7 @@ typedef struct TestIfClass {
 static const TypeInfo test_if_info = {
     .name          = TYPE_TEST_IF,
     .parent        = TYPE_INTERFACE,
+    .abstract      = true,
     .class_size = sizeof(TestIfClass),
 };
 
diff --git a/tests/device-introspect-test.c b/tests/device-introspect-test.c
index 37debc1..4fa8d29 100644
--- a/tests/device-introspect-test.c
+++ b/tests/device-introspect-test.c
@@ -20,18 +20,24 @@
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "qapi/qmp/qstring.h"
+#include "qapi/qmp/qbool.h"
+#include "qapi/qmp/qdict.h"
 #include "libqtest.h"
 
 const char common_args[] = "-nodefaults -machine none";
 
-static QList *device_type_list(bool abstract)
+static QList *qom_list_types(const char *implements, bool abstract)
 {
     QDict *resp;
     QList *ret;
+    QDict *args = qdict_new();
 
+    qdict_put(args, "abstract", qbool_from_bool(abstract));
+    if (implements) {
+        qdict_put(args, "implements", qstring_from_str(implements));
+    }
     resp = qmp("{'execute': 'qom-list-types',"
-               " 'arguments': {'implements': 'device', 'abstract': %i}}",
-               abstract);
+               " 'arguments': %p }", args);
     g_assert(qdict_haskey(resp, "return"));
     ret = qdict_get_qlist(resp, "return");
     QINCREF(ret);
@@ -39,6 +45,11 @@ static QList *device_type_list(bool abstract)
     return ret;
 }
 
+static QList *device_type_list(bool abstract)
+{
+    return qom_list_types("device", abstract);
+}
+
 static void test_one_device(const char *type)
 {
     QDict *resp;
@@ -110,6 +121,46 @@ static void test_device_intro_concrete(void)
     qtest_end();
 }
 
+static void test_abstract_interfaces(void)
+{
+    QList *all_types;
+    QList *obj_types;
+    QListEntry *ae;
+
+    qtest_start(common_args);
+    /* qom-list-types implements=interface would return any type
+     * that implements _any_ interface (not just interface types),
+     * so use a trick to find the interface type names:
+     * 1) list all non-abstract types
+     * 2) list all non-abstract object types
+     * 3) Look for items in (1) that are not in (2)
+     */
+    all_types = qom_list_types(NULL, false);
+    obj_types = qom_list_types("object", false);
+
+    QLIST_FOREACH_ENTRY(all_types, ae) {
+        QDict *at = qobject_to_qdict(qlist_entry_obj(ae));
+        const char *aname = qdict_get_str(at, "name");
+        QListEntry *oe;
+        const char *found = NULL;
+
+        QLIST_FOREACH_ENTRY(obj_types, oe) {
+            QDict *ot = qobject_to_qdict(qlist_entry_obj(oe));
+            const char *oname = qdict_get_str(ot, "name");
+            if (!strcmp(aname, oname)) {
+                found = oname;
+                break;
+            }
+        }
+
+        g_assert(found);
+    }
+
+    QDECREF(all_types);
+    QDECREF(obj_types);
+    qtest_end();
+}
+
 int main(int argc, char **argv)
 {
     g_test_init(&argc, &argv, NULL);
@@ -118,6 +169,7 @@ int main(int argc, char **argv)
     qtest_add_func("device/introspect/none", test_device_intro_none);
     qtest_add_func("device/introspect/abstract", test_device_intro_abstract);
     qtest_add_func("device/introspect/concrete", test_device_intro_concrete);
+    qtest_add_func("device/introspect/abstract-interfaces", 
test_abstract_interfaces);
 
     return g_test_run();
 }
-- 
2.7.4