Re: [Qemu-devel] [PATCH 16/19] Add a query-netdev command to QMP

[Anthony Liguori <anthony@codemonkey.ws>]

On 06/07/2010 09:42 AM, Daniel P. Berrange wrote:
> This adds a new QMP command called query-netdev to provide information
> about the available netdev backends in the QEMU binary. There is no
> existing '-netdev ?' support, but if there was, this would obsolete it
>
> The data format looks like
>
>      [
>          {
>              "name": "user",
>              "props": [
>                  {
>                      "name": "type",
>                      "help": "net client type (nic, tap etc.)",
>                      "type": "string"
>                  },
>    

I'm not sure it's a good idea to expose the help text.  That bakes it 
into the ABI which seems bad.

Regards,

Anthony Liguori

>                  {
>                      "name": "name",
>                      "help": "identifier for monitor commands",
>                      "type": "string"
>                  },
>                  {
>                      "name": "hostname",
>                      "help": "client hostname reported by the builtin DHCP server",
>                      "type": "string"
>                  },
>                  ...
>              ]
>          }
>          {
>              "name": "tap",
>              "props": [
>                  {
>                      "name": "type",
>                      "help": "net client type (nic, tap etc.)",
>                      "type": "string"
>                  },
>                  {
>                      "name": "ifname",
>                      "help": "interface name",
>                      "type": "string"
>                  },
>                  ...
>              ]
>          }
>          ...
>      ]
>
> Signed-off-by: Daniel P. Berrange<berrange@redhat.com>
> ---
>   monitor.c     |    8 ++++++++
>   net.c         |   49 +++++++++++++++++++++++++++++++++++++++++++++++++
>   net.h         |    2 ++
>   qemu-option.c |    4 ++++
>   qemu-option.h |    4 ++++
>   5 files changed, 67 insertions(+), 0 deletions(-)
>
> diff --git a/monitor.c b/monitor.c
> index 1c5157d..19f42f3 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -2552,6 +2552,14 @@ static const mon_cmd_t info_cmds[] = {
>           .mhandler.info_new = do_info_argv,
>       },
>       {
> +        .name       = "netdev",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "list valid netdev backend types",
> +        .user_print = monitor_user_noop,
> +        .mhandler.info_new = do_info_netdev,
> +    },
> +    {
>           .name       = "network",
>           .args_type  = "",
>           .params     = "",
> diff --git a/net.c b/net.c
> index 5349001..90929d4 100644
> --- a/net.c
> +++ b/net.c
> @@ -36,6 +36,8 @@
>   #include "qemu-common.h"
>   #include "qemu_socket.h"
>   #include "hw/qdev.h"
> +#include "qjson.h"
> +#include "qlist.h"
>
>   static QTAILQ_HEAD(, VLANState) vlans;
>   static QTAILQ_HEAD(, VLANClientState) non_vlan_clients;
> @@ -1080,6 +1082,53 @@ static const struct {
>   };
>   verify(ARRAY_SIZE(net_client_types) == NET_CLIENT_LAST);
>
> +
> +void do_info_netdev(Monitor *mon, QObject **data)
> +{
> +    QList *backends = qlist_new();
> +    int i, j;
> +
> +    for (i = 0; i<  ARRAY_SIZE(net_client_types) ; i++) {
> +	QObject *backend;
> +	QList *props = qlist_new();
> +
> +	if (i == NET_CLIENT_NIC ||
> +	    i == NET_CLIENT_DUMP||
> +	    i == NET_CLIENT_NONE)
> +	    continue;
> +
> +	for (j = 0 ; net_client_types[i].desc[j].name != NULL ; j++) {
> +	    const QemuOptDesc *desc = net_client_types[i].desc + j;
> +	    QObject *prop;
> +
> +	    if (strcmp(desc->name, "vlan") == 0)
> +		continue;
> +
> +	    if (desc->help) {
> +		prop = qobject_from_jsonf("{ 'name': %s, 'type': %s, 'help': %s }",
> +					  desc->name,
> +					  qemu_opt_type_to_string(desc->type),
> +					  desc->help);
> +	    } else {
> +		prop = qobject_from_jsonf("{ 'name': %s, 'type': %s }",
> +					  desc->name,
> +					  qemu_opt_type_to_string(desc->type));
> +	    }
> +
> +	    qlist_append_obj(props, prop);
> +	}
> +
> +	backend = qobject_from_jsonf("{ 'name': %s, 'props': %p }",
> +				     qemu_net_type_to_string(i),
> +				     props);
> +
> +	qlist_append_obj(backends, backend);
> +    }
> +
> +    *data = qobject_from_jsonf("{ 'backends': %p }", backends);
> +}
> +
> +
>   int net_client_init(Monitor *mon, QemuOpts *opts, int is_netdev)
>   {
>       const char *name;
> diff --git a/net.h b/net.h
> index b83f615..9c0e385 100644
> --- a/net.h
> +++ b/net.h
> @@ -167,6 +167,8 @@ void net_host_device_remove(Monitor *mon, const QDict *qdict);
>   int do_netdev_add(Monitor *mon, const QDict *qdict, QObject **ret_data);
>   int do_netdev_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
>
> +void do_info_netdev(Monitor *mon, QObject **data);
> +
>   #define DEFAULT_NETWORK_SCRIPT "/etc/qemu-ifup"
>   #define DEFAULT_NETWORK_DOWN_SCRIPT "/etc/qemu-ifdown"
>   #ifdef __sun__
> diff --git a/qemu-option.c b/qemu-option.c
> index bb9cc43..f132a9b 100644
> --- a/qemu-option.c
> +++ b/qemu-option.c
> @@ -32,6 +32,10 @@
>   #include "qemu-option.h"
>   #include "qerror.h"
>
> +QEMU_ENUM_IMPL(qemu_opt_type, QEMU_OPT_LAST,
> +	       "string", "bool", "number",
> +	       "size", "enum");
> +
>   /*
>    * Extracts the name of an option from the parameter string (p points at the
>    * first byte of the option name)
> diff --git a/qemu-option.h b/qemu-option.h
> index 3540a9b..9382cc3 100644
> --- a/qemu-option.h
> +++ b/qemu-option.h
> @@ -28,6 +28,7 @@
>
>   #include<stdint.h>
>   #include "qemu-queue.h"
> +#include "qemu-enum.h"
>   #include "qdict.h"
>
>   enum QEMUOptionParType {
> @@ -90,7 +91,10 @@ enum QemuOptType {
>       QEMU_OPT_NUMBER,      /* simple number                                        */
>       QEMU_OPT_SIZE,        /* size, accepts (K)ilo, (M)ega, (G)iga, (T)era postfix */
>       QEMU_OPT_ENUM,        /* int, from user string validated against an enum      */
> +
> +    QEMU_OPT_LAST,
>   };
> +QEMU_ENUM_DECL(qemu_opt_type);
>
>   typedef struct QemuOptDesc {
>       const char *name;
>