Not stupid at all! 
Right now we support the ONNXIFI interface 14 which allows PyTorch/Caffe2 to use Glow as an execution backend. Through ONNXIFI (technically FOXI as noted there) the model is passed as an ONNX or C2 proto to Glow, loaded/compiled/quantized/etc., and run on one of our backends.
We also have a very basic PR up here 10 (has not yet landed) that creates an actual Glow backend for PyTorch, which goes more directly from PyTorch IR to Glow.