qemu-option: Add qemu_opts_absorb_qdict()

This adds a function that adds all entries of a QDict to a QemuOpts if
the keys are known, and leaves only the rest in the QDict.

This way a single QDict of -drive options can be processed in multiple
places (generic block layer, block driver, backing file block driver,
etc.), where each part picks the options it knows. If at the end of the
process the QDict isn't empty, the user specified an invalid option.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

diff --git a/include/qemu/option.h b/include/qemu/option.h
index ba197cddcf2ced115ecfbbaea340d77672515e9b..bdb6d218b435fab78407da888a54f26457f7f54e 100644 (file)
--- a/include/qemu/option.h
+++ b/include/qemu/option.h
@@ -149,6 +149,7 @@ void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
 QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
                                Error **errp);
 QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict);
+void qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp);
 
 typedef int (*qemu_opts_loopfunc)(QemuOpts *opts, void *opaque);
 int qemu_opts_print(QemuOpts *opts, void *dummy);

diff --git a/util/qemu-option.c b/util/qemu-option.c
index 5a1d03c3313466619af9db2d5936b97f6719aca0..8b74bf1f7a24f512c08392687678067c3617c18b 100644 (file)
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -1066,6 +1066,40 @@ QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
     return opts;
 }
 
+/*
+ * Adds all QDict entries to the QemuOpts that can be added and removes them
+ * from the QDict. When this function returns, the QDict contains only those
+ * entries that couldn't be added to the QemuOpts.
+ */
+void qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp)
+{
+    const QDictEntry *entry, *next;
+
+    entry = qdict_first(qdict);
+
+    while (entry != NULL) {
+        Error *local_err = NULL;
+        OptsFromQDictState state = {
+            .errp = &local_err,
+            .opts = opts,
+        };
+
+        next = qdict_next(qdict, entry);
+
+        if (find_desc_by_name(opts->list->desc, entry->key)) {
+            qemu_opts_from_qdict_1(entry->key, entry->value, &state);
+            if (error_is_set(&local_err)) {
+                error_propagate(errp, local_err);
+                return;
+            } else {
+                qdict_del(qdict, entry->key);
+            }
+        }
+
+        entry = next;
+    }
+}
+
 /*
  * Convert from QemuOpts to QDict.
  * The QDict values are of type QString.