qemu-option: Add support for merged QemuOptsLists

Add support for option lists which are merged together, so that
"-listname foo=bar -listname bar=baz" is equivalent to "-listname
foo=bar,bar=baz" rather than generating two separate lists of options.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andrzej Zaborowski <andrew.zaborowski@intel.com>

2 files changed, 7 insertions, 1 deletions

diff --git a/qemu-option.c b/qemu-option.c
index 4626ccfe54..35cd609f75 100644
--- a/qemu-option.c
+++ b/qemu-option.c
@@ -741,13 +741,18 @@ QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id, int fail_if_exist
         }
         opts = qemu_opts_find(list, id);
         if (opts != NULL) {
-            if (fail_if_exists) {
+            if (fail_if_exists && !list->merge_lists) {
                 qerror_report(QERR_DUPLICATE_ID, id, list->name);
                 return NULL;
             } else {
                 return opts;
             }
         }
+    } else if (list->merge_lists) {
+        opts = qemu_opts_find(list, NULL);
+        if (opts) {
+            return opts;
+        }
     }
     opts = g_malloc0(sizeof(*opts));
     if (id) {
diff --git a/qemu-option.h b/qemu-option.h
index e6f61e6e35..3ca00c3cec 100644
--- a/qemu-option.h
+++ b/qemu-option.h
@@ -100,6 +100,7 @@ typedef struct QemuOptDesc {
 struct QemuOptsList {
     const char *name;
     const char *implied_opt_name;
+    bool merge_lists;  /* Merge multiple uses of option into a single list? */
     QTAILQ_HEAD(, QemuOpts) head;
     QemuOptDesc desc[];
 };