---
tags:
- kernels
library_name: kernels
license: apache-2.0
---

# conv2d-neuron-kernels

A NKI (Neuron Kernel Interface) `conv2d` kernel for AWS Trainium / Inferentia,
packaged for the HuggingFace `kernels` library + the `KernelConfig` API.

It replaces `torch.nn.Conv2d` with an implicit-GEMM NKI implementation that runs
on the NeuronCore Tensor Engine.

## Build variant

- `build/torch-neuron/` — pure-Python NKI kernel (compiled by `neuronx-cc` at
  load time). Requires the Neuron SDK (`nki`) to be installed in the runtime.

## Capabilities

- Arbitrary stride `(sH, sW)`
- Symmetric / asymmetric padding `(pH, pW)`
- Non-square kernels (`R x S`), `1x1`, `3x3`, `5x5`, ...
- Optional bias
- `bf16` and `fp32`

Constraints: `stride >= 1`, `dilation = 1`, `groups = 1`, padded plane
`Hp*Wp <= 32767` (single-tile). Correctness validated against
`torch.nn.functional.conv2d` (cosine = 1.0; fp32 max-abs ~1e-5).

## Usage

```python
from transformers import AutoModelForCausalLM, KernelConfig  # or any model with nn.Conv2d

kernel_config = KernelConfig({"Conv2d": "<owner>/conv2d-neuron-kernels:NeuronConv2d"})
model = AutoModelForCausalLM.from_pretrained(
    "<model-id>",
    use_kernels=True,
    kernel_config=kernel_config,
)
```

`Conv2d` (the key) is the original module class name that gets replaced.
`NeuronConv2d` (the value) is the `KernelName`; the repo also provides the
companion `NeuronConv2dLayout` that holds parameters and declares the
`[Cout,Cin,R,S] -> [Cin,R,S,Cout]` weight relayout via `conversion_mapping`.