Re: [PATCH v6 06/11] qapi: add failover negotiated event

[Jens Freimann <jfreimann@redhat.com>]

On Fri, Oct 25, 2019 at 04:03:54PM +0200, Markus Armbruster wrote:
>Bear with me, I know next to nothing about failover.
>
>Jens Freimann <jfreimann@redhat.com> writes:
>
>> This event is sent to let libvirt know that VIRTIO_NET_F_STANDBY feature
>> was enabled. The primary device this virtio-net device is associated
>> with, will now be hotplugged via qdev_device_add().
>
>Passive voice deftly avoids telling the reader who will do the
>hot-plugging.  Intentional?

Not really, it's in the comment to the event. The hotplug will be
 done by the virtio-net device code that activates the feature, in
virtio_net_set_features().

>
>> Signed-off-by: Jens Freimann <jfreimann@redhat.com>
>> Acked-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>>  qapi/net.json | 19 +++++++++++++++++++
>>  1 file changed, 19 insertions(+)
>>
>> diff --git a/qapi/net.json b/qapi/net.json
>> index 728990f4fb..ea6eeee4f7 100644
>> --- a/qapi/net.json
>> +++ b/qapi/net.json
>> @@ -737,3 +737,22 @@
>>  ##
>>  { 'command': 'announce-self', 'boxed': true,
>>    'data' : 'AnnounceParameters'}
>> +
>> +##
>> +# @FAILOVER_NEGOTIATED:
>> +#
>> +# Emitted when VIRTIO_NET_F_STANDBY was enabled during feature negotiation.
>> +# Failover primary devices which were hidden (not hotplugged when requested)
>> +# before will now be hotplugged by the virtio-net standby device.
>> +#
>> +# device-id: QEMU device id of the unplugged device
>
>@device-id is new since v5.
>
>A quick skim of
>https://www.kernel.org/doc/html/latest/networking/net_failover.html
>tells me there are three devices involved: master, primary slave,
>standby slave.  Which one is @device-id?  Or am I confused?

Yes, the device-id is new and it's the device-id of the standby (i.e.
virtio-net) device.

regards,
Jens