[Feature]: Add vae-patch-parallel CLI argument in online serving (#1716)

Signed-off-by: Didan Deng <33117903+wtomin@users.noreply.github.com>

docs/user_guide/examples/online_serving/text_to_image.md

@@ -23,6 +23,29 @@ Or use the startup script:
 bash run_server.sh
 ```
 
+### Start with Parallelism Acceleration
+
+Enable Tensor Parallelism and VAE Patch Parallelism for faster inference:
+
+```bash
+# With Tensor Parallelism (requires >= 2 GPUs)
+vllm serve Qwen/Qwen-Image --omni --port 8091 --tensor-parallel-size 2
+
+# With Tensor Parallelism and VAE Patch Parallelism (requires >= 2 GPUs)
+vllm serve Qwen/Qwen-Image --omni --port 8091 --tensor-parallel-size 2 --vae-patch-parallel-size 2 --vae-use-tiling
+
+# With Sequence Parallelism (Ulysses-SP, requires >= 2 GPUs)
+vllm serve Qwen/Qwen-Image --omni --port 8091 --usp 2
+
+# With Ring-Attention (requires >= 2 GPUs)
+vllm serve Qwen/Qwen-Image --omni --port 8091 --ring 2
+
+# Combined: Ulysses + Ring (requires >= 4 GPUs)
+vllm serve Qwen/Qwen-Image --omni --port 8091 --usp 2 --ring 2
+```
+
+For more details on parallelism acceleration, see the [Parallelism Acceleration Guide](../../diffusion/parallelism_acceleration.md).
+
 ## API Calls
 
 ### Method 1: Using curl

vllm_omni/entrypoints/async_omni.py

@@ -141,6 +141,7 @@ class AsyncOmni(OmniBase):
             sequence_parallel_size = kwargs.get("sequence_parallel_size")
             tensor_parallel_size = kwargs.get("tensor_parallel_size") or 1
             cfg_parallel_size = kwargs.get("cfg_parallel_size") or 1
+            vae_patch_parallel_size = kwargs.get("vae_patch_parallel_size") or 1
             use_hsdp = kwargs.get("use_hsdp", False)
             hsdp_shard_size = kwargs.get("hsdp_shard_size", -1)
             hsdp_replicate_size = kwargs.get("hsdp_replicate_size", 1)
@@ -165,6 +166,7 @@ class AsyncOmni(OmniBase):
                 ulysses_degree=ulysses_degree,
                 ring_degree=ring_degree,
                 cfg_parallel_size=cfg_parallel_size,
+                vae_patch_parallel_size=vae_patch_parallel_size,
                 use_hsdp=use_hsdp,
                 hsdp_shard_size=hsdp_shard_size,
                 hsdp_replicate_size=hsdp_replicate_size,

vllm_omni/entrypoints/cli/serve.py

@@ -219,6 +219,7 @@ class OmniServeCommand(CLISubcommand):
         )
         omni_config_group.add_argument(
             "--ring",
+            "--ring-degree",
             dest="ring_degree",
             type=int,
             default=None,
@@ -335,6 +336,14 @@ class OmniServeCommand(CLISubcommand):
             help="Number of devices for CFG parallel computation for diffusion models. "
             "Equivalent to setting DiffusionParallelConfig.cfg_parallel_size.",
         )
+        omni_config_group.add_argument(
+            "--vae-patch-parallel-size",
+            type=int,
+            default=1,
+            help="VAE Patch Parallelism degree for diffusion models. "
+            "Distributes VAE decode workload across multiple ranks by splitting the latent spatially. "
+            "Equivalent to setting DiffusionParallelConfig.vae_patch_parallel_size.",
+        )
 
         # Default sampling parameters
         omni_config_group.add_argument(