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

[Markus Armbruster <armbru@redhat.com>]

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?

> 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?

> +# Since: 4.2
> +#
> +# Example:
> +#
> +# <- { "event": "FAILOVER_NEGOTIATED",
> +#      "data": "net1" }
> +#
> +##
> +{ 'event': 'FAILOVER_NEGOTIATED',
> +  'data': {'device-id': 'str'} }