Quantization: support FP4 quantized models on AMD CDNA2/CDNA3 GPUs #22527
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Code Review
This pull request adds support for FP4 quantized models on AMD GPUs using the petit-kernel. The changes look mostly good, with new quantization configurations and utility functions. However, I found a critical issue in the PetitNvFp4Config.from_config method where it uses direct dictionary access for optional keys, which can lead to a KeyError and crash the application if the keys are not present in the configuration file. I've suggested a more robust implementation for this method to handle missing keys gracefully.
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Signed-off-by: feng <fengli1702@gmail.com>
Signed-off-by: feng <fengli1702@gmail.com>
Signed-off-by: feng <fengli1702@gmail.com>
Signed-off-by: feng <fengli1702@gmail.com>
Signed-off-by: Michael Goin <mgoin64@gmail.com>
…llm-project#22527) Signed-off-by: feng <fengli1702@gmail.com> Signed-off-by: Michael Goin <mgoin64@gmail.com> Co-authored-by: Michael Goin <mgoin64@gmail.com>
…llm-project#22527) Signed-off-by: feng <fengli1702@gmail.com> Signed-off-by: Michael Goin <mgoin64@gmail.com> Co-authored-by: Michael Goin <mgoin64@gmail.com> Signed-off-by: Xiao Yu <xiao.yu@amd.com>
…llm-project#22527) Signed-off-by: feng <fengli1702@gmail.com> Signed-off-by: Michael Goin <mgoin64@gmail.com> Co-authored-by: Michael Goin <mgoin64@gmail.com>
…llm-project#22527) Signed-off-by: feng <fengli1702@gmail.com> Signed-off-by: Michael Goin <mgoin64@gmail.com> Co-authored-by: Michael Goin <mgoin64@gmail.com>
…llm-project#22527) Signed-off-by: feng <fengli1702@gmail.com> Signed-off-by: Michael Goin <mgoin64@gmail.com> Co-authored-by: Michael Goin <mgoin64@gmail.com>
…llm-project#22527) Signed-off-by: feng <fengli1702@gmail.com> Signed-off-by: Michael Goin <mgoin64@gmail.com> Co-authored-by: Michael Goin <mgoin64@gmail.com> Signed-off-by: Ekagra Ranjan <3116519+ekagra-ranjan@users.noreply.github.com>
…llm-project#22527) Signed-off-by: feng <fengli1702@gmail.com> Signed-off-by: Michael Goin <mgoin64@gmail.com> Co-authored-by: Michael Goin <mgoin64@gmail.com>
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Essential Elements of an Effective PR Description Checklist
supported_models.mdandexamplesfor a new model.Purpose
Add support for running FP4 quantized models on AMD CDNA2 / CDNA3 GPUs via a new quantization backend petit_nvfp4. This enables vLLM to serve models such as Llama-3.1 / Llama-3.3
Test Plan
Verified that ROCm backend without --quantization still runs normally, and automatically selects the petit-kernel FP4 path when loading FP4 quantized models.
Installed optional dependencies via:
Ran test with:
Confirmed that the FP4 path (petit-kernel) is selected automatically and outputs are generated successfully.
Test Result
Functional test passed: FP4 quantized models load and run inference successfully on ROCm (MI250/MI300 test nodes) without specifying --quantization.
Non-quantized ROCm inference path unaffected.
Verified via log output that petit-kernel module is loaded when using FP4 models.
(Optional) Documentation Update
Added fp4 extras in setup.py for optional dependency installation.