[1/N][refactor] torchair deepseek modeling refactor (#2384)

### What this PR does / why we need it?

Move torchair related model arch into torchair moduel to make the code
clear. Next step we'll remove all torchair related code outside of
torchair moduel.

### Does this PR introduce _any_ user-facing change?
No.

- vLLM version: v0.10.0
- vLLM main:
08d5f7113a

Signed-off-by: linfeng-yuan <1102311262@qq.com>

vllm_ascend/torchair/models/torchair_deepseek_mtp.py

@@ -0,0 +1,218 @@
+#
+# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
+# Adapted from vllm/model_executor/models/deepseek_mtp.py
+# Copyright 2023 The vLLM team.
+#
+# This file is a part of the vllm-ascend project.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import List, Optional
+
+import torch
+import torch.nn as nn
+from transformers import PretrainedConfig
+from vllm.attention.backends.abstract import AttentionMetadata
+from vllm.config import CacheConfig, ModelConfig, VllmConfig
+from vllm.model_executor.layers.layernorm import RMSNorm
+from vllm.model_executor.layers.logits_processor import LogitsProcessor
+from vllm.model_executor.layers.quantization import QuantizationConfig
+from vllm.model_executor.layers.sampler import get_sampler
+from vllm.model_executor.layers.vocab_parallel_embedding import (
+    ParallelLMHead, VocabParallelEmbedding)
+from vllm.model_executor.models.deepseek_mtp import (
+    DeepSeekMTP, DeepSeekMultiTokenPredictor, DeepSeekMultiTokenPredictorLayer,
+    SharedHead)
+from vllm.model_executor.models.utils import maybe_prefix
+from vllm.model_executor.sampling_metadata import SamplingMetadata
+from vllm.sequence import IntermediateTensors
+
+from vllm_ascend.torchair.models.torchair_deepseek_v2 import \
+    TorchairDeepseekV2DecoderLayer
+
+
+class TorchairDeepSeekShareHead(SharedHead):
+
+    def __init__(self,
+                 config: PretrainedConfig,
+                 quant_config: Optional[QuantizationConfig] = None,
+                 prefix: str = "") -> None:
+        nn.Module.__init__(self)
+        self.norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
+        self.head = ParallelLMHead(config.vocab_size,
+                                   config.hidden_size,
+                                   quant_config=quant_config,
+                                   prefix=maybe_prefix(prefix, "head"))
+
+
+class TorchairDeepSeekMultiTokenPredictorLayer(DeepSeekMultiTokenPredictorLayer
+                                               ):
+
+    def __init__(
+        self,
+        config: PretrainedConfig,
+        prefix: str,
+        model_config: ModelConfig,
+        cache_config: Optional[CacheConfig] = None,
+        quant_config: Optional[QuantizationConfig] = None,
+    ) -> None:
+        nn.Module.__init__(self)
+
+        self.enorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
+        self.hnorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
+        self.eh_proj = nn.Linear(config.hidden_size * 2,
+                                 config.hidden_size,
+                                 bias=False)
+        self.shared_head = TorchairDeepSeekShareHead(config=config,
+                                                     quant_config=quant_config,
+                                                     prefix=maybe_prefix(
+                                                         prefix,
+                                                         "shared_head"))
+        self.mtp_block = TorchairDeepseekV2DecoderLayer(
+            config, prefix, model_config, cache_config, quant_config)
+
+    def forward(
+        self,
+        input_ids: torch.Tensor,
+        positions: torch.Tensor,
+        kv_cache: torch.Tensor,
+        attn_metadata: AttentionMetadata,
+        previous_hidden_states: torch.Tensor,
+        inputs_embeds: Optional[torch.Tensor] = None,
+        spec_step_index: int = 0,
+    ) -> torch.Tensor:
+        assert inputs_embeds is not None
+        # masking inputs at position 0, as not needed by MTP
+        inputs_embeds = torch.where((positions == 0).unsqueeze(-1),
+                                    torch.zeros_like(inputs_embeds),
+                                    inputs_embeds)
+        inputs_embeds = self.enorm(inputs_embeds)
+        previous_hidden_states = self.hnorm(previous_hidden_states)
+
+        hidden_states = self.eh_proj(
+            torch.cat([inputs_embeds, previous_hidden_states], dim=-1))
+
+        hidden_states, residual = self.mtp_block(positions=positions,
+                                                 hidden_states=hidden_states,
+                                                 kv_cache=kv_cache,
+                                                 attn_metadata=attn_metadata,
+                                                 residual=None)
+        hidden_states = residual + hidden_states
+        return hidden_states
+
+
+class TorchairDeepSeekMultiTokenPredictor(DeepSeekMultiTokenPredictor):
+
+    def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
+        nn.Module.__init__(self)
+        config = vllm_config.model_config.hf_config
+        self.mtp_start_layer_idx = config.num_hidden_layers
+        self.num_mtp_layers = config.num_nextn_predict_layers
+        # to map the exact layer index from weights
+        self.layers = torch.nn.ModuleDict({
+            str(idx):
+            TorchairDeepSeekMultiTokenPredictorLayer(
+                config,
+                f"{prefix}.layers.{idx}",
+                model_config=vllm_config.model_config,
+                cache_config=vllm_config.cache_config,
+                quant_config=vllm_config.quant_config,
+            )
+            for idx in range(self.mtp_start_layer_idx,
+                             self.mtp_start_layer_idx + self.num_mtp_layers)
+        })
+        self.embed_tokens = VocabParallelEmbedding(
+            config.vocab_size,
+            config.hidden_size,
+        )
+
+        # Note: torch._dynamo.exc.Unsupported: builtin: str
+        self.layers_list = [
+            self.layers[str(idx)]
+            for idx in range(self.mtp_start_layer_idx,
+                             self.mtp_start_layer_idx + self.num_mtp_layers)
+        ]
+        self.logits_processor = LogitsProcessor(config.vocab_size)
+
+    def forward(
+        self,
+        input_ids: torch.Tensor,
+        positions: torch.Tensor,
+        kv_caches: torch.Tensor,
+        attn_metadata: AttentionMetadata,
+        previous_hidden_states: torch.Tensor,
+        inputs_embeds: Optional[torch.Tensor] = None,
+        spec_step_idx: int = 0,
+    ) -> torch.Tensor:
+        if inputs_embeds is None:
+            inputs_embeds = self.embed_tokens(input_ids)
+        current_step_idx = (spec_step_idx % self.num_mtp_layers)
+        step_kv_cache = kv_caches[
+            current_step_idx] if kv_caches is not None else None
+        return self.layers_list[current_step_idx](
+            input_ids,
+            positions,
+            step_kv_cache,
+            attn_metadata,
+            previous_hidden_states,
+            inputs_embeds,
+            current_step_idx,
+        )
+
+    def compute_logits(
+        self,
+        hidden_states: torch.Tensor,
+        sampling_metadata: SamplingMetadata,
+        spec_step_idx: int = 0,
+    ) -> torch.Tensor:
+        current_step_idx = (spec_step_idx % self.num_mtp_layers)
+        mtp_layer = self.layers_list[current_step_idx]
+        logits = self.logits_processor(mtp_layer.shared_head.head,
+                                       mtp_layer.shared_head(hidden_states),
+                                       sampling_metadata)
+        return logits
+
+
+class TorchairDeepSeekMTP(DeepSeekMTP):
+    # NOTE 1.The quantized MTP layer of deepseek on the NPU is not quantized;
+    # NOTE 2.The description file generated by the current msmodelslim tool does not have
+    # MTP layer info. Please manually add it and set the value to FLOAT.
+    packed_modules_mapping = {
+        "gate_up_proj": ["gate_proj", "up_proj"],
+        "experts":
+        ["experts.0.gate_proj", "experts.0.up_proj", "experts.0.down_proj"]
+    }
+
+    def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
+        nn.Module.__init__(self)
+        self.config = vllm_config.model_config.hf_config
+        self.model = TorchairDeepSeekMultiTokenPredictor(
+            vllm_config=vllm_config, prefix=maybe_prefix(prefix, "model"))
+
+        self.sampler = get_sampler()
+
+    def forward(
+        self,
+        input_ids: torch.Tensor,
+        positions: torch.Tensor,
+        kv_caches: Optional[List[torch.Tensor]] = None,
+        attn_metadata: Optional[AttentionMetadata] = None,
+        previous_hidden_states: Optional[torch.Tensor] = None,
+        intermediate_tensors: Optional[IntermediateTensors] = None,
+        inputs_embeds: Optional[torch.Tensor] = None,
+        spec_step_idx: int = 0,
+    ) -> torch.Tensor:
+        hidden_states = self.model(input_ids, positions, kv_caches,
+                                   attn_metadata, previous_hidden_states,
+                                   inputs_embeds, spec_step_idx)
+        return hidden_states

vllm_ascend/torchair/models/torchair_deepseek_v3.py

@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
+# Copyright 2023 The vLLM team.
+# Copyright 2023 DeepSeek-AI and the HuggingFace Inc. team. All rights reserved.
+#
+# This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
+# and OPT implementations in this library. It has been modified from its
+# original forms to accommodate minor architectural differences compared
+# to GPT-NeoX and OPT used by the Meta AI team that trained the model.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from vllm_ascend.torchair.models.torchair_deepseek_v2 import \
+    TorchairDeepseekV2ForCausalLM
+
+
+class TorchairDeepseekV3ForCausalLM(TorchairDeepseekV2ForCausalLM):
+    pass

vllm_ascend/torchair/torchair_model_runner.py

@@ -27,6 +27,7 @@ from vllm.logger import logger
 
 from vllm_ascend.platform import NPUPlatform
 from vllm_ascend.torchair.utils import (check_torchair_cache_exist,
+                                        register_torchair_model,
                                         write_kv_cache_bytes_to_file)
 from vllm_ascend.utils import (ACL_FORMAT_FRACTAL_ND, ACL_FORMAT_FRACTAL_NZ,
                                maybe_converting_weight_acl_format)
@@ -37,6 +38,7 @@ class NPUTorchairModelRunner(NPUModelRunner):
 
     def __init__(self, vllm_config: VllmConfig, device: torch.device):
         super().__init__(vllm_config, device)
+        register_torchair_model()
 
     def _get_forward_metadata_across_dp_and_pad(
             self, num_tokens: int, with_prefill: bool, enable_dbo: bool

vllm_ascend/torchair/utils.py

@@ -96,3 +96,22 @@ def npu_wait_tensor(self: torch.Tensor,
                     *,
                     enabled: bool = True):
     return _npu_wait_tensor(self, dependency) if enabled else self
+
+
+def register_torchair_model():
+    from vllm import ModelRegistry
+
+    ModelRegistry.register_model(
+        "DeepSeekMTPModel",
+        "vllm_ascend.torchair.models.torchair_deepseek_mtp:TorchairDeepSeekMTP"
+    )
+
+    ModelRegistry.register_model(
+        "DeepseekV2ForCausalLM",
+        "vllm_ascend.torchair.models.torchair_deepseek_v2:TorchairDeepseekV2ForCausalLM"
+    )
+
+    ModelRegistry.register_model(
+        "DeepseekV3ForCausalLM",
+        "vllm_ascend.torchair.models.torchair_deepseek_v3:TorchairDeepseekV3ForCausalLM"
+    )