feat: support LoRA for DeepSeek-OCR(Language Model part) (#31569)

Signed-off-by: zhima771 <15836938703@163.com>
Co-authored-by: Cyrus Leung <tlleungac@connect.ust.hk>
Co-authored-by: Jee Jee Li <pandaleefree@gmail.com>

docs/models/supported_models.md

@@ -677,7 +677,7 @@ These models primarily accept the [`LLM.generate`](./generative_models.md#llmgen
 | `ChameleonForConditionalGeneration` | Chameleon | T + I | `facebook/chameleon-7b`, etc. | | ✅︎ |
 | `Cohere2VisionForConditionalGeneration` | Command A Vision | T + I<sup>+</sup> | `CohereLabs/command-a-vision-07-2025`, etc. | | ✅︎ |
 | `DeepseekVLV2ForCausalLM`<sup>^</sup> | DeepSeek-VL2 | T + I<sup>+</sup> | `deepseek-ai/deepseek-vl2-tiny`, `deepseek-ai/deepseek-vl2-small`, `deepseek-ai/deepseek-vl2`, etc. | | ✅︎ |
-| `DeepseekOCRForCausalLM` | DeepSeek-OCR | T + I<sup>+</sup> | `deepseek-ai/DeepSeek-OCR`, etc. | | ✅︎ |
+| `DeepseekOCRForCausalLM` | DeepSeek-OCR | T + I<sup>+</sup> | `deepseek-ai/DeepSeek-OCR`, etc. | ✅︎ | ✅︎ |
 | `Ernie4_5_VLMoeForConditionalGeneration` | Ernie4.5-VL | T + I<sup>+</sup>/ V<sup>+</sup> | `baidu/ERNIE-4.5-VL-28B-A3B-PT`, `baidu/ERNIE-4.5-VL-424B-A47B-PT` | | ✅︎ |
 | `FuyuForCausalLM` | Fuyu | T + I | `adept/fuyu-8b`, etc. | | ✅︎ |
 | `Gemma3ForConditionalGeneration` | Gemma 3 | T + I<sup>E+</sup> | `google/gemma-3-4b-it`, `google/gemma-3-27b-it`, etc. | ✅︎ | ✅︎ |

vllm/model_executor/models/deepseek_ocr.py

@@ -14,9 +14,11 @@ from vllm.config import VllmConfig
 from vllm.config.multimodal import BaseDummyOptions
 from vllm.model_executor.models.interfaces import (
     MultiModalEmbeddings,
+    SupportsLoRA,
     SupportsMultiModal,
     SupportsPP,
 )
+from vllm.model_executor.models.module_mapping import MultiModelKeys
 from vllm.model_executor.models.utils import (
     AutoWeightsLoader,
     WeightsMapper,
@@ -343,7 +345,7 @@ class DeepseekOCRMultiModalProcessor(
     info=DeepseekOCRProcessingInfo,
     dummy_inputs=DeepseekOCRDummyInputsBuilder,
 )
-class DeepseekOCRForCausalLM(nn.Module, SupportsMultiModal, SupportsPP):
+class DeepseekOCRForCausalLM(nn.Module, SupportsMultiModal, SupportsPP, SupportsLoRA):
     hf_to_vllm_mapper = WeightsMapper(
         orig_to_new_prefix={
             # map prefix for language backbone
@@ -589,3 +591,13 @@ class DeepseekOCRForCausalLM(nn.Module, SupportsMultiModal, SupportsPP):
         loader = AutoWeightsLoader(self)
         autoloaded_weights = loader.load_weights(weights, mapper=self.hf_to_vllm_mapper)
         return autoloaded_weights
+
+    def get_mm_mapping(self) -> MultiModelKeys:
+        """
+        Get the module prefix in multimodal models
+        """
+        return MultiModelKeys.from_string_field(
+            language_model="language_model",
+            connector="projector",
+            tower_model=["sam_model", "vision_model"],
+        )