### What does this PR do?
#### Summary
Redesigns the `quant_cfg` configuration format in ModelOpt's PyTorch
quantization stack, replacing the previous dict-based format with an
**ordered list of typed `QuantizerCfgEntry` dicts**.
##### Motivation
The old `quant_cfg` dict had several pain points:
- **Ambiguous precedence**: no explicit way to reason about which entry
wins when multiple keys match a quantizer
- **Mixed key namespaces**: wildcard paths and PyTorch class names lived
in the same dict level, requiring ad-hoc dispatch
- **Magic `"default"` key**: an implicit, undocumented catch-all that
was easy to misuse
- **Poor composability**: merging two configs required dict updates that
silently discarded keys
- **No YAML round-trip fidelity**: the nested structure couldn't be
expressed cleanly in YAML
##### New format
`quant_cfg` is now an ordered list of `QuantizerCfgEntry` TypedDicts.
Each entry has:
- `quantizer_name` *(required)*: `fnmatch` wildcard matched against
quantizer module names
- `cfg` *(optional)*: dict (or list of dicts) of
`QuantizerAttributeConfig` fields
- `enable` *(optional)*: toggles quantizer on/off independently of `cfg`
- `parent_class` *(optional)*: restricts match to quantizers whose
parent module is of the given PyTorch class (e.g. `"nn.BatchNorm2d"`)
Entries are applied in list order; later entries override earlier ones.
The canonical pattern is deny-all first (`_base_disable_all`), then
selectively re-enable and configure, then apply standard exclusions
(`_default_disabled_quantizer_cfg`).
##### Changes
**Core library (`modelopt/torch/quantization/`)**
- **`config.py`**:
- Added `QuantizerCfgEntry` TypedDict (line 163) and
`find_quant_cfg_entry_by_path()` helper for exact-match lookup of
entries by path.
- Added `normalize_quant_cfg_list()` (line 1539) that converts legacy
formats (flat dict, single-key dicts, `nn.*`-scoped dicts, `"default"`
key) to canonical `QuantizerCfgEntry` lists. After normalization every
entry is guaranteed to have explicit `quantizer_name`, `enable`, and
`cfg` keys.
- Converted `_default_disabled_quantizer_cfg` and
`_mamba_moe_disabled_quantizer_cfg` from dicts to lists of
`QuantizerCfgEntry`.
- Added `_base_disable_all` (line 205): canonical deny-all entry
(`[{"quantizer_name": "*", "enable": False}]`).
- Converted all ~30 built-in config constants (`INT8_DEFAULT_CFG`,
`FP8_DEFAULT_CFG`, `NVFP4_DEFAULT_CFG`, etc.) to list format using
`*_base_disable_all` and `*_default_disabled_quantizer_cfg` unpacking.
- KV-cache configs (`FP8_KV_CFG`, `NVFP4_KV_CFG`, etc.) are now minimal
lists designed to be concatenated with a primary config — they
intentionally omit `_base_disable_all` and `"algorithm"`.
- Added two `QuantizeConfig` Pydantic field validators: a
`mode="before"` validator that calls `normalize_quant_cfg_list()`, and a
`mode="after"` validator that validates `cfg` dicts against
`QuantizerAttributeConfig`.
- Updated `need_calibration()` to iterate the normalized list instead of
the old dict.
- Changed `QuantizeQuantCfgType` alias from `dict[str | Callable, ...]`
to `list[QuantizerCfgEntry]`.
- **`conversion.py`**:
- Rewrote `set_quantizer_by_cfg()` (line 217) to iterate the list
directly. Each entry's `parent_class` is resolved via
`QuantModuleRegistry[parent_class_name]` (the existing `_DMRegistryCls`
registry).
- Added `set_quantizer_attributes_full()` (line 314): full replacement
of quantizer attributes from a `QuantizerAttributeConfig`. Unspecified
fields revert to defaults, enforcing entry atomicity. Can also upgrade
`TensorQuantizer` → `SequentialQuantizer` or downgrade the reverse.
- Added `set_quantizer_attributes_partial()` (line 384): merges a
partial `dict` of attributes into existing quantizer state. Does NOT
change quantizer structure. Used for enable-only entries.
- Added `set_quantizer_by_cfg_context()` context manager (line 447) that
temporarily applies a `quant_cfg` list and restores original quantizer
state on exit.
- Deprecated `set_quantizer_attribute()` (line 525) with a
`DeprecationWarning` pointing to the new functions.
- **`tensor_quantizer.py`**:
- `TensorQuantizer.set_from_attribute_config()`: narrowed type hint from
`dict` to `dict[str, Any]`.
- Added `_axis_setter` and `_block_sizes_setter` custom setters so that
`axis` and `block_sizes` changes properly propagate to the calibrator
and maintain mutual exclusivity.
- `SequentialQuantizer.set_from_attribute_config()`: narrowed signature
to `list[QuantizerAttributeConfig] | list[dict[str, Any]]` (removed the
old union with single values).
- **`algorithms.py`**:
- Updated `_match_quantizer_cfg()` to iterate the list and return
`(matched_cfg, matched_enable)` tuple with last-match-wins.
- Updated `_cfg_to_dict()`, `estimate_quant_compression()`, and
`QuantRecipe` to work with the list-based format.
- Updated `get_auto_quantize_config()` to emit list-format `quant_cfg`.
- **`model_quant.py`**: `disable_quantizer()` / `enable_quantizer()` now
call `set_quantizer_attributes_partial()` directly instead of the
deprecated `set_quantizer_attribute()`. Updated docstrings and code
examples to show the list format.
- **`utils/core_utils.py`**: `disable_lora_quantizers_in_config()` and
`update_quant_cfg_with_kv_cache_quant()` updated to append
`QuantizerCfgEntry` dicts to the list.
- **Other**: minor updates to `backends/fp8_per_tensor_gemm.py`,
`backends/nvfp4_gemm.py`, `compress.py`, `model_calib.py`,
`export/unified_export_hf.py`, and
`sparsity/attention_sparsity/conversion.py` to use the list format.
- **`onnx/llm_export_utils/quantization_utils.py`**: Updated
quantization config construction to use list format.
**YAML recipes (`modelopt_recipes/`)**
- Converted all 5 general PTQ recipes to the new list format:
- `general/ptq/fp8_default-fp8_kv.yml`
- `general/ptq/nvfp4_default-fp8_kv.yml`
- `general/ptq/nvfp4_experts_only-fp8_kv.yml`
- `general/ptq/nvfp4_mlp_only-fp8_kv.yml`
- `general/ptq/nvfp4_omlp_only-fp8_kv.yml`
- Converted model-specific recipe:
`models/Step3.5-Flash/nvfp4-mlp-only.yaml`
**Documentation (`docs/`)**
- New guide: `docs/source/guides/_quant_cfg.rst` — comprehensive
reference covering entry format, ordering semantics, entry atomicity,
`enable` vs `cfg` independence, `parent_class` filtering, and common
patterns (deny-all-then-enable, customizing a built-in config, building
from scratch).
- Updated `_pytorch_quantization.rst` code examples to show the list
format with `copy.deepcopy` and `.append()`.
- Added `_quant_cfg.rst` to the quantization guide table of contents.
**Examples**
- Updated all quantization examples to use the list format:
`deepseek/ptq.py`, `diffusers/quantization/config.py`,
`llm_ptq/hf_ptq.py`, `llm_qat/main.py`, `vllm_serve/vllm_ptq_utils.py`,
`llm_autodeploy/run_auto_quantize.py`, `llm_eval/quantization_utils.py`,
`llm_ptq/example_utils.py`,
`windows/torch_onnx/diffusers/qad_example/sample_example_qad_diffusers.py`,
and 2 notebooks.
**Tests**
- New test file:
`tests/unit/torch/quantization/test_config_validation.py` — unit tests
for `need_calibration()`, `normalize_quant_cfg_list()` (new format,
legacy format conversions, error cases),
`find_quant_cfg_entry_by_path()`, `_match_quantizer_cfg()`, and
`QuantizeConfig` Pydantic validators.
- Extended `tests/unit/torch/quantization/test_quantize_cpu.py` with
tests for `set_quantizer_attributes_full()` (atomicity, parent_class
filtering, SequentialQuantizer creation), list ordering, enable-only
entry behavior, and end-to-end legacy dict format.
- Updated 20+ existing test files across `tests/unit/`, `tests/gpu/`,
`tests/gpu_megatron/`, and `tests/_test_utils/` to use the list format.
##### Backward compatibility
`normalize_quant_cfg_list()` is called automatically by the
`QuantizeConfig` Pydantic `mode="before"` validator, so existing code
passing the old dict-based format (flat dict like `{"*weight_quantizer":
{"num_bits": 8}}`, single-key dict lists, or `nn.*`-scoped dicts with
`parent_class` semantics) continues to work without modification. The
legacy `"default"` key is converted to `quantizer_name: "*"`.
`set_quantizer_attribute()` is preserved as a deprecated wrapper around
`set_quantizer_attributes_partial()`.
#### Test coverage
- **Unit tests**: new `test_config_validation.py` with tests for
normalization, validation, path lookup, and cfg matching. Extended
`test_quantize_cpu.py` with tests for full/partial attribute setting,
ordering, atomicity, and legacy backward compatibility.
- **System testing**:
```
python examples/llm_ptq/hf_ptq.py \
--model Qwen/Qwen3-8B \
--recipe general/ptq/fp8_default-fp8_kv \
--export_path=build/fp8_default-fp8_kv42 \
--calib_size=16 \
--batch_size=0 \
--trust_remote_code \
--export_fmt=hf
```
### Additional Information
<!-- E.g. related issue. -->
---------
Signed-off-by: Shengliang Xu <shengliangx@nvidia.com>
## What does this PR do?
**Type of change:** new tests, Bug fix <!-- Use one of the following:
Bug fix, new feature, new example, new tests, documentation. -->
**Overview:**
- **Fixed the INT8 config issue**
- **Add HF checkpoint export test coverage**
1. The `--hf-ckpt-dir` export path had zero test coverage. This MR adds
tests at two levels:
2. Unit tests (tests/unit/torch/export/test_export_diffusers.py):
- Extended test_export_diffusers_real_quantized to parametrize over
INT8, INT8 SmoothQuant, FP8, and FP4 configs
- (previously only FP8). This gives 3 models x 4 configs = 12 test
cases.
3. GPU integration tests
(tests/gpu/torch/export/test_export_diffusers_hf_ckpt.py)
- New file testing the full quantize.py --hf-ckpt-dir pipeline via
subprocess with 4 combos:
- SDXL INT8 smoothquant min-mean (the exact scenario that triggered the
bug)
- Flux INT8 smoothquant min-mean
- SDXL FP8
- Flux FP4
## Usage
<!-- You can potentially add a usage example below. -->
```python
# Add a code snippet demonstrating how to use this
```
## Testing
<!-- Mention how have you tested your change if applicable. -->
## Before your PR is "*Ready for review*"
<!-- If you haven't finished some of the above items you can still open
`Draft` PR. -->
- **Make sure you read and follow [Contributor
guidelines](https://github.com/NVIDIA/Model-Optimizer/blob/main/CONTRIBUTING.md)**
and your commits are signed.
- **Is this change backward compatible?**:No <!--- If No, explain why.
-->
- **Did you write any new necessary tests?**: Yes
- **Did you add or update any necessary documentation?**:No
- **Did you update
[Changelog](https://github.com/NVIDIA/Model-Optimizer/blob/main/CHANGELOG.rst)?**:No
<!--- Only for new features, API changes, critical bug fixes or bw
breaking changes. -->
## Additional Information
<!-- E.g. related issue. -->
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
## Release Notes
* **Tests**
* Added test coverage for exporting Diffusers models with Hugging Face
checkpoints across multiple quantization formats (INT8, FP8, FP4)
* Extended quantization export testing to validate multiple
configuration scenarios
* **Chores**
* Refined INT8 quantization configuration with improved calibrator
support for convolution layers
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Signed-off-by: Jingyu Xin <jingyux@nvidia.com>
## What does this PR do?
**Type of change:** documentation <!-- Use one of the following: Bug
fix, new feature, new example, new tests, documentation. -->
**Overview:**
1. Added multi‑backbone support for quantization: --backbone now accepts
space- or comma-separated lists and resolves to a list of backbone
modules.
2. Introduced PipelineManager.iter_backbones() to iterate named backbone
modules and updated get_backbone() to return a single module or a
ModuleList for multi‑backbone.
3. Updated ExportManager to save/restore per‑backbone checkpoints when a
directory is provided, with {backbone_name}.pt files, and to create
target directories when missing.
4. Simplified save_checkpoint() calls to rely on the registered
pipeline_manager by default.
**Usage: **
```bash
python quantize.py --model wan2.2-t2v-14b --format fp4 --batch-size 1 --calib-size 32 \
--n-steps 30 --backbone transformer transformer_2 --model-dtype BFloat16 \
--quantized-torch-ckpt-save-path ./wan22_mo_ckpts \
--hf-ckpt-dir ./wan2.2-t2v-14b
```
Plans
- [x] [1/4] Add the basic functionalities to support limited image
models with NVFP4 + FP8, with some refactoring on the previous LLM code
and the diffusers example. PIC: @jingyu-ml
- [x] [2/4] Add support to more video gen models. PIC: @jingyu-ml
- [x] [3/4] Add test cases, refactor on the doc, and all related README.
PIC: @jingyu-ml
- [ ] [4/4] Add the final support to ComfyUI. PIC @jingyu-ml
## Testing
<!-- Mention how have you tested your change if applicable. -->
## Before your PR is "*Ready for review*"
<!-- If you haven't finished some of the above items you can still open
`Draft` PR. -->
- **Make sure you read and follow [Contributor
guidelines](https://github.com/NVIDIA/Model-Optimizer/blob/main/CONTRIBUTING.md)**
and your commits are signed.
- **Is this change backward compatible?**: No <!--- If No, explain why.
-->
- **Did you write any new necessary tests?**:No
- **Did you add or update any necessary documentation?**: Yes
- **Did you update
[Changelog](https://github.com/NVIDIA/Model-Optimizer/blob/main/CHANGELOG.rst)?**:
Yes <!--- Only for new features, API changes, critical bug fixes or bw
breaking changes. -->
## Additional Information
<!-- E.g. related issue. -->
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
## Release Notes
* **New Features**
* Unified Hugging Face export support for diffusers pipelines and
components
* LTX-2 and Wan2.2 (T2V) support in diffusers quantization workflow
* Comprehensive ONNX export and TensorRT engine build documentation for
diffusion models
* **Documentation**
* Updated to clarify support for both transformers and diffusers models
in unified export API
* Expanded diffusers examples with LoRA fusion guidance and additional
model options (Flux, SD3, SDXL variants)
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Signed-off-by: Jingyu Xin <jingyux@nvidia.com>
Shengliang Xu