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

[Jens Freimann <jfreimann@redhat.com>]

On Tue, Oct 29, 2019 at 06:41:58PM -0400, Michael S. Tsirkin wrote:
>On Fri, Oct 25, 2019 at 07:39:21PM +0200, Jens Freimann wrote:
>> 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
>
>And now I am confused.
>How is standby "the unplugged device"?
>Why not just say "the standby device"?

Yes, that's better. Do you want a patch on top?

diff --git a/qapi/net.json b/qapi/net.json
index ea6eeee4f7..0f225cb900 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -745,7 +745,7 @@
 # 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: QEMU device id of the standby device
 # Since: 4.2
 #
 # Example:


Signed-off-by: Jens Freimann <jfreimann@redhat.com>

regards,
Jens 

>
>-- 
>MST