---
id: pr-vllm-34580
repo: vllm-project/vllm
pr: 34580
title: Flashinfer cuDNN backend for Qwen3 VL ViT attention
author: maxyanghu
date: '2026-02-27'
url: https://github.com/vllm-project/vllm/pull/34580
source_category: upstream-code
architectures:
- sm100
tags: []
techniques: []
hardware_features: []
kernel_types: []
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: 9c3fe9936b929b5503d780bd4e8e3cd524de1c4e
inclusion_reason: defer
changed_paths:
- tests/kernels/attention/test_mha_attn.py
- vllm/model_executor/layers/attention/mm_encoder_attention.py
- vllm/model_executor/models/qwen2_5_vl.py
- vllm/model_executor/models/qwen3_vl.py
- vllm/platforms/cuda.py
- vllm/v1/attention/ops/vit_attn_wrappers.py
artifact_dir: evidence/pull-bundles/vllm/gh-34580
head_ref_oid: b4d09e94ce73c3c8b13e091a6d4eaf3888df7a36
---
# Flashinfer cuDNN backend for Qwen3 VL ViT attention

- Repository: `vllm-project/vllm`
- PR: [34580](https://github.com/vllm-project/vllm/pull/34580)
- Decision: `defer`
- Reason: defer

## Changed Paths

- `tests/kernels/attention/test_mha_attn.py`
- `vllm/model_executor/layers/attention/mm_encoder_attention.py`
- `vllm/model_executor/models/qwen2_5_vl.py`
- `vllm/model_executor/models/qwen3_vl.py`
- `vllm/platforms/cuda.py`
- `vllm/v1/attention/ops/vit_attn_wrappers.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-34580`
