As the list of options isn't fixed we do all the parsing by hand.
Without any named arguments we automatically fill the "file" option
with the value give so check if it is requesting help and dump some
basic usage text.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240729144414.830369-15-alex.bennee@linaro.org>

diff --git a/plugins/loader.c b/plugins/loader.c
index 513a429c57..ebc01da9c6 100644
--- a/plugins/loader.c
+++ b/plugins/loader.c
@@ -18,6 +18,7 @@
 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
 #include "qemu/config-file.h"
+#include "qemu/help_option.h"
 #include "qapi/error.h"
 #include "qemu/lockable.h"
 #include "qemu/option.h"
@@ -98,7 +99,12 @@ static int plugin_add(void *opaque, const char *name, const char *value,
     bool is_on;
     char *fullarg;
 
-    if (strcmp(name, "file") == 0) {
+    if (is_help_option(value)) {
+        printf("Plugin options\n");
+        printf("  file=<path/to/plugin.so>\n");
+        printf("  plugin specific arguments\n");
+        exit(0);
+    } else if (strcmp(name, "file") == 0) {
         if (strcmp(value, "") == 0) {
             error_setg(errp, "requires a non-empty argument");
             return 1;
-- 
2.39.2