Commit 0340d819d0 for qemu.org

commit 0340d819d08dcb6694543aaa02af9478c51de1a2
Author: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>
Date:   Thu May 14 10:23:01 2026 -0700

    target-info: introduce TargetInfo in QOM

    For the single-binary, we want to be able to retrieve at runtime the
    current target among the different ones available.
    A consequence is that we can't rely on existing target_info() definition
    since it will create a conflict once more than one target is available.

    To solve this, we add TargetInfo in QOM, with this hierarchy.
    We define one class "target-info-X" per target, that inherits from
    abstract class "target-info". Using concrete vs abstract class ensure we
    can easily filter "target-info-X" from all QOM types.
    Associated TargetInfo is directly set through class initialization,
    without relying on any instance.

    For user mode, we simply define target_info() like it was done
    previously. In this patch, we keep the same definition for system-mode
    also, and it will be replaced in next commits.

    We will introduce detection of target from QOM, so we need to make sure
    those types are registered early.

    Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
    Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
    Link: https://lore.kernel.org/qemu-devel/20260514172303.1484273-4-pierrick.bouvier@oss.qualcomm.com
    Signed-off-by: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>

diff --git a/configs/targets/aarch64-softmmu.c b/configs/targets/aarch64-softmmu.c
index 82ccb57575..75d95b0e74 100644
--- a/configs/targets/aarch64-softmmu.c
+++ b/configs/targets/aarch64-softmmu.c
@@ -8,6 +8,7 @@

 #include "qemu/osdep.h"
 #include "qemu/target-info-impl.h"
+#include "qemu/target-info-init.h"
 #include "hw/arm/machines-qom.h"
 #include "target/arm/cpu-qom.h"
 #include "target/arm/cpu-param.h"
@@ -23,7 +24,4 @@ static const TargetInfo target_info_aarch64_system = {
     .page_bits_init = TARGET_PAGE_BITS_LEGACY,
 };

-const TargetInfo *target_info(void)
-{
-    return &target_info_aarch64_system;
-}
+target_info_init(target_info_aarch64_system)
diff --git a/configs/targets/arm-softmmu.c b/configs/targets/arm-softmmu.c
index 18940e51e5..73546fa573 100644
--- a/configs/targets/arm-softmmu.c
+++ b/configs/targets/arm-softmmu.c
@@ -8,6 +8,7 @@

 #include "qemu/osdep.h"
 #include "qemu/target-info-impl.h"
+#include "qemu/target-info-init.h"
 #include "hw/arm/machines-qom.h"
 #include "target/arm/cpu-qom.h"
 #include "target/arm/cpu-param.h"
@@ -23,7 +24,4 @@ static const TargetInfo target_info_arm_system = {
     .page_bits_init = TARGET_PAGE_BITS_LEGACY,
 };

-const TargetInfo *target_info(void)
-{
-    return &target_info_arm_system;
-}
+target_info_init(target_info_arm_system)
diff --git a/include/qemu/module.h b/include/qemu/module.h
index 9885ac9afb..fccf017bf9 100644
--- a/include/qemu/module.h
+++ b/include/qemu/module.h
@@ -43,6 +43,7 @@ typedef enum {
     MODULE_INIT_MIGRATION,
     MODULE_INIT_BLOCK,
     MODULE_INIT_OPTS,
+    MODULE_INIT_TARGET_INFO,
     MODULE_INIT_QOM,
     MODULE_INIT_TRACE,
     MODULE_INIT_XEN_BACKEND,
diff --git a/include/qemu/target-info-init.h b/include/qemu/target-info-init.h
new file mode 100644
index 0000000000..32c323a7ef
--- /dev/null
+++ b/include/qemu/target-info-init.h
@@ -0,0 +1,58 @@
+/*
+ * QEMU target info initialization
+ *
+ * Copyright (c) Qualcomm
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This file is included by each file defining a TargetInfo structure and is
+ * responsible for registering it.
+ */
+
+#ifndef QEMU_TARGET_INFO_INIT_H
+#define QEMU_TARGET_INFO_INIT_H
+
+#define DEFINE_TARGET_INFO_TYPE(info)                                       \
+static void do_qemu_init_target_info(void)                                  \
+{                                                                           \
+    type_register_static(&info);                                            \
+}                                                                           \
+module_init(do_qemu_init_target_info, MODULE_INIT_TARGET_INFO)
+
+#ifdef COMPILING_PER_TARGET
+#ifdef CONFIG_USER_ONLY
+
+/*
+ * User mode does not support multiple targets in the same binary, so just
+ * define target_info().
+ */
+#define target_info_init(ti_var)        \
+const TargetInfo *target_info(void)     \
+{                                       \
+    return &ti_var;                     \
+}
+
+#else /* CONFIG_USER_ONLY */
+
+#include "qemu/target-info-qom.h"
+#include "qom/object.h"
+
+#define target_info_init(ti_var)                                            \
+const TargetInfo *target_info(void)                                         \
+{                                                                           \
+    return &ti_var;                                                         \
+}                                                                           \
+                                                                            \
+static const TypeInfo target_info_qom_target_type_info = {                  \
+    .name =  TYPE_TARGET_INFO"-"TARGET_NAME,                                \
+    .parent = TYPE_TARGET_INFO,                                             \
+    .instance_size = sizeof(TargetInfoQom),                                 \
+    .class_size = sizeof(TargetInfoQomClass),                               \
+    .class_data = &ti_var,                                                  \
+};                                                                          \
+DEFINE_TARGET_INFO_TYPE(target_info_qom_target_type_info)
+
+#endif /* CONFIG_USER_ONLY */
+#endif /* COMPILING_PER_TARGET */
+
+#endif /* QEMU_TARGET_INFO_INIT_H */
diff --git a/include/qemu/target-info-qom.h b/include/qemu/target-info-qom.h
new file mode 100644
index 0000000000..585995c7ad
--- /dev/null
+++ b/include/qemu/target-info-qom.h
@@ -0,0 +1,28 @@
+/*
+ * QEMU target info QOM types
+ *
+ * Copyright (c) Qualcomm
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef QEMU_TARGET_INFO_QOM_H
+#define QEMU_TARGET_INFO_QOM_H
+
+#include "qemu/target-info-impl.h"
+#include "qom/object.h"
+
+#define TYPE_TARGET_INFO "target-info"
+
+typedef struct TargetInfoQom {
+    Object parent_obj;
+} TargetInfoQom;
+
+typedef struct TargetInfoQomClass {
+    ObjectClass parent_class;
+    const TargetInfo *target_info;
+} TargetInfoQomClass;
+
+OBJECT_DECLARE_TYPE(TargetInfoQom, TargetInfoQomClass, TARGET_INFO)
+
+#endif /* QEMU_TARGET_INFO_QOM_H */
diff --git a/system/vl.c b/system/vl.c
index d2f4044e5d..e44da0941d 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -2889,6 +2889,8 @@ void qemu_init(int argc, char **argv)

     os_setup_limits();

+    module_call_init(MODULE_INIT_TARGET_INFO);
+
     module_init_info(qemu_modinfo);
     module_allow_arch(target_name());

diff --git a/target-info-qom.c b/target-info-qom.c
index 7fd58d2481..79752366b6 100644
--- a/target-info-qom.c
+++ b/target-info-qom.c
@@ -7,7 +7,11 @@
  */

 #include "qemu/osdep.h"
+#include "qapi/error.h"
 #include "qom/object.h"
+#include "qemu/target-info-impl.h"
+#include "qemu/target-info-init.h"
+#include "qemu/target-info-qom.h"
 #include "hw/arm/machines-qom.h"

 static const TypeInfo target_info_types[] = {
@@ -22,3 +26,23 @@ static const TypeInfo target_info_types[] = {
 };

 DEFINE_TYPES(target_info_types)
+
+static void target_info_qom_class_init(ObjectClass *oc, const void * data)
+{
+    TargetInfoQomClass *klass = TARGET_INFO_CLASS(oc);
+    klass->target_info = data;
+}
+
+static const TypeInfo target_info_parent_type = {
+    .name = TYPE_TARGET_INFO,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(TargetInfoQom),
+    .class_size = sizeof(TargetInfoQomClass),
+    /* use class_base_init so children classes can set class_data accordingly */
+    .class_base_init = target_info_qom_class_init,
+    /* children classes will be concrete, which allows to easily query them
+     * without listing this parent class also */
+    .abstract = true,
+};
+
+DEFINE_TARGET_INFO_TYPE(target_info_parent_type)
diff --git a/target-info-stub.c b/target-info-stub.c
index 07d8647ed8..22b7911201 100644
--- a/target-info-stub.c
+++ b/target-info-stub.c
@@ -9,6 +9,7 @@
 #include "qemu/osdep.h"
 #include "qemu/target-info.h"
 #include "qemu/target-info-impl.h"
+#include "qemu/target-info-init.h"
 #include "hw/core/boards.h"
 #include "cpu.h"
 #include "exec/cpu-defs.h"
@@ -41,7 +42,4 @@ static const TargetInfo target_info_stub = {
 #endif
 };

-const TargetInfo *target_info(void)
-{
-    return &target_info_stub;
-}
+target_info_init(target_info_stub)
diff --git a/tests/qtest/fuzz/fuzz.c b/tests/qtest/fuzz/fuzz.c
index d235598961..de230d20e0 100644
--- a/tests/qtest/fuzz/fuzz.c
+++ b/tests/qtest/fuzz/fuzz.c
@@ -172,6 +172,7 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char ***envp)

     /* Initialize qgraph and modules */
     qos_graph_init();
+    module_call_init(MODULE_INIT_TARGET_INFO);
     module_call_init(MODULE_INIT_FUZZ_TARGET);
     module_call_init(MODULE_INIT_QOM);
     module_call_init(MODULE_INIT_LIBQOS);