### What this PR does / why we need it?
- This PR adds the support for the KV connector interface in the V1
architecture, in the same way as vllm. Vllm-ascend currently lacks of
this support, required to support also layerwise management of KV
caches.
- The connector interface allows using external tools and integrate them
with vllm
### Notes:
We are aware of Issue #684 , however that issue does not modify the
attention classes as necessary to perform layerwise management of KV
caches required for connectors like LMCache.
The implementation of this PR ported the necessary code from the vanilla
vllm. The KV connector API is the same as vanilla vllm, supporting the
standard KV connector API.
EDIT: this PR was re-implementing part of the changes merged one hour
before this PR was made on the file model_runner_v1.py. I solved the
conflicts by removing any modification to the model_runner_v1 file,
which now are largely already merged in main. Now this PR is left for
the modifications to the attention_v1 file.
### Does this PR introduce _any_ user-facing change?
The PR does not modify current APIs, but it extends the behavior of
current worker runner and attention classes to save and load KV caches.
In absence of connectors, the behavior should stay untouched.
### How was this patch tested?
- No unit test implemented yet for the worker.
- Tested together with LMCache using
https://github.com/LMCache/LMCache/blob/dev/examples/kv_cache_reuse/local_backends/offload.py
with the following models:
1 Deepseek-R1-Distill-Qwen-1.5B
2 Qwen3-30B-A3B
3 Deepseek-v2-lite
4 Llama-3.1-8B
LMCache used in both layerwise and non-layerwise mode.
- Performed LMEval on LMCache integrated with vllm-ascend.
Results without LMCache on Qwen3-8B:
|Tasks|Version| Filter |n-shot| Metric | |Value | |Stderr|
|-----|------:|----------------|-----:|-----------|---|-----:|---|-----:|
|gsm8k| 3|flexible-extract| 5|exact_match|↑ |0.8400|± |0.0101|
| | |strict-match | 5|exact_match|↑ |0.8355|± |0.0102|
Results with LMCache Layerwise:
|Tasks|Version| Filter |n-shot| Metric | |Value | |Stderr|
|-----|------:|----------------|-----:|-----------|---|-----:|---|-----:|
|gsm8k| 3|flexible-extract| 5|exact_match|↑ |0.8385|± |0.0101|
| | |strict-match | 5|exact_match|↑ |0.8332|± |0.0103|
- vLLM version: v0.10.1.1
- vLLM main:
50fede6634
---------
Signed-off-by: marcobarlo <barlettamarco8@gmail.com>
Signed-off-by: marcobarlo <65128997+marcobarlo@users.noreply.github.com>
vLLM Ascend Plugin
| About Ascend | Documentation | #sig-ascend | Users Forum | Weekly Meeting |
English | 中文
Latest News 🔥
- [2025/09] We released the new official version v0.9.1! Please follow the official guide to start deploy large scale Expert Parallelism (EP) on Ascend.
- [2025/08] We hosted the vLLM Beijing Meetup with vLLM and Tencent! Please find the meetup slides here.
- [2025/06] User stories page is now live! It kicks off with LLaMA-Factory/verl//TRL/GPUStack to demonstrate how vLLM Ascend assists Ascend users in enhancing their experience across fine-tuning, evaluation, reinforcement learning (RL), and deployment scenarios.
- [2025/06] Contributors page is now live! All contributions deserve to be recorded, thanks for all contributors.
- [2025/05] We've released first official version v0.7.3! We collaborated with the vLLM community to publish a blog post sharing our practice: Introducing vLLM Hardware Plugin, Best Practice from Ascend NPU.
- [2025/03] We hosted the vLLM Beijing Meetup with vLLM team! Please find the meetup slides here.
- [2025/02] vLLM community officially created vllm-project/vllm-ascend repo for running vLLM seamlessly on the Ascend NPU.
- [2024/12] We are working with the vLLM community to support [RFC]: Hardware pluggable.
Overview
vLLM Ascend (vllm-ascend) is a community maintained hardware plugin for running vLLM seamlessly on the Ascend NPU.
It is the recommended approach for supporting the Ascend backend within the vLLM community. It adheres to the principles outlined in the [RFC]: Hardware pluggable, providing a hardware-pluggable interface that decouples the integration of the Ascend NPU with vLLM.
By using vLLM Ascend plugin, popular open-source models, including Transformer-like, Mixture-of-Expert, Embedding, Multi-modal LLMs can run seamlessly on the Ascend NPU.
Prerequisites
- Hardware: Atlas 800I A2 Inference series, Atlas A2 Training series, Atlas 800I A3 Inference series, Atlas A3 Training series, Atlas 300I Duo (Experimental)
- OS: Linux
- Software:
- Python >= 3.9, < 3.12
- CANN >= 8.2.rc1 (Ascend HDK version refers to here)
- PyTorch >= 2.7.1, torch-npu >= 2.7.1.dev20250724
- vLLM (the same version as vllm-ascend)
Getting Started
Please use the following recommended versions to get started quickly:
| Version | Release type | Doc |
|---|---|---|
| v0.10.1rc1 | Latest release candidate | QuickStart and Installation for more details |
| v0.9.1 | Latest stable version | QuickStart and Installation for more details |
Contributing
See CONTRIBUTING for more details, which is a step-by-step guide to help you set up development environment, build and test.
We welcome and value any contributions and collaborations:
- Please let us know if you encounter a bug by filing an issue
- Please use User forum for usage questions and help.
Branch
vllm-ascend has main branch and dev branch.
- main: main branch,corresponds to the vLLM main branch, and is continuously monitored for quality through Ascend CI.
- vX.Y.Z-dev: development branch, created with part of new releases of vLLM. For example,
v0.7.3-devis the dev branch for vLLMv0.7.3version.
Below is maintained branches:
| Branch | Status | Note |
|---|---|---|
| main | Maintained | CI commitment for vLLM main branch and vLLM 0.10.x branch |
| v0.7.1-dev | Unmaintained | Only doc fixed is allowed |
| v0.7.3-dev | Maintained | CI commitment for vLLM 0.7.3 version, only bug fix is allowed and no new release tag any more. |
| v0.9.1-dev | Maintained | CI commitment for vLLM 0.9.1 version |
| rfc/feature-name | Maintained | Feature branches for collaboration |
Please refer to Versioning policy for more details.
Weekly Meeting
- vLLM Ascend Weekly Meeting: https://tinyurl.com/vllm-ascend-meeting
- Wednesday, 15:00 - 16:00 (UTC+8, Convert to your timezone)
License
Apache License 2.0, as found in the LICENSE file.
