---
id: pr-vllm-21590
repo: vllm-project/vllm
pr: 21590
title: Override attention metadata for fast prefill in some KV sharing setups
author: sarckk
date: '2025-07-30'
url: https://github.com/vllm-project/vllm/pull/21590
source_category: upstream-code
architectures:
- sm100
tags:
- attention
- gemm
- prefill
techniques: []
hardware_features: []
kernel_types:
- attention
- gemm
- prefill
languages:
- python
captured_at: '2026-04-27'
status: merged
merge_sha: ad510309ee10e5182b99ee94ddc5ace716c65050
inclusion_reason: kernel file changes
changed_paths:
- tests/v1/e2e/test_kv_sharing_fast_prefill.py
- vllm/config.py
- vllm/engine/arg_utils.py
- vllm/model_executor/models/gemma3n.py
- vllm/v1/attention/backends/utils.py
- vllm/v1/worker/gpu_model_runner.py
head_ref_oid: ba83304143428b5ee18994c923a31a7eecf71699
artifact_dir: evidence/pull-bundles/vllm/gh-21590
---
# Override attention metadata for fast prefill in some KV sharing setups

- Repository: `vllm-project/vllm`
- PR: [21590](https://github.com/vllm-project/vllm/pull/21590)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `tests/v1/e2e/test_kv_sharing_fast_prefill.py`
- `vllm/config.py`
- `vllm/engine/arg_utils.py`
- `vllm/model_executor/models/gemma3n.py`
- `vllm/v1/attention/backends/utils.py`
- `vllm/v1/worker/gpu_model_runner.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-21590`
