plugins/api: split out binary path/start/end/entry code

To move the main api.c to a single build compilation object we need to
start splitting out user and system specific code. As we need to grob
around host headers we move these particular helpers into the *-user
mode directories.

The binary/start/end/entry helpers are all NOPs for system mode.

While using the plugin-api.c.inc trick means we build for both
linux-user and bsd-user the BSD user-mode command line is still
missing -plugin. This can be enabled once we have reliable check-tcg
tests working for the BSDs.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20250304222439.2035603-27-alex.bennee@linaro.org>

8 files changed, 115 insertions, 44 deletions

diff --git a/bsd-user/meson.build b/bsd-user/meson.build
index 39bad0a..37b7cd6 100644
--- a/bsd-user/meson.build
+++ b/bsd-user/meson.build
@@ -13,6 +13,7 @@ bsd_user_ss.add(files(
   'elfload.c',
   'main.c',
   'mmap.c',
+  'plugin-api.c',
   'signal.c',
   'strace.c',
   'uaccess.c',
diff --git a/bsd-user/plugin-api.c b/bsd-user/plugin-api.c
new file mode 100644
index 0000000..6ccef7e
--- /dev/null
+++ b/bsd-user/plugin-api.c
@@ -0,0 +1,15 @@
+/*
+ * QEMU Plugin API - bsd-user-mode only implementations
+ *
+ * Common user-mode only APIs are in plugins/api-user. These helpers
+ * are only specific to bsd-user.
+ *
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ * Copyright (C) 2019-2025, Linaro
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu.h"
+#include "common-user/plugin-api.c.inc"
diff --git a/common-user/plugin-api.c.inc b/common-user/plugin-api.c.inc
new file mode 100644
index 0000000..5b8a139
--- /dev/null
+++ b/common-user/plugin-api.c.inc
@@ -0,0 +1,43 @@
+/*
+ * QEMU Plugin API - *-user-mode only implementations
+ *
+ * Common user-mode only APIs are in plugins/api-user. These helpers
+ * are only specific to the *-user frontends.
+ *
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ * Copyright (C) 2019-2025, Linaro
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
+#include "qemu/plugin.h"
+#include "qemu.h"
+
+/*
+ * Binary path, start and end locations. Host specific due to TaskState.
+ */
+const char *qemu_plugin_path_to_binary(void)
+{
+    TaskState *ts = get_task_state(current_cpu);
+    return g_strdup(ts->bprm->filename);
+}
+
+uint64_t qemu_plugin_start_code(void)
+{
+    TaskState *ts = get_task_state(current_cpu);
+    return ts->info->start_code;
+}
+
+uint64_t qemu_plugin_end_code(void)
+{
+    TaskState *ts = get_task_state(current_cpu);
+    return ts->info->end_code;
+}
+
+uint64_t qemu_plugin_entry_code(void)
+{
+    TaskState *ts = get_task_state(current_cpu);
+    return ts->info->entry;
+}
diff --git a/linux-user/meson.build b/linux-user/meson.build
index f75b4fe..f47a213 100644
--- a/linux-user/meson.build
+++ b/linux-user/meson.build
@@ -27,6 +27,7 @@ linux_user_ss.add(libdw)
 linux_user_ss.add(when: 'TARGET_HAS_BFLT', if_true: files('flatload.c'))
 linux_user_ss.add(when: 'TARGET_I386', if_true: files('vm86.c'))
 linux_user_ss.add(when: 'CONFIG_ARM_COMPATIBLE_SEMIHOSTING', if_true: files('semihost.c'))
+linux_user_ss.add(when: 'CONFIG_TCG_PLUGINS', if_true: files('plugin-api.c'))
 
 syscall_nr_generators = {}
 
diff --git a/linux-user/plugin-api.c b/linux-user/plugin-api.c
new file mode 100644
index 0000000..66755df
--- /dev/null
+++ b/linux-user/plugin-api.c
@@ -0,0 +1,15 @@
+/*
+ * QEMU Plugin API - linux-user-mode only implementations
+ *
+ * Common user-mode only APIs are in plugins/api-user. These helpers
+ * are only specific to linux-user.
+ *
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ * Copyright (C) 2019-2025, Linaro
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu.h"
+#include "common-user/plugin-api.c.inc"
diff --git a/plugins/api-system.c b/plugins/api-system.c
new file mode 100644
index 0000000..cb0dd8f
--- /dev/null
+++ b/plugins/api-system.c
@@ -0,0 +1,39 @@
+/*
+ * QEMU Plugin API - System specific implementations
+ *
+ * This provides the APIs that have a specific system implementation
+ * or are only relevant to system-mode.
+ *
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ * Copyright (C) 2019-2025, Linaro
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
+#include "qemu/plugin.h"
+
+/*
+ * In system mode we cannot trace the binary being executed so the
+ * helpers all return NULL/0.
+ */
+const char *qemu_plugin_path_to_binary(void)
+{
+    return NULL;
+}
+
+uint64_t qemu_plugin_start_code(void)
+{
+    return 0;
+}
+
+uint64_t qemu_plugin_end_code(void)
+{
+    return 0;
+}
+
+uint64_t qemu_plugin_entry_code(void)
+{
+    return 0;
+}
diff --git a/plugins/api.c b/plugins/api.c
index c3ba1e9..ffccd71 100644
--- a/plugins/api.c
+++ b/plugins/api.c
@@ -472,49 +472,6 @@ bool qemu_plugin_bool_parse(const char *name, const char *value, bool *ret)
 }
 
 /*
- * Binary path, start and end locations
- */
-const char *qemu_plugin_path_to_binary(void)
-{
-    char *path = NULL;
-#ifdef CONFIG_USER_ONLY
-    TaskState *ts = get_task_state(current_cpu);
-    path = g_strdup(ts->bprm->filename);
-#endif
-    return path;
-}
-
-uint64_t qemu_plugin_start_code(void)
-{
-    uint64_t start = 0;
-#ifdef CONFIG_USER_ONLY
-    TaskState *ts = get_task_state(current_cpu);
-    start = ts->info->start_code;
-#endif
-    return start;
-}
-
-uint64_t qemu_plugin_end_code(void)
-{
-    uint64_t end = 0;
-#ifdef CONFIG_USER_ONLY
-    TaskState *ts = get_task_state(current_cpu);
-    end = ts->info->end_code;
-#endif
-    return end;
-}
-
-uint64_t qemu_plugin_entry_code(void)
-{
-    uint64_t entry = 0;
-#ifdef CONFIG_USER_ONLY
-    TaskState *ts = get_task_state(current_cpu);
-    entry = ts->info->entry;
-#endif
-    return entry;
-}
-
-/*
  * Create register handles.
  *
  * We need to create a handle for each register so the plugin
diff --git a/plugins/meson.build b/plugins/meson.build
index f782080..9c9bc9e 100644
--- a/plugins/meson.build
+++ b/plugins/meson.build
@@ -59,7 +59,7 @@ if host_os == 'windows'
 endif
 
 user_ss.add(files('user.c'))
-system_ss.add(files('system.c'))
+system_ss.add(files('system.c', 'api-system.c'))
 
 common_ss.add(files('loader.c'))