Interesting… I got rid of huge pages in my VM configuration (1 GB pages) and switched to host model. The VM has been up for more than 2 days so far. In comparison, it had crashed thrice in one night only on Monday.
I’d experiment further to find out which trick did it, but I need my system for more useful things at the moment than acting as a crash test dummy.
EDIT: Well, I spoke too soon. I left the Windows VM idle and was using the Ubuntu desktop host when random reset struck. 5 days is much better uptime than several hours, but far less than what I need the machine to be capable of.