Re: [PATCH v4 16/16] qapi: introduce DEVICE_ON event

[Markus Armbruster]

Philippe Mathieu-Daudé <philmd@linaro.org> writes:

> On 13/2/23 15:01, 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 | 13 +++++++++++++
>>   hw/pci/pcie.c  | 13 +++++++++++++
>>   hw/pci/shpc.c  | 12 ++++++++++++
>>   3 files changed, 38 insertions(+)
>> diff --git a/qapi/qdev.json b/qapi/qdev.json
>> index b6ad311dd4..2143bb2792 100644
>> --- a/qapi/qdev.json
>> +++ b/qapi/qdev.json
>> @@ -341,3 +341,16 @@
>>   { '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.
>> +#
>> +# @path: the hotplugged device's QOM path
>> +#
>> +# Since: 8.0
>> +##
>> +{ 'event': 'DEVICE_ON',
>> +  'data': { 'path': 'str' } }
>
> Could 'qom-path' or 'canonical-path' be more meaningful here?

@qom-path would be clearer, no doubt.  But @path is consistent with the
closely related DEVICE_DELETED event.

>> @@ -816,6 +823,12 @@ void pcie_cap_slot_write_config(PCIDevice *dev,
>>           qdev_hotplug_state_event(DEVICE(dev), NULL, child_dev, 
>> &changed_state);
>>       }
>>   +    if ((sltsta & PCI_EXP_SLTSTA_PDS) && pcie_sltctl_powered_on(val) &&
>> +        !pcie_sltctl_powered_on(old_slt_ctl) && child_dev)
>> +    {
>> +        qapi_event_send_device_on(child_dev->canonical_path);
>> +    }