Re: [PATCH v5 18/18] qapi: introduce DEVICE_ON event

[Vladimir Sementsov-Ogievskiy]

On 02.03.23 11:44, Michael S. Tsirkin wrote:
> On Thu, Feb 16, 2023 at 09:03:56PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> > We have DEVICE_DELETED event, that signals that device_del command is
> > actually completed. But we don't have a counter-part for device_add.
> > Still it's sensible for SHPC and PCIe-native hotplug, as there are time
> > when the device in some intermediate state. Let's add an event that say
> > that the device is finally powered on, power indicator is on and
> > everything is OK for next manipulation on that device.
> >
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> > ---
> >   qapi/qdev.json | 10 ++++++++++
> >   hw/pci/pcie.c  | 14 ++++++++++++++
> >   hw/pci/shpc.c  | 12 ++++++++++++
> >   3 files changed, 36 insertions(+)
> >
> > diff --git a/qapi/qdev.json b/qapi/qdev.json
> > index 6f2d8d6647..116a8a7de8 100644
> > --- a/qapi/qdev.json
> > +++ b/qapi/qdev.json
> > @@ -348,3 +348,13 @@
> >   { 'command': 'query-hotplug',
> >     'data': { 'id': 'str' },
> >     'returns': 'HotplugInfo' }
> > +
> > +##
> > +# @DEVICE_ON:
> > +#
> > +# Emitted whenever the device insertion completion is acknowledged by the 
> > guest.
> > +# For now only emitted for SHPC and PCIe-native hotplug.
> > +#
> > +# Since: 8.0
> > +##
> > +{ 'event': 'DEVICE_ON', 'data': 'DeviceAndPath' }
>
> Same as any event, this has to be accompanied by a query.
> Which query returns the "ON" status?

Hmm. Seems correct to add "ON" status into "hostplug state", to be returned by 
query-hotplug. And then, its change should be reported by HOTPLUG_STATE, and separate DEVICE_ON is 
not needed.

--
Best regards,
Vladimir