[PATCH] plugins: add plugin API to get args passed to binary

["demin.han" <demin.han@starfivetech.com>]

Why we need args?
When plugin outputs log files, only binary path can't distinguish multiple
runs if the binary passed with different args.
This is bad for CI using plugin.

Signed-off-by: demin.han <demin.han@starfivetech.com>
---
 include/qemu/qemu-plugin.h   | 11 +++++++++++
 plugins/api.c                | 16 ++++++++++++++++
 plugins/qemu-plugins.symbols |  1 +
 3 files changed, 28 insertions(+)

diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
index 622c9a0232..daf75c9f5a 100644
--- a/include/qemu/qemu-plugin.h
+++ b/include/qemu/qemu-plugin.h
@@ -837,6 +837,17 @@ bool qemu_plugin_bool_parse(const char *name, const char *val, bool *ret);
 QEMU_PLUGIN_API
 const char *qemu_plugin_path_to_binary(void);
 
+/**
+ * qemu_plugin_argv_to_binary() - argv to binary file being executed
+ *
+ * Return a string array representing the argv to the binary. For user-mode
+ * this is the main executable's argv. For system emulation we currently
+ * return NULL. The user should g_free() the string array once no longer
+ * needed.
+ */
+QEMU_PLUGIN_API
+const char **qemu_plugin_argv_to_binary(void);
+
 /**
  * qemu_plugin_start_code() - returns start of text segment
  *
diff --git a/plugins/api.c b/plugins/api.c
index 24ea64e2de..fa2735db03 100644
--- a/plugins/api.c
+++ b/plugins/api.c
@@ -485,6 +485,22 @@ const char *qemu_plugin_path_to_binary(void)
     return path;
 }
 
+const char **qemu_plugin_argv_to_binary(void)
+{
+    const char **argv = NULL;
+#ifdef CONFIG_USER_ONLY
+    int i, argc;
+    TaskState *ts = get_task_state(current_cpu);
+    argc = ts->bprm->argc;
+    argv = g_malloc(sizeof(char *) * (argc + 1));
+    for (i = 0; i < argc; ++i) {
+        argv[i] = g_strdup(ts->bprm->argv[i]);
+    }
+    argv[argc] = NULL;
+#endif
+    return argv;
+}
+
 uint64_t qemu_plugin_start_code(void)
 {
     uint64_t start = 0;
diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols
index 032661f9ea..532582effe 100644
--- a/plugins/qemu-plugins.symbols
+++ b/plugins/qemu-plugins.symbols
@@ -1,4 +1,5 @@
 {
+  qemu_plugin_argv_to_binary;
   qemu_plugin_bool_parse;
   qemu_plugin_end_code;
   qemu_plugin_entry_code;
-- 
2.46.1