[08/27] util: Add qemu_opts_to_qdict_filtered()

Commit Message

Kevin Wolf Feb. 8, 2018, 7:23 p.m. UTC

This allows, given a QemuOpts for a QemuOptsList that was merged from
multiple QemuOptsList, to only consider those options that exist in one
specific list. Block drivers need this to separate format-layer create
options from protocol-level options.

Signed-off-by: Kevin Wolf <[e-mail]>
---
 include/qemu/option.h |  2 ++
 util/qemu-option.c    | 37 ++++++++++++++++++++++++++++++++-----
 2 files changed, 34 insertions(+), 5 deletions(-)

Comments

Max Reitz Feb. 9, 2018, 6:07 p.m. UTC | #1

On 2018-02-08 20:23, Kevin Wolf wrote:
> This allows, given a QemuOpts for a QemuOptsList that was merged from
> multiple QemuOptsList, to only consider those options that exist in one
> specific list. Block drivers need this to separate format-layer create
> options from protocol-level options.
> 
> Signed-off-by: Kevin Wolf <[e-mail]>
> ---
>  include/qemu/option.h |  2 ++
>  util/qemu-option.c    | 37 ++++++++++++++++++++++++++++++++-----
>  2 files changed, 34 insertions(+), 5 deletions(-)

Reviewed-by: Max Reitz <[e-mail]>

Eric Blake Feb. 15, 2018, 7:33 p.m. UTC | #2

On 02/08/2018 01:23 PM, Kevin Wolf wrote:
> This allows, given a QemuOpts for a QemuOptsList that was merged from
> multiple QemuOptsList, to only consider those options that exist in one
> specific list. Block drivers need this to separate format-layer create
> options from protocol-level options.
> 
> Signed-off-by: Kevin Wolf <[e-mail]>
> ---
>   include/qemu/option.h |  2 ++
>   util/qemu-option.c    | 37 ++++++++++++++++++++++++++++++++-----
>   2 files changed, 34 insertions(+), 5 deletions(-)

Is there any unit test coverage we should be adding, beyond the default 
we get when the list parameter is NULL?

But what you have looks sane;
Reviewed-by: Eric Blake <[e-mail]>

Patch

diff --git a/include/qemu/option.h b/include/qemu/option.h
index a88c5f02b1..197f80e79d 100644
--- a/include/qemu/option.h
+++ b/include/qemu/option.h
@@ -125,6 +125,8 @@  void qemu_opts_set_defaults(QemuOptsList *list, const char *params,
                             int permit_abbrev);
 QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
                                Error **errp);
+QDict *qemu_opts_to_qdict_filtered(QemuOpts *opts, QDict *qdict,
+                                   QemuOptsList *list, bool del);
 QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict);
 void qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp);
 
diff --git a/util/qemu-option.c b/util/qemu-option.c
index 553d3dc552..ba33bbe487 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -1004,14 +1004,18 @@  void qemu_opts_absorb_qdict(QemuOpts *opts, QDict *qdict, Error **errp)
 }
 
 /*
- * Convert from QemuOpts to QDict.
- * The QDict values are of type QString.
+ * Convert from QemuOpts to QDict. The QDict values are of type QString.
+ * If @list is given, only add those options to the QDict that are contained in
+ * the list. If @del is true, any options added to the QDict are removed from
+ * the QemuOpts, otherwise they remain there.
+ *
  * TODO We'll want to use types appropriate for opt->desc->type, but
  * this is enough for now.
  */
-QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)
+QDict *qemu_opts_to_qdict_filtered(QemuOpts *opts, QDict *qdict,
+                                   QemuOptsList *list, bool del)
 {
-    QemuOpt *opt;
+    QemuOpt *opt, *next;
 
     if (!qdict) {
         qdict = qdict_new();
@@ -1019,12 +1023,35 @@  QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)
     if (opts->id) {
         qdict_put_str(qdict, "id", opts->id);
     }
-    QTAILQ_FOREACH(opt, &opts->head, next) {
+    QTAILQ_FOREACH_SAFE(opt, &opts->head, next, next) {
+        if (list) {
+            QemuOptDesc *desc;
+            bool found = false;
+            for (desc = list->desc; desc->name; desc++) {
+                if (!strcmp(desc->name, opt->name)) {
+                    found = true;
+                    break;
+                }
+            }
+            if (!found) {
+                continue;
+            }
+        }
         qdict_put_str(qdict, opt->name, opt->str);
+        if (del) {
+            qemu_opt_del_all(opts, opt->name);
+        }
     }
     return qdict;
 }
 
+/* Copy all options in a QemuOpts to the given QDict. See
+ * qemu_opts_to_qdict_filtered() for details. */
+QDict *qemu_opts_to_qdict(QemuOpts *opts, QDict *qdict)
+{
+    return qemu_opts_to_qdict_filtered(opts, qdict, NULL, false);
+}
+
 /* Validate parsed opts against descriptions where no
  * descriptions were provided in the QemuOptsList.
  */