[Misc][LoRA] Add PEFTHelper for LoRA (#11003)

Signed-off-by: Jee Jee Li <pandaleefree@gmail.com>

tests/lora/test_lora_manager.py

@@ -1,3 +1,4 @@
+import json
 import os
 from typing import Dict, List
 
@@ -13,6 +14,7 @@ from vllm.lora.layers import (ColumnParallelLinearWithLoRA,
 from vllm.lora.lora import LoRALayerWeights, PackedLoRALayerWeights
 from vllm.lora.models import (LoRAMapping, LoRAModel, LoRAModelManager,
                               LRUCacheLoRAModelManager)
+from vllm.lora.peft_helper import PEFTHelper
 from vllm.lora.request import LoRARequest
 from vllm.lora.worker_manager import (LRUCacheWorkerLoRAManager,
                                       WorkerLoRAManager)
@@ -30,18 +32,68 @@ CUDA_DEVICES = [
 ]
 
 
+def test_peft_helper(sql_lora_files):
+    lora_config_path = os.path.join(sql_lora_files, "adapter_config.json")
+    with open(lora_config_path) as f:
+        config = json.load(f)
+    peft_helper = PEFTHelper.from_dict(config)
+    assert peft_helper.r == 8
+    assert peft_helper.lora_alpha == 16
+    assert peft_helper.target_modules == [
+        "q_proj",
+        "v_proj",
+        "k_proj",
+        "o_proj",
+        "gate_proj",
+        "up_proj",
+        "down_proj",
+        "embed_tokens",
+        "lm_head",
+    ]
+
+    expected_error = "vLLM only supports modules_to_save being None."
+    with pytest.raises(ValueError, match=expected_error):
+        config = dict(
+            r=8,
+            lora_alpha=16,
+            target_modules=["gate_proj"],
+            modules_to_save=["lm_head"],
+        )
+        PEFTHelper.from_dict(config)
+    expected_error = "vLLM does not yet support RSLoRA."
+    with pytest.raises(ValueError, match=expected_error):
+        config = dict(r=8,
+                      lora_alpha=16,
+                      target_modules=["gate_proj"],
+                      use_rslora=True)
+        PEFTHelper.from_dict(config)
+
+    expected_error = "vLLM does not yet support DoRA."
+    with pytest.raises(ValueError, match=expected_error):
+        config = dict(r=8,
+                      lora_alpha=16,
+                      target_modules=["gate_proj"],
+                      use_dora=True)
+        PEFTHelper.from_dict(config)
+
+
 @pytest.mark.parametrize("device", CUDA_DEVICES)
 def test_from_lora_tensors(sql_lora_files, device):
     tensors = load_file(
         os.path.join(sql_lora_files, "adapter_model.safetensors"))
     new_embeddings = load_file(
         os.path.join(sql_lora_files, "new_embeddings.safetensors"))
+
+    lora_config_path = os.path.join(sql_lora_files, "adapter_config.json")
+    with open(lora_config_path) as f:
+        config = json.load(f)
+
+    peft_helper = PEFTHelper.from_dict(config)
     lora_model = LoRAModel.from_lora_tensors(
         1,
-        8,
-        16,
         tensors,
-        device,
+        peft_helper=peft_helper,
+        device=device,
         embeddings=new_embeddings,
         embedding_modules=EMBEDDING_MODULES,
         embedding_padding_modules=EMBEDDING_PADDING_MODULES)