Environment Variables

The following table documents commonly used environment variables. Some are consumed by the XMLIR or XPU runtime rather than by vLLM-Kunlun itself, so availability and exact behavior can depend on the installed runtime version.

Environment variable	Recommended value	Description
XPU_DUMMY_EVENT	unset	Uses real XPU events instead of dummy events for synchronization.
XPU_VISIBLE_DEVICES	0,1,2,3,4,5,6,7	Selects the physical XPU devices visible to the process. Adjust this list to the deployment.
XPU_USE_MOE_SORTED_THRES	512 (runtime default)	Legacy moe_ffn_block threshold on token rows (M): the sorted path is selected at or above this value. The current vLLM-Kunlun fused MoE path does not read this variable, so it should normally remain unset.
XFT_USE_FAST_SWIGLU	1	Enables the fast SwiGLU implementation in XFT operators.
XPU_USE_FAST_SWIGLU	1	Enables the fast SwiGLU implementation in Kunlun MoE operators.
XMLIR_CUDNN_ENABLED	1	Enables the XMLIR runtime’s cuDNN-compatible path. The exact implementation depends on the installed runtime.
XPU_USE_DEFAULT_CTX	1	Uses the XPU runtime’s default device context.
XMLIR_FORCE_USE_XPU_GRAPH	1	Routes CUDA Graph-compatible APIs to XPU Graph capture and replay.
VLLM_HOST_IP	$(hostname -i)	Advertises the host address to vLLM workers. On multi-NIC hosts, set one explicit address reachable by every worker.
XMLIR_ENABLE_MOCK_TORCH_COMPILE	false	Disables the default eager-only torch.compile mock so calls use the real compilation path.
XMLIR_DYNAMO_WORKAROUND	1	Registers F.linear as a custom operator to avoid Dynamo tracing issues on Kunlun XPU.
FUSED_QK_ROPE_OP	0	Controls the fused QK-Norm and RoPE implementation. Keep 0 unless a model-specific setup requires it.