[https://nvbugs/5569713][fix] Disable fp8 deep gemm for EXAONE-4.0-32B-FP8 (NVIDIA#8429)

Signed-off-by: Junyi Xu <219237550+JunyiXu-nv@users.noreply.github.com>
Signed-off-by: Mike Iovine <6158008+mikeiovine@users.noreply.github.com>

Author: JunyiXu-nv

tensorrt_llm/_torch/models/modeling_exaone4.py

@@ -5,6 +5,7 @@
 
 from tensorrt_llm._torch.modules.qk_norm_attention import QKNormRoPEAttention
 from tensorrt_llm.functional import PositionEmbeddingType
+from tensorrt_llm.quantization import QuantAlgo
 
 from ..attention_backend import AttentionMetadata
 from ..attention_backend.interface import (PositionalEmbeddingParams,
@@ -54,7 +55,8 @@ class Exaone4Attention(QKNormRoPEAttention):
     def __init__(self,
                  model_config: ModelConfig[Exaone4Config],
                  layer_idx: Optional[int] = None,
-                 fuse_qk_norm_rope: bool = False):
+                 fuse_qk_norm_rope: bool = False,
+                 disable_deep_gemm: bool = False):
         config = model_config.pretrained_config
 
         self.attention_window_size = None
@@ -88,6 +90,7 @@ def __init__(self,
             layer_idx=layer_idx,
             dtype=config.torch_dtype,
             config=model_config,
+            disable_deep_gemm=disable_deep_gemm,
         )
 
     def forward(
@@ -128,9 +131,17 @@ def __init__(
         self.is_quanted = model_config.quant_config and model_config.quant_config.quant_mode.has_any_quant(
         )
 
+        disable_deep_gemm = False
+        quant_config = getattr(model_config, "quant_config", None)
+        if quant_config is not None:
+            # EXAONE4 fp8 has an illegal memory access issue with deep_gemm.
+            disable_deep_gemm = getattr(quant_config, "quant_algo",
+                                        None) == QuantAlgo.FP8_BLOCK_SCALES
+
         self.self_attn = Exaone4Attention(
             model_config,
             layer_idx=layer_idx,
+            disable_deep_gemm=disable_deep_gemm,
         )
 
         self.mlp = GatedMLP(
@@ -140,6 +151,7 @@ def __init__(
             dtype=config.torch_dtype,
             config=model_config,
             layer_idx=layer_idx,
+            disable_deep_gemm=disable_deep_gemm,
         )
 
         self.post_attention_layernorm = RMSNorm(hidden_size=config.hidden_size,

tests/integration/test_lists/test-db/l0_b200.yml

@@ -78,6 +78,7 @@ l0_b200:
   - unittest/_torch/modeling -k "modeling_gpt_oss"
   - unittest/tools/test_layer_wise_benchmarks.py::test_deepseek_r1_ctx_dep[1]
   - unittest/tools/test_layer_wise_benchmarks.py::test_qwen3_next_gen_tep[1]
+  - unittest/_torch/modeling/test_modeling_exaone4.py::TestEXAONE4::test_llm_load_1_FP8
     # ------------- AutoDeploy tests ---------------
   - accuracy/test_llm_api_autodeploy.py::TestLlama3_1_8B::test_auto_dtype[False-1]
   - unittest/_torch/auto_deploy/unit/singlegpu

tests/unittest/_torch/modeling/test_modeling_exaone4.py

@@ -1,3 +1,6 @@
+import json
+import os
+import shutil
 import unittest
 from copy import deepcopy
 from dataclasses import dataclass
@@ -50,8 +53,9 @@ class Exaone4Config(PretrainedConfig):
     "max_position_embeddings": 131072,
     "model_type": "exaone4",
     "num_attention_heads": 40,
-    "num_hidden_layers":
-    4,  #NOTE: For testing, we use 4 instead of 64(all layers)
+    # NOTE: For testing, we use 32 instead of 64(all layers)
+    # Increase from 4 to 32 to trigger the deep_gemm kernel issue
+    "num_hidden_layers": 32,
     "num_key_value_heads": 8,
     "pad_token_id": 0,
     "rms_norm_eps": 1e-05,
@@ -73,6 +77,15 @@ class Exaone4Config(PretrainedConfig):
     "attn_implementation": "flash_attention_2"
 }
 
+EXAONE4_FP8_QUANT_CONFIG = {
+    "quantization_config": {
+        "activation_scheme": "dynamic",
+        "modules_to_not_convert": None,
+        "quant_method": "fp8",
+        "weight_block_size": [128, 128]
+    },
+}
+
 
 @dataclass(repr=False)
 class Scenario:
@@ -387,3 +400,30 @@ def run_forward(input_ids, position_ids, attn_metadata):
         if graph_runner is not None:
             graph_runner.clear()
         kv_cache_manager.shutdown()
+
+    @parameterized.expand([None, "FP8"])
+    def test_llm_load(self, quant_algo):
+
+        def dump_config_json(dst_dir, config):
+            if os.path.exists(dst_dir):
+                shutil.rmtree(dst_dir)
+            os.makedirs(dst_dir)
+
+            dst_path = os.path.join(dst_dir, 'config.json')
+            with open(dst_path, 'w', encoding='utf-8') as f:
+                json.dump(config, f, indent=2, ensure_ascii=False)
+
+        config_dict = deepcopy(EXAONE4_SINGLE_LAYER_CONFIG)
+        if quant_algo == "FP8":
+            if getSMVersion() < 89:
+                self.skipTest(
+                    "This test is not supported in pre-Ada architecture")
+
+            config_dict.update(EXAONE4_FP8_QUANT_CONFIG)
+
+        tmp_model_dir = f"/tmp/exaone4_llm_load_test_model"
+        dump_config_json(tmp_model_dir, config_dict)
+        try:
+            tensorrt_llm.LLM(model=tmp_model_dir, load_format="dummy")
+        except Exception:
+            raise RuntimeError("Failed to load model.")