[v2,2/8] net: List available netdevs with "-netdev help"

Commit Message

Thomas Huth Feb. 20, 2018, 5:40 p.m. UTC

Other options like "-chardev" or "-device" feature a nice help text
with the available devices when being called with "help" or "?".
Since it is quite useful, especially if you want to see which network
backends have been compiled into the QEMU binary, let's provide such
a help text for "-netdev", too.

Reviewed-by: Paolo Bonzini <[e-mail]>
Signed-off-by: Thomas Huth <[e-mail]>
---
 net/net.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

Comments

Eric Blake Feb. 20, 2018, 10:28 p.m. UTC | #1

On 02/20/2018 11:40 AM, Thomas Huth wrote:
> Other options like "-chardev" or "-device" feature a nice help text
> with the available devices when being called with "help" or "?".
> Since it is quite useful, especially if you want to see which network
> backends have been compiled into the QEMU binary, let's provide such
> a help text for "-netdev", too.
> 
> Reviewed-by: Paolo Bonzini <[e-mail]>
> Signed-off-by: Thomas Huth <[e-mail]>
> ---
>   net/net.c | 37 ++++++++++++++++++++++++++++++++++++-
>   1 file changed, 36 insertions(+), 1 deletion(-)
> 

Reviewed-by: Eric Blake <[e-mail]>

Patch

diff --git a/net/net.c b/net/net.c
index e213a61..cf07e15 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1086,6 +1086,38 @@  static int net_client_init1(const void *object, bool is_netdev, Error **errp)
     return 0;
 }
 
+static void show_netdevs(void)
+{
+    int idx;
+    const char *available_netdevs[] = {
+        "socket",
+        "hubport",
+        "tap",
+#ifdef CONFIG_SLIRP
+        "user",
+#endif
+#ifdef CONFIG_L2TPV3
+        "l2tpv3",
+#endif
+#ifdef CONFIG_VDE
+        "vde",
+#endif
+#ifdef CONFIG_NET_BRIDGE
+        "bridge",
+#endif
+#ifdef CONFIG_NETMAP
+        "netmap",
+#endif
+#ifdef CONFIG_POSIX
+        "vhost-user",
+#endif
+    };
+
+    printf("Available netdev backend types:\n");
+    for (idx = 0; idx < ARRAY_SIZE(available_netdevs); idx++) {
+        puts(available_netdevs[idx]);
+    }
+}
 
 int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
 {
@@ -1094,7 +1126,10 @@  int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
     int ret = -1;
     Visitor *v = opts_visitor_new(opts);
 
-    {
+    if (is_netdev && is_help_option(qemu_opt_get(opts, "type"))) {
+        show_netdevs();
+        exit(0);
+    } else {
         /* Parse convenience option format ip6-net=fec0::0[/64] */
         const char *ip6_net = qemu_opt_get(opts, "ipv6-net");