xc-llm-ascend/docs/source/user_guide/configuration/additional_config.md

Additional Configuration

Additional configuration is a mechanism provided by vLLM to allow plugins to control internal behavior by themselves. VLLM Ascend uses this mechanism to make the project more flexible.

How to use

With either online mode or offline mode, users can use additional configuration. Take Qwen3 as an example:

Online mode:

vllm serve Qwen/Qwen3-8B --additional-config='{"config_key":"config_value"}'

Offline mode:

from vllm import LLM

LLM(model="Qwen/Qwen3-8B", additional_config={"config_key":"config_value"})

Configuration options

The following table lists additional configuration options available in vLLM Ascend:

Name	Type	Default	Description
xlite_graph_config	dict	{}	Configuration options for Xlite graph mode
weight_prefetch_config	dict	{}	Configuration options for weight prefetch
finegrained_tp_config	dict	{}	Configuration options for module tensor parallelism
ascend_compilation_config	dict	{}	Configuration options for ascend compilation
eplb_config	dict	{}	Configuration options for eplb
refresh	bool	false	Whether to refresh global Ascend configuration content. This is usually used by rlhf or ut/e2e test case.
dump_config_path	str	None	Configuration file path for msprobe dump(eager mode).
enable_async_exponential	bool	False	Whether to enable asynchronous exponential overlap. To enable asynchronous exponential, set this config to True.
enable_shared_expert_dp	bool	False	When the expert is shared in DP, it delivers better performance but consumes more memory. Currently only DeepSeek series models are supported.
multistream_overlap_shared_expert	bool	False	Whether to enable multi-stream shared expert. This option only takes effect on MoE models with shared experts.
multistream_overlap_gate	bool	False	Whether to enable multi-stream overlap gate. This option only takes effect on MoE models with shared experts.
recompute_scheduler_enable	bool	False	Whether to enable the recompute scheduler. Only valid in PD-disaggregated mode (kv_role is kv_producer or kv_consumer). Do not enable in PD-mixed mode (no kv_transfer_config, or kv_role is kv_both); startup will fail with a clear error.
enable_cpu_binding	bool	True	Whether to enable CPU binding. Only takes effect on ARM CPUs; A3 uses the global-slicing CPU allocation strategy and other device types use the topo-affinity CPU allocation strategy.
SLO_limits_for_dynamic_batch	int	-1	SLO limits for dynamic batch. This is new scheduler to support dynamic batch feature
enable_npugraph_ex	bool	False	Whether to enable npugraph_ex graph mode.
pa_shape_list	list	[]	The custom shape list of page attention ops.
enable_kv_nz	bool	False	Whether to enable KV cache NZ layout. This option only takes effects on models using MLA (e.g., DeepSeek).
layer_sharding	dict	{}	Configuration options for Layer Sharding Linear. In PD-disaggregated deployments, it is supported only on P nodes with kv_role="kv_producer".
enable_sparse_c8	bool	False	Whether to enable KV cache C8 in DSA models (e.g., DeepSeekV3.2 and GLM5). Not supported on A5 devices now
enable_mc2_hierarchy_comm	bool	False	Enable dispatch/combine op inter-node communication by ROCE.

The details of each configuration option are as follows:

xlite_graph_config

Name	Type	Default	Description
enabled	bool	False	Whether to enable Xlite graph mode. Currently only Llama, Qwen dense series models, and Qwen3-VL are supported.
full_mode	bool	False	Whether to enable Xlite for both the prefill and decode stages. By default, Xlite is only enabled for the decode stage.

weight_prefetch_config

Name	Type	Default	Description
enabled	bool	False	Whether to enable weight prefetch.
prefetch_ratio	dict	{"attn": {"qkv": 1.0, "o": 1.0}, "moe": {"gate_up": 0.8}, "mlp": { "gate_up": 1.0, "down": 1.0}}	Prefetch ratio of each weight.

finegrained_tp_config

Name	Type	Default	Description
lmhead_tensor_parallel_size	int	0	The custom tensor parallel size of lm_head.
oproj_tensor_parallel_size	int	0	The custom tensor parallel size of o_proj.
embedding_tensor_parallel_size	int	0	The custom tensor parallel size of embedding.
mlp_tensor_parallel_size	int	0	The custom tensor parallel size of mlp.

ascend_compilation_config

Name	Type	Default	Description
enable_npugraph_ex	bool	True	Whether to enable npugraph_ex backend.
enable_static_kernel	bool	False	Whether to enable static kernel. Suitable for scenarios where shape changes are minimal and some time is available for static kernel compilation.
fuse_norm_quant	bool	True	Whether to enable fuse_norm_quant pass.
fuse_qknorm_rope	bool	True	Whether to enable fuse_qknorm_rope pass. If Triton is not in the environment, set it to False.
fuse_allreduce_rms	bool	False	Whether to enable fuse_allreduce_rms pass. It's set to False because of conflict with SP.
fuse_muls_add	bool	True	Whether to enable fuse_muls_add pass.

eplb_config

Name	Type	Default	Description
dynamic_eplb	bool	False	Whether to enable dynamic EPLB.
expert_map_path	str	None	When using expert load balancing for an MoE model, an expert map path needs to be passed in.
expert_heat_collection_interval	int	400	Forward iterations when EPLB begins.
algorithm_execution_interval	int	30	The forward iterations when the EPLB worker will finish CPU tasks.
expert_map_record_path	str	None	Save the expert load calculation results to a new expert table in the specified directory.
num_redundant_experts	int	0	Specify redundant experts during initialization.

Example

An example of additional configuration is as follows:

{
    "weight_prefetch_config": {
        "enabled": True,
        "prefetch_ratio": {
            "attn": {
                "qkv": 1.0,
                "o": 1.0,
            },
            "moe": {
                "gate_up": 0.8
            },
            "mlp": {
                "gate_up": 1.0,
                "down": 1.0
            }
        },
    },
    "finegrained_tp_config": {
        "lmhead_tensor_parallel_size": 8,
        "oproj_tensor_parallel_size": 8,
        "embedding_tensor_parallel_size": 8,
        "mlp_tensor_parallel_size": 8,
    },
    "enable_kv_nz": False,
    "multistream_overlap_shared_expert": True,
    "refresh": False
}