Stross's "Missile Gap" is also deeply scary, and has an environment that might be entirely a highly advanced upload simulation.
https://web.archive.org/web/20140224051031/https://subterran...
https://web.archive.org/web/20140224051031/https://subterran...
You mean the redoubt at the end? Didn't they go through a portal to get there? Didn't seem to be an uploading machine. Also, why would they need fighter jets then? But it's an interesting thought...
It's not at all about uploading, but it is very much worth a read.