---
id: pr-vllm-40045
repo: vllm-project/vllm
pr: 40045
title: '[Attention] use diff kv backend for mimo v2 flash'
author: ZJY0516
date: '2026-04-24'
url: https://github.com/vllm-project/vllm/pull/40045
source_category: upstream-code
architectures:
- sm90
tags:
- attention_kv
- sm90
techniques:
- cache-policy
hardware_features:
- hopper
kernel_types:
- attention
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: e8ee2a78dbc08d398d5e798a149657b8aa821850
inclusion_reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.
changed_paths:
- docs/design/attention_backends.md
- tools/pre_commit/generate_attention_backend_docs.py
- vllm/model_executor/layers/attention/attention.py
- vllm/model_executor/models/mimo_v2_flash.py
- vllm/v1/attention/backends/fa_utils.py
- vllm/v1/attention/backends/flash_attn_diffkv.py
- vllm/v1/kv_cache_interface.py
- vllm/vllm_flash_attn/flash_attn_interface.py
artifact_dir: evidence/pull-bundles/vllm/gh-40045
head_ref_oid: f6429ed06a4bcd0a3a24749c29a93202830254e1
---
# [Attention] use diff kv backend for mimo v2 flash

- Repository: `vllm-project/vllm`
- PR: [40045](https://github.com/vllm-project/vllm/pull/40045)
- Decision: `Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.`
- Reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.

## Changed Paths

- `docs/design/attention_backends.md`
- `tools/pre_commit/generate_attention_backend_docs.py`
- `vllm/model_executor/layers/attention/attention.py`
- `vllm/model_executor/models/mimo_v2_flash.py`
- `vllm/v1/attention/backends/fa_utils.py`
- `vllm/v1/attention/backends/flash_attn_diffkv.py`
- `vllm/v1/kv_cache_interface.py`
- `vllm/vllm_flash_attn/flash_attn_interface.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-40045`
