commit 27c819244b8129a4742bfe43d255cdaa8528765d
author Thomas Huth <thuth@redhat.com> Thu Nov 10 13:52:23 2022 +0100
committer Jason Wang <jasowang@redhat.com> Fri Feb 17 13:31:33 2023 +0800
tree 11802ad608f8beeabe2ca36d5195ce8e09f74f47
parent c6941b3b9b7445f7760c462882f8397b9dc51e30

net: Restore printing of the help text with "-nic help"

Running QEMU with "-nic help" used to work in QEMU 5.2 and earlier versions
(it showed the available netdev backends), but this feature got broken during
some refactoring in version 6.0. Let's restore the old behavior, and while
we're at it, let's also print the available NIC models here now since this
option can be used to configure both, netdev backend and model in one go.

Fixes: ad6f932fe8 ("net: do not exit on "netdev_add help" monitor command")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/net.c

diff --git a/net/net.c b/net/net.c
index 476a4b7..e8cd95c 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1542,8 +1542,18 @@
     const char *type;
 
     type = qemu_opt_get(opts, "type");
-    if (type && g_str_equal(type, "none")) {
-        return 0;    /* Nothing to do, default_net is cleared in vl.c */
+    if (type) {
+        if (g_str_equal(type, "none")) {
+            return 0;    /* Nothing to do, default_net is cleared in vl.c */
+        }
+        if (is_help_option(type)) {
+            GPtrArray *nic_models = qemu_get_nic_models(TYPE_DEVICE);
+            show_netdevs();
+            printf("\n");
+            qemu_show_nic_models(type, (const char **)nic_models->pdata);
+            g_ptr_array_free(nic_models, true);
+            exit(0);
+        }
     }
 
     idx = nic_get_free_idx();