### What this PR does / why we need it?
This pr is for https://github.com/vllm-project/vllm-ascend/issues/3241 ,
which is in-house solution for offloading KV cache data from the GPU
memory to other medium (in particular, CPU memory)。Previous solutions
required reliance on third-party components, which had issues with
compatibility between different versions.
### How was this patch tested?
use the following script for testing:
export CUDA_VISIBLE_DEVICES=0
export TP=1
export MODEL_PATH=/model/Qwen3-14B
export MODEL_NAME=Qwen3-14B
export PORT=10000
#export ASCEND_LAUNCH_BLOCKING=1
#export ASCEND_SLOG_PRINT_TO_STDOUT=1
python3 -m vllm.entrypoints.openai.api_server --host 0.0.0.0 --port
${PORT} --dtype bfloat16 --model ${MODEL_PATH} --served-model-name
${MODEL_NAME} --tensor-parallel-size ${TP} --gpu-memory-utilization 0.7
--max-model-len 32768 --trust-remote-code --disable-log-requests \
--block-size 128 \
--kv-transfer-config
'{"kv_connector":"OffloadingConnector","kv_role":"kv_both","kv_connector_extra_config":{"block_size":
128, "num_cpu_blocks": 1000, "spec_name":"NPUOffloadingSpec",
"spec_module_path": "vllm_ascend.kv_offload.npu"}}'
- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0
---------
Signed-off-by: HF-001 <1670186653@qq.com>
