QemuOpts: add def_value_str to QemuOptDesc

Add def_value_str (default value) to QemuOptDesc, to replace function of the
default value in QEMUOptionParameter.

Improve qemu_opts_get_* functions: if find opt, return opt->str; otherwise,
if desc->def_value_str is set, return desc->def_value_str; otherwise, return
input defval.

Improve qemu_opts_print: if option is set, print opt->str; otherwise, if
desc->def_value_str is set, print it.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/qemu/option.h b/include/qemu/option.h
index 1077b69..c3b0a91 100644
--- a/include/qemu/option.h
+++ b/include/qemu/option.h
@@ -99,6 +99,7 @@ typedef struct QemuOptDesc {
     const char *name;
     enum QemuOptType type;
     const char *help;
+    const char *def_value_str;
 } QemuOptDesc;
 
 struct QemuOptsList {