I assume your xml file will have </events> and </eventdata>. If not it is not valid XML, but that can be fixed with a mutate+ gsub to append text to the message if needed.
Consume the entire XML as a single event using a file input and a multiline codec that never matches. For example
codec => multiline { pattern => "^Spalanzani" negate => true what => "previous" auto_flush_interval => 1 }
Then you can parse the XML and split on the event field
xml { source => "message" target => "theXML" store_xml => true }
split { field => "[theXML][events][0][event]" }
Then you just have mutate+rename all the fields to get them where you want them.