How should I modify the code to implement Sequence Parallel for training Multimodal models?

Hi! I'm using XTuner to finetune Multimodal LLMs on long-context data, so I need to use sequence parallel to avoid OOM. I read the code about sequence parallelism, but I have poor knowledge about these techniques.

I know I need to implement dispatched forward functions for the corresponding modules like `xtuner/model/modules/dispatch/qwen2.py`, and register these functions in corresponding DISPATCH_MAPPING in `xtuner/model/modules/dispatch/__init__.py`. But I can't figure out whether I need to change **other** parts of the code. Multimodal LLMs introduces an additional stage of scattering image features into corresponding positions in the input sequence, does this process affect Sequence Parallel?

I would appreciate it if you could offer some help! Thank you!