net/slirp: Deprecate the [hub_id name] parameter tuple

The "name" in the [hub_id name] parameter tuple is the same as a
"netdev_id" (which should be unique), so specifying the hub_id here
is just redundant (it was likely just necessary in the past when
the network subsystem was still using "vlans" only and when it did
not use unique "id"s yet).

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

net/slirp.c

@@ -404,6 +404,8 @@ static SlirpState *slirp_lookup(Monitor *mon, const char *hub_id,
                 monitor_printf(mon, "unrecognized (hub-id, stackname) pair\n");
                 return NULL;
             }
+            warn_report("Using 'hub-id' is deprecated, specify the netdev id "
+                        "directly instead");
         } else {
             nc = qemu_find_netdev(name);
             if (!nc) {

qemu-deprecated.texi

@@ -104,6 +104,13 @@ The ``query-cpus'' command is replaced by the ``query-cpus-fast'' command.
 The ``arch'' output member of the ``query-cpus-fast'' command is
 replaced by the ``target'' output member.
 
+@section System emulator human monitor commands
+
+@subsection The hub_id parameter of 'hostfwd_add' / 'hostfwd_remove' (since 3.1)
+
+The @option{[hub_id name]} parameter tuple of the 'hostfwd_add' and
+'hostfwd_remove' HMP commands has been replaced by @option{netdev_id}.
+
 @section System emulator devices
 
 @subsection ivshmem (since 2.6.0)