vllm-project/vllm

[Feature]: Support DCP with FP8 KV Cache

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#32010 opened on Jan 9, 2026

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 (3 comments) (0 reactions) (0 assignees)Python (80,034 stars) (16,816 forks)batch import
feature requesthelp wanted

Description

🚀 The feature, motivation and pitch

DCP is great Fp8 kv cache is great We should support both at the same time:

(EngineCore_DP0 pid=2734260) ERROR 01-08 23:29:29 [core.py:900] RuntimeError: Worker failed with error 'DCP not support fp8 kvcache now.', please check the stack trace above for the root cause

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Contributor guide

Tech stack
python
Domain
backendmachine learning
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
familiarity with vllm's KV cacheunderstanding of DCP
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
15
Research direction
The error occurs in core.py:900. Investigate the DCP implementation (likely in vllm/distributed) and the FP8 KV cache code path (likely in vllm/kv cache). The goal is to enable DCP to handle FP8 KV cache, possibly by adding a check or conversion. Review existing tests for DCP and FP8 KV cache. Consider looking at PRs or issues related to DCP or FP8 for context.