Re: [Qemu-devel] [PATCH v2 2/8] net: List available netdevs with "-netdev help"

[Eric Blake]

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 
Signed-off-by: Thomas Huth 
---
  net/net.c | 37 -
  1 file changed, 36 insertions(+), 1 deletion(-)



Reviewed-by: Eric Blake 

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.   +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

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

[Thomas Huth]

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 
Signed-off-by: Thomas Huth 
---
 net/net.c | 37 -
 1 file changed, 36 insertions(+), 1 deletion(-)

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");
 
-- 
1.8.3.1