[Qemu-block] [PATCH v14 20/21] net: convert to QObjectInputVisitor for -net/-netdev parsing

[Daniel P. Berrange]

The -net/-netdev command line parsing code uses OptsVisitor
for parsing options to populate NetLegacy or NetDev struct
respectively. Although those structs have nesting, the
OptsVisitor flattens them, so we must enable compatibility
options to auto-create structs. This allows the legacy
syntax

  -net tap,id=net0,vlan=3,fd=3,script=/bin/ifup-qemu

to be treated as equivalent to the modern QAPI based
syntax

  -net 
id=net0,vlan=3,opts.type=tap,opts.data.fd=3,opts.data.script=/bin/ifup-qemu

Signed-off-by: Daniel P. Berrange <address@hidden>
---
 net/net.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/net/net.c b/net/net.c
index ec984bf..de6bf8e 100644
--- a/net/net.c
+++ b/net/net.c
@@ -43,7 +43,7 @@
 #include "qemu/iov.h"
 #include "qemu/main-loop.h"
 #include "qapi-visit.h"
-#include "qapi/opts-visitor.h"
+#include "qapi/qobject-input-visitor.h"
 #include "sysemu/sysemu.h"
 #include "net/filter.h"
 #include "qapi/string-output-visitor.h"
@@ -1069,7 +1069,21 @@ int net_client_init(QemuOpts *opts, bool is_netdev, 
Error **errp)
     void *object = NULL;
     Error *err = NULL;
     int ret = -1;
-    Visitor *v = opts_visitor_new(opts);
+    /*
+     * Needs autocreate_lists=true in order support existing
+     * syntax for list options where the bare key is repeated
+     *
+     * Needs autocreate_struct_levels=3 in order to deal with
+     * 3 level nesting in NetLegacy option args, which was
+     * exposed as a flat namespace with OptVisitor
+     */
+    Visitor *v = qobject_input_visitor_new_opts(opts, true, 3, false, true,
+                                                &err);
+
+    if (err) {
+        error_propagate(errp, err);
+        return -1;
+    }
 
     {
         /* Parse convenience option format ip6-net=fec0::0[/64] */
-- 
2.7.4