---
id: pr-vllm-34732
repo: vllm-project/vllm
pr: 34732
title: '[Attention] Use FA4 for MLA prefill'
author: MatthewBonanni
date: '2026-03-12'
url: https://github.com/vllm-project/vllm/pull/34732
source_category: upstream-code
architectures:
- sm100
tags:
- attention
- mla
- prefill
techniques: []
hardware_features: []
kernel_types:
- attention
- mla
- prefill
languages:
- python
captured_at: '2026-04-27'
status: merged
merge_sha: f444c05c3267ed26f1fd52822d60479b81b2b829
inclusion_reason: kernel file changes
changed_paths:
- benchmarks/attention_benchmarks/benchmark.py
- benchmarks/attention_benchmarks/common.py
- benchmarks/attention_benchmarks/configs/mla_prefill.yaml
- benchmarks/attention_benchmarks/configs/mla_sparse_prefill.yaml
- benchmarks/attention_benchmarks/mla_runner.py
- cmake/external_projects/vllm_flash_attn.cmake
- vllm/config/attention.py
- vllm/model_executor/layers/attention/mla_attention.py
- vllm/v1/attention/backends/fa_utils.py
head_ref_oid: e177857b48d614a82792315eeaccd6382e16830e
artifact_dir: evidence/pull-bundles/vllm/gh-34732
---
# [Attention] Use FA4 for MLA prefill

- Repository: `vllm-project/vllm`
- PR: [34732](https://github.com/vllm-project/vllm/pull/34732)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `benchmarks/attention_benchmarks/benchmark.py`
- `benchmarks/attention_benchmarks/common.py`
- `benchmarks/attention_benchmarks/configs/mla_prefill.yaml`
- `benchmarks/attention_benchmarks/configs/mla_sparse_prefill.yaml`
- `benchmarks/attention_benchmarks/mla_runner.py`
- `cmake/external_projects/vllm_flash_attn.cmake`
- `vllm/config/attention.py`
- `vllm/model_executor/layers/attention/mla_attention.py`
- `vllm/v1/attention/backends/fa_utils.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-34732`
