Please list the IDs of the events happened on all the vivo devices.
IDs of the events refers to event_id; vivo devices refers to phone_brand = 'vivo';
SELECT T2.event_id FROM phone_brand_device_model2 AS T1 INNER JOIN events AS T2 ON T2.device_id = T1.device_id WHERE T1.phone_brand = 'vivo'