The error seems to be raised in self.conv1, which should already be in cuda:0 as well as its input x.
Could you check the device of all internal parameters of this layer and also of self.cbr_unit, as this modules is undefined in your code?
Also, I assume you are not wrapping your model into nn.DataParallel, since you are using a model parallel approach? In case you do, this could explain the error, since the model would be cloned to each device, while you are forcing the input to be on GPU0 in the forward pass.