They got seed money from NASA, and plenty of contracts, but not much that could be considered a "subsidy". At worst, they may have gotten some fat contracts as an investment by NASA, who desperately needed private companies to fill the LEO hole, and quick.

https://en.wikipedia.org/wiki/History_of_SpaceX#Funding

Supposedly, by 2012, about half of their funding had been government contracts that provided down payments, while the rest were private investments. A year later, they would be undercutting the costs of the Ariane 5 and Proton-M