Add update expected / unexpected keys api to DiffusersQuantizer

src/diffusers/models/model_loading_utils.py

@@ -233,7 +233,7 @@ def load_model_dict_into_meta(
     empty_state_dict = model.state_dict()
 
     for param_name, param in state_dict.items():
-        if param_name not in empty_state_dict:
+        if unexpected_keys is not None and param_name in unexpected_keys:
             continue
 
         set_module_kwargs = {}
@@ -260,10 +260,16 @@ def load_model_dict_into_meta(
         # For compatibility with PyTorch load_state_dict which converts state dict dtype to existing dtype in model, and which
         # uses `param.copy_(input_param)` that preserves the contiguity of the parameter in the model.
         # Reference: https://github.com/pytorch/pytorch/blob/db79ceb110f6646523019a59bbd7b838f43d4a86/torch/nn/modules/module.py#L2040C29-L2040C29
-        old_param = model
-        splits = param_name.split(".")
-        for split in splits:
-            old_param = getattr(old_param, split)
+        if param_name in empty_state_dict:
+            old_param = model
+            splits = param_name.split(".")
+            for split in splits:
+                old_param = getattr(old_param, split)
+        else:
+            # hf_quantizer can add parameters that doesn't exist yet in the model and the empty_state_dict
+            # they will be created in create_quantized_param and hf_quantizer should handle the loading of these parameters
+            # these parameters will be in the loaded_state_dict from the model file instead when loading a pre_quantized model
+            old_param = None
 
         if not isinstance(old_param, (torch.nn.Parameter, torch.Tensor)):
             old_param = None
@@ -279,7 +285,9 @@ def load_model_dict_into_meta(
 
         # bnb params are flattened.
         # gguf quants have a different shape based on the type of quantization applied
-        if empty_state_dict[param_name].shape != param.shape:
+        # current parameter might not be in the empty_state_dict if the hf_quantizer needs to create it in create_quantized_param
+        # pass the to be created parameters to create_quantized_param instead
+        if param_name in empty_state_dict and empty_state_dict[param_name].shape != param.shape:
             if (
                 is_quantized
                 and hf_quantizer.pre_quantized

src/diffusers/models/modeling_utils.py

@@ -1564,12 +1564,17 @@ def _load_pretrained_model(
         dduf_entries: Optional[Dict[str, DDUFEntry]] = None,
         is_parallel_loading_enabled: Optional[bool] = False,
     ):
+        is_quantized = hf_quantizer is not None
         model_state_dict = model.state_dict()
         expected_keys = list(model_state_dict.keys())
+        if is_quantized:
+            expected_keys = hf_quantizer.update_expected_keys(model, expected_keys, loaded_keys)
         missing_keys = list(set(expected_keys) - set(loaded_keys))
-        if hf_quantizer is not None:
+        if is_quantized:
             missing_keys = hf_quantizer.update_missing_keys(model, missing_keys, prefix="")
         unexpected_keys = list(set(loaded_keys) - set(expected_keys))
+        if is_quantized:
+            unexpected_keys = hf_quantizer.update_unexpected_keys(model, unexpected_keys)
         # Some models may have keys that are not in the state by design, removing them before needlessly warning
         # the user.
         if cls._keys_to_ignore_on_load_unexpected is not None:

src/diffusers/quantizers/base.py

@@ -110,6 +110,28 @@ def update_missing_keys(self, model, missing_keys: List[str], prefix: str) -> Li
         """
         return missing_keys
 
+    def update_expected_keys(self, model, expected_keys: list[str], loaded_keys: list[str]) -> list[str]:
+        """
+        Override this method if you want to adjust the `update_expected_keys`.
+
+        Args:
+            expected_keys (`list[str]`, *optional*):
+                The list of the expected keys in the initialized model.
+            loaded_keys (`list[str]`, *optional*):
+                The list of the loaded keys in the checkpoint.
+        """
+        return expected_keys
+
+    def update_unexpected_keys(self, model, unexpected_keys: list[str]) -> list[str]:
+        """
+        Override this method if you want to adjust the `update_expected_keys`.
+
+        Args:
+            unexpected_keys (`list[str]`, *optional*):
+                The list of the unexpected keys in the checkpoint compared to the state dict of the model
+        """
+        return unexpected_keys
+
     def get_special_dtypes_update(self, model, torch_dtype: "torch.dtype") -> Dict[str, "torch.dtype"]:
         """
         returns dtypes for modules that are not quantized - used for the computation of the device_map in case one