[Bugfix] Fix LoRA bug (#4032)

vllm/lora/layers.py

@@ -32,14 +32,17 @@ if TYPE_CHECKING:
 def _get_lora_device(base_layer: nn.Module) -> torch.device:
     # code borrowed from https://github.com/fmmoret/vllm/blob/fm-support-lora-on-quantized-models/vllm/lora/layers.py#L34
     """Returns the device for where to place the LoRA tensors."""
+    # unquantizedLinear
     if hasattr(base_layer, "weight"):
         return base_layer.weight.device
-    if hasattr(base_layer, "linear_weights") and isinstance(
-            base_layer.linear_weights, dict):
-        values = list(base_layer.linear_weights.values())
-        if len(values) and isinstance(values[0], torch.Tensor):
-            return values[0].device
-    raise ValueError(f"Unsupported base layer: {base_layer}")
+    # GPTQ/AWQ/SqueezeLLM
+    elif hasattr(base_layer, "qweight"):
+        return base_layer.qweight.device
+    # marlin
+    elif hasattr(base_layer, "B"):
+        return base_layer.B.device
+    else:
+        raise ValueError(f"Unsupported base layer: {base_layer}")
 
 
 def _apply_lora(