Laurent Vivier <lviv...@redhat.com> writes:
> On 14/02/2025 11:06, Markus Armbruster wrote:
>> Laurent Vivier <lviv...@redhat.com> writes:
>>
>>> The netdev reports NETDEV_VHOST_USER_CONNECTED event when
>>> the chardev is connected, and NETDEV_VHOST_USER_DISCONNECTED
>>> when it is disconnected.
>>>
>>> The NETDEV_VHOST_USER_CONNECTED event includes the ChardevInfo
>>> (label, filename and frontend_open).
>>>
>>> This allows a system manager like libvirt to detect when the server
>>> fails.
>>>
>>> For instance with passt:
>>>
>>> { 'execute': 'qmp_capabilities' }
>>> { "return": { } }
>>>
>>> [killing passt here]
>>>
>>> { "timestamp": { "seconds": 1739517243, "microseconds": 115081 },
>>> "event": "NETDEV_VHOST_USER_DISCONNECTED",
>>> "data": { "netdev-id": "netdev0" } }
>>>
>>> [automatic reconnection with reconnect-ms]
>>>
>>> { "timestamp": { "seconds": 1739517290, "microseconds": 343777 },
>>> "event": "NETDEV_VHOST_USER_CONNECTED",
>>> "data": { "netdev-id": "netdev0",
>>> "info": { "frontend-open": true,
>>> "filename": "unix:",
>>> "label": "chr0" } } }
>>>
>>> Signed-off-by: Laurent Vivier <lviv...@redhat.com>
>>
>> Standard question for events: if a management application misses an
>> event, say because it restarts and reconnects, is there a way to obtain
>> the missed information with a query command?
>
> query-chardev could help but it doesn't provide the netdev id.
>
> in HMP, "info network" has the information, but for QMP we had a try with a
> query-netdev in the past but the series has been reverted.
>
> f9bb0c1f9862 ("Revert "qapi: net: Add query-netdev command"")
> d32ad10a14d4 ("qapi: net: Add query-netdev command")
Hmm. Can management applications use these events without a matching
query?
