Re: [Qemu-devel] [PATCH 11/19] Add a query-devices command to QMP

[Anthony Liguori <anthony@codemonkey.ws>]

On 06/07/2010 09:42 AM, Daniel P. Berrange wrote:
> Adds a command to QMP called 'query-devices' to allow for discovery
> of all devices known to the QEMU binary. THis is inteded to replace
> use of the '-device ?' and '-device devtype,?' command line args
>
> The data format is designed to allow easy extension to support more
> data:
>    

query-qdm?

Regards,

Anthony Liguori

>      [
>          {
>              "name": "virtio-9p-pci",
>              "creatable": true,
>              "bus": "PCI",
>              "props": [
>                  {
>                      "name": "indirect_desc",
>                      "type": "bit",
>                      "info": "on/off"
>                  },
>                  {
>                      "name": "mount_tag",
>                      "type": "string",
>                      "info": "string"
>                  },
>                  {
>                      "name": "fsdev",
>                      "type": "string",
>                      "info": "string"
>                  }
>              ]
>          },
>          {
>              "name": "virtio-balloon-pci",
>              "creatable": true,
>              "bus": "PCI",
>              "props": [
>                  {
>                      "name": "indirect_desc",
>                      "type": "bit",
>                      "info": "on/off"
>                  }
>              ]
>          },
>          ...
>      ]
>
> No legacy readline monitor output is provided.
>
> Signed-off-by: Daniel P. Berrange<berrange@redhat.com>
> ---
>   hw/qdev.c |  146 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   hw/qdev.h |    2 +
>   monitor.c |    8 +++
>   3 files changed, 156 insertions(+), 0 deletions(-)
>
> diff --git a/hw/qdev.c b/hw/qdev.c
> index 1186dfa..0a10c3c 100644
> --- a/hw/qdev.c
> +++ b/hw/qdev.c
> @@ -29,6 +29,7 @@
>   #include "qdev.h"
>   #include "sysemu.h"
>   #include "monitor.h"
> +#include "qjson.h"
>
>   static int qdev_hotplug = 0;
>
> @@ -810,3 +811,148 @@ int do_device_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
>       }
>       return qdev_unplug(dev);
>   }
> +
> +static const char *qdev_property_type_to_string(int type) {
> +    switch (type) {
> +    case PROP_TYPE_UNSPEC:
> +	return "unknown";
> +    case PROP_TYPE_UINT8:
> +	return "uint8";
> +    case PROP_TYPE_UINT16:
> +	return "uint16";
> +    case PROP_TYPE_UINT32:
> +	return "uint32";
> +    case PROP_TYPE_INT32:
> +	return "int32";
> +    case PROP_TYPE_UINT64:
> +	return "uint64";
> +    case PROP_TYPE_TADDR:
> +	return "taddr";
> +    case PROP_TYPE_MACADDR:
> +	return "macaddr";
> +    case PROP_TYPE_DRIVE:
> +	return "drive";
> +    case PROP_TYPE_CHR:
> +	return "chr";
> +    case PROP_TYPE_STRING:
> +	return "string";
> +    case PROP_TYPE_NETDEV:
> +	return "netdev";
> +    case PROP_TYPE_VLAN:
> +	return "vlan";
> +    case PROP_TYPE_PTR:
> +	return "pointer";
> +    case PROP_TYPE_BIT:
> +	return "bit";
> +    }
> +    return NULL;
> +}
> +
> +
> +/*
> + * Describe capabilities of all devices registered with qdev
> + *
> + * The returned output is a QList, each element is a QDict
> + * describing a single device type. The valid keys for the
> + * device dictionary are
> + *
> + *  - "name": the short name of the device
> + *  - "bus": the name of the bus type for the device
> + *  - "alias": an alias by which the device is also known (optional)
> + *  - "description": a long description the device (optional)
> + *  - "props": a list of device properties
> + *  - "creatable": whether this device can be created on command line
> + *
> + * The 'props' list is a QList, with each element being a
> + * QDict describing a single property of the device. The
> + * valid property keys are
> + *
> + *  - "name": the short name of the property
> + *  - "info": short description of the property
> + *  - "type": the data type of the property value
> + *
> + * An example:
> + *
> + *   [
> + *       {
> + *           "name": "virtio-9p-pci",
> + *           "creatable": true,
> + *           "bus": "PCI",
> + *           "props": [
> + *               {
> + *                   "name": "indirect_desc",
> + *                   "type": "bit",
> + *                   "info": "on/off"
> + *               },
> + *               {
> + *                   "name": "mount_tag",
> + *                   "type": "string",
> + *                   "info": "string"
> + *               },
> + *               {
> + *                   "name": "fsdev",
> + *                   "type": "string",
> + *                   "info": "string"
> + *               }
> + *           ]
> + *       },
> + *       {
> + *           "name": "virtio-balloon-pci",
> + *           "creatable": true,
> + *           "bus": "PCI",
> + *           "props": [
> + *               {
> + *                   "name": "indirect_desc",
> + *                   "type": "bit",
> + *                   "info": "on/off"
> + *               }
> + *           ]
> + *       },
> + *       ....
> + *   ]
> + */
> +void do_info_devices(Monitor *mon, QObject **data)
> +{
> +    DeviceInfo *info;
> +    QList *devs = qlist_new();
> +
> +    for (info = device_info_list; info != NULL; info = info->next) {
> +	QObject *dev;
> +	QList *props = qlist_new();
> +	Property *prop;
> +
> +	for (prop = info->props; prop&&  prop->name; prop++) {
> +	    QObject *entry;
> +	    /*
> +	     * TODO Properties without a parser are just for dirty hacks.
> +	     * qdev_prop_ptr is the only such PropertyInfo.  It's marked
> +	     * for removal.  This conditional should be removed along with
> +	     * it.
> +	     */
> +	    if (!prop->info->parse) {
> +		continue;           /* no way to set it, don't show */
> +	    }
> +
> +	    const char *type = qdev_property_type_to_string(prop->info->type);
> +
> +	    entry = qobject_from_jsonf("{ 'name': %s, 'info': %s, 'type': %s }",
> +				       prop->name, prop->info->name, type);
> +
> +	    qlist_append_obj(props, entry);
> +	}
> +
> +	dev = qobject_from_jsonf("{ 'name': %s, 'bus': %s, 'props': %p, 'creatable': %i }",
> +				 info->name,
> +				 info->bus_info->name,
> +				 props,
> +				 info->no_user ? 0 : 1);
> +	if (info->alias)
> +	    qdict_put_obj((QDict*)dev, "alias", QOBJECT(qstring_from_str(info->alias)));
> +	if (info->desc)
> +	    qdict_put_obj((QDict*)dev, "description", QOBJECT(qstring_from_str(info->desc)));
> +
> +	qlist_append_obj(devs, dev);
> +    }
> +
> +    *data = QOBJECT(devs);
> +}
> diff --git a/hw/qdev.h b/hw/qdev.h
> index a44060e..fe6f981 100644
> --- a/hw/qdev.h
> +++ b/hw/qdev.h
> @@ -280,6 +280,8 @@ void qdev_prop_set_defaults(DeviceState *dev, Property *props);
>   void qdev_prop_register_global_list(GlobalProperty *props);
>   void qdev_prop_set_globals(DeviceState *dev);
>
> +void do_info_devices(Monitor *mon, QObject **data);
> +
>   /* This is a nasty hack to allow passing a NULL bus to qdev_create.  */
>   extern struct BusInfo system_bus_info;
>
> diff --git a/monitor.c b/monitor.c
> index b6aa2b4..13f70a0 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -2458,6 +2458,14 @@ static const mon_cmd_t info_cmds[] = {
>           .mhandler.info_new = do_info_machines,
>       },
>       {
> +        .name       = "devices",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "show the registered QDev devices",
> +        .user_print = monitor_user_noop,
> +        .mhandler.info_new = do_info_devices,
> +    },
> +    {
>           .name       = "commands",
>           .args_type  = "",
>           .params     = "",
>