[Feature] Support HSDP for diffusion models (#1339)

Signed-off-by: gcanlin <canlinguosdu@gmail.com>
Co-authored-by: Hongsheng Liu <liuhongsheng4@huawei.com>

vllm_omni/diffusion/distributed/__init__.py

@@ -2,6 +2,15 @@
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 """Distributed utilities for vLLM-Omni diffusion models."""
 
+from vllm_omni.diffusion.distributed.hsdp import (
+    HSDPInferenceConfig,
+    apply_hsdp_to_model,
+)
+from vllm_omni.diffusion.distributed.parallel_state import (
+    get_fs_group,
+    get_fully_shard_rank,
+    get_fully_shard_world_size,
+)
 from vllm_omni.diffusion.distributed.sp_plan import (
     SequenceParallelConfig,
     SequenceParallelInput,
@@ -35,4 +44,10 @@ __all__ = [
     "sp_shard_with_padding",
     "ShardingValidator",
     "get_sharding_validator",
+    "HSDPInferenceConfig",
+    "apply_hsdp_to_model",
+    # FS (Fully Shard) utilities
+    "get_fs_group",
+    "get_fully_shard_rank",
+    "get_fully_shard_world_size",
 ]