This anon recently had cause to rewatch 'Where Eagle Dare'. The plot of the film is to uncover the names of the German undercover agent(s) operating high up within the British government.

Here's a link to a scene with Richard Burton trying to contact home, using the code: 'Broadsword calling Danny Boy'. Skip to 2:35:

https://www.youtube.com/watch?v=CdaeBiF__u4

John Smith (Richard Burton) when asked if the mission has been successful, says: "We have it. We have it all."

Knowing Q's liking of movie quotes, this suggests that the phrase 'We have it all' might have to do with knowing the identities of enemy sleeper agents within the government and armed forces. What think you?