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 82ccb5757599de4f8eae39ee9e92c3fc3a03e042..75d95b0e7436db8cb20749f7dd10d4ab5a79e0a2 100644 (file)
--- 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 18940e51e558a5256d0ab1b617017fc1b5e2a4e1..73546fa573712228bab54be07251adb6f06f9e68 100644 (file)
--- 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 9885ac9afb3dd1f8ce95931ff930410a250eb690..fccf017bf9e805adf03944433d59eecbf2f453ed 100644 (file)
--- 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 (file)
index 0000000..32c323a
--- /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 (file)
index 0000000..585995c
--- /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 d2f4044e5d8e9d0a504c323d3fae0abf355c4a22..e44da0941d400b4e6d4446fef197657bbb478194 100644 (file)
--- 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 7fd58d24818068121b760eb8d9cf24a98951a35d..79752366b61669ed3919699c9d0ca2561cb37f5b 100644 (file)
--- 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 07d8647ed8e3bc30f75ecd59a8776d20abea03ae..22b7911201cb224d188ff508136e45da1dd62398 100644 (file)
--- 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 d23559896165726a60f9581be78023a2a5efa2a1..de230d20e0fc66c57ec2a1ce1c81d9c814113d29 100644 (file)
--- 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);