07.09.2020, 15:40, "Markus Armbruster" <arm...@redhat.com>:
> Alexey Kirillov <lekir...@yandex-team.ru> writes:
>
>> Hi!
>>
>> 02.09.2020, 14:23, "Markus Armbruster" <arm...@redhat.com>:
>>> Alexey Kirillov <lekir...@yandex-team.ru> writes:
>>>
>>>> Add a qmp command that provides information about currently attached
>>>> backend network devices and their configuration.
>>>>
>>>> Signed-off-by: Alexey Kirillov <lekir...@yandex-team.ru>
>>>
>>> [...]
>>>> diff --git a/qapi/net.json b/qapi/net.json
>>>> index ddb113e5e5..c09322bb42 100644
>>>> --- a/qapi/net.json
>>>> +++ b/qapi/net.json
>>>> @@ -714,3 +714,71 @@
>>>> ##
>>>> { 'event': 'FAILOVER_NEGOTIATED',
>>>> 'data': {'device-id': 'str'} }
>>>> +
>>>> +##
>>>> +# @NetdevInfo:
>>>> +#
>>>> +# Configuration of a network backend device (netdev).
>>>> +#
>>>> +# @id: Device identifier.
>>>> +#
>>>> +# @type: Specify the driver used for interpreting remaining arguments.
>>>> +#
>>>> +# @peer-id: Connected frontend network device identifier.
>>>> +#
>>>> +# Since: 5.2
>>>> +##
>>>> +{ 'union': 'NetdevInfo',
>>>> + 'base': { 'id': 'str',
>>>> + 'type': 'NetClientDriver',
>>>> + '*peer-id': 'str' },
>>>> + 'discriminator': 'type',
>>>> + 'data': {
>>>> + 'user': 'NetdevUserOptions',
>>>> + 'tap': 'NetdevTapOptions',
>>>> + 'l2tpv3': 'NetdevL2TPv3Options',
>>>> + 'socket': 'NetdevSocketOptions',
>>>> + 'vde': 'NetdevVdeOptions',
>>>> + 'bridge': 'NetdevBridgeOptions',
>>>> + 'netmap': 'NetdevNetmapOptions',
>>>> + 'vhost-user': 'NetdevVhostUserOptions',
>>>> + 'vhost-vdpa': 'NetdevVhostVDPAOptions' } }
>>>
>>> This is union Netdev plus a common member @peer-id, less the variant
>>> members for NetClientDriver values 'nic' and 'hubport'.
>>>
>>> Can 'type: 'nic' and 'type': 'hubport' occur?
>>
>> No, it can't. We don't support NIC/hubport in query-netdevs, so we neither
>> create this
>> structure for them, nor store config.
>
> Same for 'none', I guess.
>
> As defined, NetdevInfo allows types 'none', 'nic', and 'hubport', it
> just has no variant members for them. The fact that they can't occur is
> not coded into the type, and therefore not visible in introspection.
>
> To make introspection more precise, we'd have to define a new enum type.
> How much that would complicate the C code is unclear.
>
> Do we need it to be more precise? Eric, got an opinion?
>
> Existing type Netdev has the same issue for 'none' and 'nic'. I guess
> this is so we can reuse the type for -net. Not sure that's a good idea,
> but not this patch's problem.
>
>>> What's the use case for @peer-id?
>>
>> Main reason is to provide information "is this backend connected to
>> frontend device".
>> User also may want to know which backend used for frontend device.
>>
>>> Assuming we want @peer-id: its documentation is too vague. Cases:
>>>
>>> * Not connected to a frontend: I guess @peer-id is absent then.
>>
>> Absolutely correct.
>>
>>> * Connected to a frontend
>>>
>>> - that has a qdev ID (the thing you set with -device id=...): I guess
>>> it's the qdev ID then.
>>
>> Correct.
>>
>>> - that doesn't have a qdev ID: anyone's guess.
>>
>> We use field "name" of structure NetClientState, so if there is no direct
>> ID setting,
>> there must be generated name (in format "model.id").
>
> Perhaps:
>
> # @peer-id: the connected network backend's name (absent if no
> # backend is connected)
Maybe you mean:
# @peer-id: The connected frontend network device name (absent if no frontend
# is connected).
In any case, thanks for pointing. I'll add this in the next patch version.
>>>> +
>>>> +##
>>>> +# @query-netdevs:
>>>> +#
>>>> +# Get a list of @NetdevInfo for all virtual network backend devices
>>>> (netdevs).
>>>> +#
>>>> +# Returns: a list of @NetdevInfo describing each netdev.
>>>> +#
>>>> +# Since: 5.2
>>>> +#
>>>> +# Example:
>>>> +#
>>>> +# -> { "execute": "query-netdevs" }
>>>> +# <- { "return": [
>>>> +# {
>>>> +# "ipv6": true,
>>>> +# "ipv4": true,
>>>> +# "host": "10.0.2.2",
>>>> +# "ipv6-dns": "fec0::3",
>>>> +# "ipv6-prefix": "fec0::",
>>>> +# "net": "10.0.2.0/255.255.255.0",
>>>> +# "ipv6-host": "fec0::2",
>>>> +# "type": "user",
>>>> +# "peer-id": "net0",
>>>> +# "dns": "10.0.2.3",
>>>> +# "hostfwd": [
>>>> +# {
>>>> +# "str": "tcp::20004-:22"
>>>> +# }
>>>> +# ],
>>>> +# "ipv6-prefixlen": 64,
>>>> +# "id": "netdev0",
>>>> +# "restrict": false
>>>> +# }
>>>> +# ]
>>>> +# }
>>>> +#
>>>> +##
>>>> +{ 'command': 'query-netdevs', 'returns': ['NetdevInfo'] }
--
Alexey Kirillov
Yandex.Cloud
