| 1 | # SPDX-License-Identifier: Apache-2.0 |
| 2 | # SPDX-FileCopyrightText: Copyright contributors to the vLLM project |
| 3 | """MTP draft model for DeepSeek V4 (internal codename: DeepseekV4). |
| 4 | |
| 5 | Split from ``deepseek_mtp.py`` because the V4 architecture introduces several |
| 6 | pieces that have no analogue in V3/V32: |
| 7 | * separate ``e_proj`` / ``h_proj`` with fp8 linear quantization (instead of |
| 8 | the fused ``eh_proj``); |
| 9 | * ``hc_head`` hypercompressed vocab projection applied in ``compute_logits``; |
| 10 | * ``DeepseekV4DecoderLayer`` with its own aux-stream management; |
| 11 | * V4-specific checkpoint weight-name remapping in ``load_weights``. |
| 12 | """ |
| 13 | |
| 14 | import typing |
| 15 | from collections.abc import Callable, Iterable |
| 16 | |
| 17 | import regex as re |
| 18 | import torch |
| 19 | import torch.nn as nn |
| 20 | |
| 21 | import vllm.envs as envs |
| 22 | from vllm.config import VllmConfig |
| 23 | from vllm.config.kernel import MEGA_MOE_BACKENDS |
| 24 | from vllm.distributed import ( |
| 25 | get_tensor_model_parallel_rank, |
| 26 | get_tensor_model_parallel_world_size, |
| 27 | ) |
| 28 | from vllm.forward_context import get_forward_context, is_forward_context_available |
| 29 | from vllm.logger import init_logger |
| 30 | from vllm.model_executor.kernels.mhc.tilelang import ( |
| 31 | hc_head_fused_kernel_tilelang, |
| 32 | mhc_post_tilelang, |
| 33 | ) |
| 34 | from vllm.model_executor.layers.fused_moe import ( |
| 35 | fused_moe_make_expert_params_mapping, |
| 36 | ) |
| 37 | from vllm.model_executor.layers.layernorm import RMSNorm |
| 38 | from vllm.model_executor.layers.linear import ReplicatedLinear |
| 39 | from vllm.model_executor.layers.logits_processor import LogitsProcessor |
| 40 | from vllm.model_executor.layers.vocab_parallel_embedding import ( |
| 41 | VocabParallelEmbedding, |
| 42 | ) |
| 43 | from vllm.model_executor.model_loader.mtp_validation import ( |
| 44 | is_mtp_completeness_check_enabled, |
| 45 | ) |
| 46 | from vllm.model_executor.model_loader.weight_utils import default_weight_loader |
| 47 | from vllm.model_executor.models.deepseek_mtp import SharedHead |
| 48 | from vllm.model_executor.models.deepseek_v2 import get_spec_layer_idx_from_weight_name |
| 49 | from vllm.model_executor.models.utils import maybe_prefix |
| 50 | from vllm.models.common.ops.sequence_parallel import ( |
| 51 | sp_all_gather, |
| 52 | sp_padding_mask, |
| 53 | sp_shard, |
| 54 | ) |
| 55 | from vllm.models.deepseek_v4.common.mm_preprocess import IMAGE_SENTINEL_BASE_ID |
| 56 | from vllm.models.deepseek_v4.common.ops.fused_mtp_input_rmsnorm import ( |
| 57 | _FUSED_MTP_INPUT_RMSNORM_KERNEL, |
| 58 | _MTP_SHARED_HEAD_RMSNORM_KERNEL, |
| 59 | ) |
| 60 | from vllm.sequence import IntermediateTensors |
| 61 | |
| 62 | from .model import ( |
| 63 | DeepseekV4DecoderLayer, |
| 64 | DeepseekV4Model, |
| 65 | _use_sequence_parallel, |
| 66 | make_deepseek_v4_expert_params_mapping, |
| 67 | prepare_mega_gate_routing_metadata, |
| 68 | ) |
| 69 | |
| 70 | logger = init_logger(__name__) |
| 71 | |
| 72 | # MoE expert scales are fused into per-layer w13/w2 tensors. The exact |
| 73 | # parameter suffix depends on which FusedMoEFactory method handles the experts: |
| 74 | # - fp4 experts (Mxfp4MoEMethod) register ``w{1,2,3}_weight_scale``; |
| 75 | # - fp8 experts (Fp8MoEMethod with block_quant=True) register |
| 76 | # ``w{1,2,3}_weight_scale_inv``. |
| 77 | # Other FP8 linear scales (including shared experts) always use |
| 78 | # ``.weight_scale_inv``. Mirrors the per-instance mapper built by |
| 79 | # ``_make_deepseek_v4_weights_mapper`` in deepseek_v4.py. |
| 80 | _EXPERT_SCALE_RE = re.compile(r"\.experts\.\d+\.w[123]\.scale$") |
| 81 | |
| 82 | |
| 83 | class DeepSeekV4MultiTokenPredictorLayer(nn.Module): |
| 84 | def __init__( |
| 85 | self, |
| 86 | vllm_config: VllmConfig, |
| 87 | topk_indices_buffer: torch.Tensor, |
| 88 | prefix: str, |
| 89 | aux_stream_list: list[torch.cuda.Stream] | None = None, |
| 90 | ) -> None: |
| 91 | super().__init__() |
| 92 | |
| 93 | assert vllm_config.speculative_config is not None |
| 94 | config = vllm_config.speculative_config.draft_model_config.hf_config |
| 95 | self.config = config |
| 96 | quant_config = vllm_config.quant_config |
| 97 | self.rms_norm_eps = config.rms_norm_eps |
| 98 | self.use_mega_moe = vllm_config.kernel_config.moe_backend in MEGA_MOE_BACKENDS |
| 99 | |
| 100 | self.enorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps) |
| 101 | self.hnorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps) |
| 102 | |
| 103 | # V4 keeps e_ and h_ proj separate (with fp8 linear quant) rather than |
| 104 | # fusing them the way V3 does with eh_proj. |
| 105 | self.e_proj = ReplicatedLinear( |
| 106 | config.hidden_size, |
| 107 | config.hidden_size, |
| 108 | bias=False, |
| 109 | return_bias=False, |
| 110 | quant_config=quant_config, |
| 111 | prefix=f"{prefix}.e_proj", |
| 112 | ) |
| 113 | self.h_proj = ReplicatedLinear( |
| 114 | config.hidden_size, |
| 115 | config.hidden_size, |
| 116 | bias=False, |
| 117 | return_bias=False, |
| 118 | quant_config=quant_config, |
| 119 | prefix=f"{prefix}.h_proj", |
| 120 | ) |
| 121 | |
| 122 | self.hc_eps = config.hc_eps |
| 123 | self.hc_mult = config.hc_mult |
| 124 | self.hc_dim = self.hc_mult * config.hidden_size |
| 125 | self.hc_head_fn = nn.Parameter( |
| 126 | torch.empty(self.hc_mult, self.hc_dim, dtype=torch.float32), |
| 127 | requires_grad=False, |
| 128 | ) |
| 129 | self.hc_head_base = nn.Parameter( |
| 130 | torch.empty(self.hc_mult, dtype=torch.float32), |
| 131 | requires_grad=False, |
| 132 | ) |
| 133 | self.hc_head_scale = nn.Parameter( |
| 134 | torch.empty(1, dtype=torch.float32), |
| 135 | requires_grad=False, |
| 136 | ) |
| 137 | |
| 138 | self.shared_head = SharedHead( |
| 139 | config=config, prefix=prefix, quant_config=quant_config |
| 140 | ) |
| 141 | self.mtp_block = DeepseekV4DecoderLayer( |
| 142 | vllm_config, |
| 143 | prefix, |
| 144 | topk_indices_buffer=topk_indices_buffer, |
| 145 | aux_stream_list=aux_stream_list, |
| 146 | ) |
| 147 | |
| 148 | if vllm_config.kernel_config.enable_jit_warmup: |
| 149 | _FUSED_MTP_INPUT_RMSNORM_KERNEL.register_warmup() |
| 150 | _MTP_SHARED_HEAD_RMSNORM_KERNEL.register_warmup() |
| 151 | |
| 152 | def forward( |
| 153 | self, |
| 154 | input_ids: torch.Tensor, |
| 155 | positions: torch.Tensor, |
| 156 | previous_hidden_states: torch.Tensor, |
| 157 | inputs_embeds: torch.Tensor | None = None, |
| 158 | spec_step_index: int = 0, |
| 159 | ) -> torch.Tensor: |
| 160 | assert inputs_embeds is not None |
| 161 | # Target stashes pre-hc_head residual as flat (T, hc_mult * D); |
| 162 | # reshape to (T, hc_mult, D) — the training-time layout — before |
| 163 | # the fused norm pass so both inputs are 3D-friendly. |
| 164 | previous_hidden_states = previous_hidden_states.view( |
| 165 | -1, self.hc_mult, self.config.hidden_size |
| 166 | ) |
| 167 | # Fused: mask inputs at position 0 (not needed by MTP), enorm, hnorm. |
| 168 | inputs_embeds, previous_hidden_states = _FUSED_MTP_INPUT_RMSNORM_KERNEL( |
| 169 | inputs_embeds, |
| 170 | positions, |
| 171 | previous_hidden_states, |
| 172 | self.enorm.weight.data, |
| 173 | self.hnorm.weight.data, |
| 174 | self.enorm.variance_epsilon, |
| 175 | self.hc_mult, |
| 176 | ) |
| 177 | if self.mtp_block.use_sequence_parallel: |
| 178 | if envs.VLLM_MOE_SKIP_PADDING and is_forward_context_available(): |
| 179 | forward_context = get_forward_context() |
| 180 | forward_context.is_padding = sp_padding_mask( |
| 181 | forward_context.is_padding, inputs_embeds |
| 182 | ) |
| 183 | inputs_embeds = sp_shard(inputs_embeds) |
| 184 | previous_hidden_states = sp_shard(previous_hidden_states) |
| 185 | hidden_states = self.h_proj(previous_hidden_states) + self.e_proj( |
| 186 | inputs_embeds |
| 187 | ).unsqueeze(-2) |
| 188 | mega_gate_metadata = None |
| 189 | if self.use_mega_moe: |
| 190 | routing_input_ids = input_ids |
| 191 | if self.mtp_block.use_sequence_parallel: |
| 192 | routing_input_ids = sp_shard(routing_input_ids) |
| 193 | mega_gate_metadata = prepare_mega_gate_routing_metadata( |
| 194 | routing_input_ids, |
| 195 | has_hash_routing=False, |
| 196 | image_sentinel_base_id=IMAGE_SENTINEL_BASE_ID |
| 197 | if getattr(self.config, "vision_n_layers", 0) > 0 |
| 198 | else None, |
| 199 | ) |
| 200 | hidden_states, residual, post_mix, res_mix = self.mtp_block( |
| 201 | positions=positions, |
| 202 | x=hidden_states, |
| 203 | input_ids=input_ids, |
| 204 | mega_gate_metadata=mega_gate_metadata, |
| 205 | ) |
| 206 | hidden_states = mhc_post_tilelang(hidden_states, residual, post_mix, res_mix) |
| 207 | if self.mtp_block.use_sequence_parallel: |
| 208 | hidden_states = sp_all_gather(hidden_states)[: positions.shape[0]] |
| 209 | # Return the flat pre-hc_head residual so it can be re-fed as the |
| 210 | # next spec step's `previous_hidden_states` when |
| 211 | # num_speculative_tokens > 1. hc_head is deferred to compute_logits. |
| 212 | return hidden_states.flatten(1) |
| 213 | |
| 214 | |
| 215 | class DeepSeekV4MultiTokenPredictor(nn.Module): |
| 216 | def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""): |
| 217 | super().__init__() |
| 218 | config = vllm_config.model_config.hf_config |
| 219 | self.mtp_start_layer_idx = config.num_hidden_layers |
| 220 | self.num_mtp_layers = config.num_nextn_predict_layers |
| 221 | |
| 222 | topk_tokens = config.index_topk |
| 223 | self.topk_indices_buffer = torch.empty( |
| 224 | vllm_config.scheduler_config.max_num_batched_tokens, |
| 225 | topk_tokens, |
| 226 | dtype=torch.int32, |
| 227 | ) |
| 228 | |
| 229 | # Three aux streams shared across all MTP layers, mirroring DeepseekV4Model. |
| 230 | aux_stream_list = [torch.cuda.Stream() for _ in range(3)] |
| 231 | |
| 232 | # to map the exact layer index from weights |
| 233 | self.layers = torch.nn.ModuleDict( |
| 234 | { |
| 235 | str(idx): DeepSeekV4MultiTokenPredictorLayer( |
| 236 | vllm_config, |
| 237 | self.topk_indices_buffer, |
| 238 | f"{prefix}.layers.{idx}", |
| 239 | aux_stream_list=aux_stream_list, |
| 240 | ) |
| 241 | for idx in range( |
| 242 | self.mtp_start_layer_idx, |
| 243 | self.mtp_start_layer_idx + self.num_mtp_layers, |
| 244 | ) |
| 245 | } |
| 246 | ) |
| 247 | self.embed_tokens = VocabParallelEmbedding( |
| 248 | config.vocab_size, |
| 249 | config.hidden_size, |
| 250 | prefix=maybe_prefix(prefix, "embed_tokens"), |
| 251 | ) |
| 252 | self.logits_processor = LogitsProcessor(config.vocab_size) |
| 253 | |
| 254 | def embed_input_ids(self, input_ids: torch.Tensor) -> torch.Tensor: |
| 255 | return self.embed_tokens(input_ids) |
| 256 | |
| 257 | def forward( |
| 258 | self, |
| 259 | input_ids: torch.Tensor, |
| 260 | positions: torch.Tensor, |
| 261 | previous_hidden_states: torch.Tensor, |
| 262 | inputs_embeds: torch.Tensor | None = None, |
| 263 | spec_step_idx: int = 0, |
| 264 | ) -> torch.Tensor: |
| 265 | if inputs_embeds is None: |
| 266 | inputs_embeds = self.embed_tokens(input_ids) |
| 267 | current_step_idx = spec_step_idx % self.num_mtp_layers |
| 268 | return self.layers[str(self.mtp_start_layer_idx + current_step_idx)]( |
| 269 | input_ids, |
| 270 | positions, |
| 271 | previous_hidden_states, |
| 272 | inputs_embeds, |
| 273 | current_step_idx, |
| 274 | ) |
| 275 | |
| 276 | def compute_logits( |
| 277 | self, |
| 278 | hidden_states: torch.Tensor, |
| 279 | spec_step_idx: int = 0, |
| 280 | ) -> torch.Tensor: |
| 281 | current_step_idx = spec_step_idx % self.num_mtp_layers |
| 282 | mtp_layer = self.layers[str(self.mtp_start_layer_idx + current_step_idx)] |
| 283 | # MTP forward returns the pre-hc_head residual (T, hc_mult * D); apply |
| 284 | # hc_head here so logits are computed from the dense hidden state. |
| 285 | hidden_states = hidden_states.view( |
| 286 | -1, mtp_layer.hc_mult, mtp_layer.config.hidden_size |
| 287 | ) |
| 288 | hidden_states = hc_head_fused_kernel_tilelang( |
| 289 | hidden_states, |
| 290 | mtp_layer.hc_head_fn, |
| 291 | mtp_layer.hc_head_scale, |
| 292 | mtp_layer.hc_head_base, |
| 293 | mtp_layer.rms_norm_eps, |
| 294 | mtp_layer.hc_eps, |
| 295 | ) |
| 296 | hidden_states = _MTP_SHARED_HEAD_RMSNORM_KERNEL( |
| 297 | hidden_states, |
| 298 | mtp_layer.shared_head.norm.weight.data, |
| 299 | mtp_layer.shared_head.norm.variance_epsilon, |
| 300 | ) |
| 301 | logits = self.logits_processor(mtp_layer.shared_head.head, hidden_states) |
| 302 | return logits |
| 303 | |
| 304 | |
| 305 | class DeepSeekV4MTP(nn.Module): |
| 306 | def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""): |
| 307 | super().__init__() |
| 308 | self.config = vllm_config.model_config.hf_config |
| 309 | self.quant_config = vllm_config.quant_config |
| 310 | self.pad_shared_expert = getattr( |
| 311 | self.quant_config, "weight_block_size", None |
| 312 | ) is not None and not _use_sequence_parallel(vllm_config) |
| 313 | self.model = DeepSeekV4MultiTokenPredictor( |
| 314 | vllm_config=vllm_config, prefix=maybe_prefix(prefix, "model") |
| 315 | ) |
| 316 | |
| 317 | def embed_input_ids(self, input_ids: torch.Tensor) -> torch.Tensor: |
| 318 | return self.model.embed_input_ids(input_ids) |
| 319 | |
| 320 | def forward( |
| 321 | self, |
| 322 | input_ids: torch.Tensor | None, |
| 323 | positions: torch.Tensor, |
| 324 | hidden_states: torch.Tensor, |
| 325 | intermediate_tensors: IntermediateTensors | None = None, |
| 326 | inputs_embeds: torch.Tensor | None = None, |
| 327 | spec_step_idx: int = 0, |
| 328 | ) -> torch.Tensor: |
| 329 | hidden_states = self.model( |
| 330 | input_ids, positions, hidden_states, inputs_embeds, spec_step_idx |
| 331 | ) |
| 332 | return hidden_states |
| 333 | |
| 334 | def compute_logits( |
| 335 | self, |
| 336 | hidden_states: torch.Tensor, |
| 337 | spec_step_idx: int = 0, |
| 338 | ) -> torch.Tensor | None: |
| 339 | return self.model.compute_logits(hidden_states, spec_step_idx) |
| 340 | |
| 341 | def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]) -> set[str]: |
| 342 | # Weight name remapping for checkpoint compatibility. |
| 343 | # Maps checkpoint weight paths to model parameter paths. |
| 344 | WEIGHT_NAME_REMAPPING: dict[str, str] = { |
| 345 | ".emb.tok_emb.weight": ".embed_tokens.weight", |
| 346 | ".head.weight": ".shared_head.head.weight", |
| 347 | ".norm.weight": ".shared_head.norm.weight", |
| 348 | } |
| 349 | |
| 350 | def _remap_weight_name(name: str) -> str: |
| 351 | """Remap checkpoint weight names to model parameter names.""" |
| 352 | for old_pattern, new_pattern in WEIGHT_NAME_REMAPPING.items(): |
| 353 | if old_pattern in name: |
| 354 | name = name.replace(old_pattern, new_pattern) |
| 355 | return name |
| 356 | |
| 357 | def _find_mtp_layer_idx(name: str) -> int: |
| 358 | subnames = name.split(".") |
| 359 | for subname in subnames: |
| 360 | try: |
| 361 | # we return the first encountered integer |
| 362 | return int(subname) |
| 363 | except ValueError: |
| 364 | continue |
| 365 | return 0 |
| 366 | |
| 367 | stacked_params_mapping = [ |
| 368 | # (param_name, shard_name, shard_id) |
| 369 | ("gate_up_proj", "w1", 0), |
| 370 | ("gate_up_proj", "w3", 1), |
| 371 | ("attn.fused_wqa_wkv", "attn.wq_a", 0), |
| 372 | ("attn.fused_wqa_wkv", "attn.wkv", 1), |
| 373 | ] |
| 374 | params_dict = dict(self.named_parameters()) |
| 375 | loaded_params: set[str] = set() |
| 376 | |
| 377 | # TP for attention |
| 378 | tp_size = get_tensor_model_parallel_world_size() |
| 379 | tp_rank = get_tensor_model_parallel_rank() |
| 380 | n_head = self.config.num_attention_heads |
| 381 | n_local_head = n_head // tp_size |
| 382 | head_rank_start = n_local_head * tp_rank |
| 383 | head_rank_end = n_local_head * (tp_rank + 1) |
| 384 | |
| 385 | # Pre-compute expert mapping ONCE. |
| 386 | first_layer = next(iter(self.model.layers.values())) |
| 387 | if first_layer.mtp_block.ffn.use_mega_moe: |
| 388 | expert_mapping = make_deepseek_v4_expert_params_mapping( |
| 389 | self.config.n_routed_experts |
| 390 | ) |
| 391 | else: |
| 392 | expert_mapping = fused_moe_make_expert_params_mapping( |
| 393 | self, |
| 394 | ckpt_gate_proj_name="w1", |
| 395 | ckpt_down_proj_name="w2", |
| 396 | ckpt_up_proj_name="w3", |
| 397 | num_experts=self.config.n_routed_experts, |
| 398 | ) |
| 399 | |
| 400 | # FP8 experts register ``..._weight_scale_inv`` (block_quant) while |
| 401 | # FP4/MXFP4 experts register ``..._weight_scale``. Choose the suffix |
| 402 | # for the rename below based on the model's expert dtype. |
| 403 | expert_scale_suffix = ( |
| 404 | ".weight_scale" |
| 405 | if getattr(self.config, "expert_dtype", "fp4") == "fp4" |
| 406 | else ".weight_scale_inv" |
| 407 | ) |
| 408 | |
| 409 | for name, loaded_weight in weights: |
| 410 | mtp_layer_idx = _find_mtp_layer_idx(name) |
| 411 | # V4 checkpoints store MTP weights as `mtp.{i}.*`; remap to |
| 412 | # `model.layers.{num_hidden_layers + i}.*` so that |
| 413 | # get_spec_layer_idx_from_weight_name can identify them. |
| 414 | name = name.replace( |
| 415 | f"mtp.{mtp_layer_idx}.", |
| 416 | f"model.layers.{self.config.num_hidden_layers + mtp_layer_idx}.", |
| 417 | ) |
| 418 | |
| 419 | spec_layer = get_spec_layer_idx_from_weight_name(self.config, name) |
| 420 | if spec_layer is None: |
| 421 | continue |
| 422 | |
| 423 | name = _remap_weight_name(name) |
| 424 | name = self._rewrite_spec_layer_name(spec_layer, name) |
| 425 | |
| 426 | if spec_layer != self.model.mtp_start_layer_idx and ".layers" not in name: |
| 427 | continue |
| 428 | if name.endswith(".scale"): |
| 429 | suffix = ( |
| 430 | expert_scale_suffix |
| 431 | if _EXPERT_SCALE_RE.search(name) |
| 432 | else ".weight_scale_inv" |
| 433 | ) |
| 434 | name = name.removesuffix(".scale") + suffix |
| 435 | if ".shared_experts.w2" in name: |
| 436 | name = name.replace(".shared_experts.w2", ".shared_experts.down_proj") |
| 437 | if self.pad_shared_expert and ".shared_experts." in name: |
| 438 | loaded_weight = DeepseekV4Model._pad_shared_expert_weight( |
| 439 | self.quant_config, name, loaded_weight |
| 440 | ) |
| 441 | for param_name, weight_name, shard_id in stacked_params_mapping: |
| 442 | # Skip non-stacked layers and experts (experts handled below). |
| 443 | if ".experts." in name: |
| 444 | continue |
| 445 | if weight_name not in name: |
| 446 | continue |
| 447 | name = name.replace(weight_name, param_name) |
| 448 | |
| 449 | param = params_dict[name] |
| 450 | weight_loader = param.weight_loader |
| 451 | weight_loader(param, loaded_weight, shard_id) |
| 452 | loaded_params.add(name) |
| 453 | break |
| 454 | else: |
| 455 | if ".experts." in name: |
| 456 | # Reinterpret E8M0 scales as uint8 to preserve raw |
| 457 | # exponent bytes; numeric copy_() would zero them. |
| 458 | # Mirrors the main DeepseekV4 loader. |
| 459 | if ( |
| 460 | "weight_scale" in name |
| 461 | and loaded_weight.dtype == torch.float8_e8m0fnu |
| 462 | ): |
| 463 | loaded_weight = loaded_weight.view(torch.uint8) |
| 464 | for mapping in expert_mapping: |
| 465 | param_name, weight_name, expert_id, expert_shard_id = mapping |
| 466 | if weight_name not in name: |
| 467 | continue |
| 468 | name_mapped = name.replace(weight_name, param_name) |
| 469 | param = params_dict[name_mapped] |
| 470 | # We should ask the weight loader to return success or not |
| 471 | # here since otherwise we may skip experts with other |
| 472 | # available replicas. |
| 473 | weight_loader = typing.cast( |
| 474 | Callable[..., bool], param.weight_loader |
| 475 | ) |
| 476 | success = weight_loader( |
| 477 | param, |
| 478 | loaded_weight, |
| 479 | name_mapped, |
| 480 | shard_id=expert_shard_id, |
| 481 | expert_id=expert_id, |
| 482 | return_success=True, |
| 483 | ) |
| 484 | if success: |
| 485 | name = name_mapped |
| 486 | loaded_params.add(name_mapped) |
| 487 | break |
| 488 | continue |
| 489 | elif "attn_sink" in name: |
| 490 | narrow_weight = loaded_weight[head_rank_start:head_rank_end] |
| 491 | n = narrow_weight.shape[0] |
| 492 | params_dict[name][:n].copy_(narrow_weight) |
| 493 | loaded_params.add(name) |
| 494 | continue |
| 495 | else: |
| 496 | if name.endswith(".ffn.gate.bias"): |
| 497 | # ``e_score_correction_bias`` lives on the gate |
| 498 | # under a different attribute name. |
| 499 | name = name.replace( |
| 500 | ".ffn.gate.bias", |
| 501 | ".ffn.gate.e_score_correction_bias", |
| 502 | ) |
| 503 | param = params_dict[name] |
| 504 | weight_loader = getattr( |
| 505 | param, "weight_loader", default_weight_loader |
| 506 | ) |
| 507 | weight_loader(param, loaded_weight) |
| 508 | loaded_params.add(name) |
| 509 | continue |
| 510 | |
| 511 | loaded_layers: set[int] = set() |
| 512 | for param_name in loaded_params: |
| 513 | spec_layer = get_spec_layer_idx_from_weight_name(self.config, param_name) |
| 514 | if spec_layer is not None: |
| 515 | loaded_layers.add(spec_layer) |
| 516 | for layer_idx in range( |
| 517 | self.model.mtp_start_layer_idx, |
| 518 | self.model.mtp_start_layer_idx + self.model.num_mtp_layers, |
| 519 | ): |
| 520 | if layer_idx not in loaded_layers and is_mtp_completeness_check_enabled(): |
| 521 | raise ValueError( |
| 522 | f"MTP speculative decoding layer {layer_idx} weights " |
| 523 | f"missing from checkpoint. The checkpoint may have " |
| 524 | f"been quantized without including the MTP layers. " |
| 525 | f"Use a checkpoint that includes MTP layer weights, " |
| 526 | f"or disable speculative decoding." |
| 527 | ) |
| 528 | self.process_weights_after_loading() |
| 529 | logger.info_once("MTP draft model loaded: %d params", len(loaded_params)) |
| 530 | return loaded_params |
| 531 | |
| 532 | def finalize_mega_moe_weights(self) -> None: |
| 533 | for layer in self.model.layers.values(): |
| 534 | layer.mtp_block.ffn.finalize_mega_moe_weights() |
| 535 | |
| 536 | def process_weights_after_loading(self) -> None: |
| 537 | self.finalize_mega_moe_weights() |
| 538 | |
| 539 | def _rewrite_spec_layer_name(self, spec_layer: int, name: str) -> str: |
| 540 | """Rewrite the weight name to match the format of the original model. |
| 541 | Add .mtp_block for modules in transformer layer block for spec layer |
| 542 | and rename shared layer weights to be top level. |
| 543 | """ |
| 544 | spec_layer_weight_names = [ |
| 545 | "embed_tokens", |
| 546 | "enorm", |
| 547 | "hnorm", |
| 548 | "h_proj", |
| 549 | "e_proj", |
| 550 | "shared_head", |
| 551 | "hc_head_fn", |
| 552 | "hc_head_base", |
| 553 | "hc_head_scale", |
| 554 | ] |
| 555 | shared_weight_names = ["embed_tokens"] |
| 556 | spec_layer_weight = False |
| 557 | shared_weight = False |
| 558 | for weight_name in spec_layer_weight_names: |
| 559 | if weight_name in name: |
| 560 | spec_layer_weight = True |
| 561 | if weight_name in shared_weight_names: |
| 562 | shared_weight = True |
| 563 | break |
| 564 | if not spec_layer_weight: |
| 565 | # treat rest weights as weights for transformer layer block |
| 566 | name = name.replace( |
| 567 | f"model.layers.{spec_layer}.", f"model.layers.{spec_layer}.mtp_block." |
| 568 | ) |
| 569 | elif shared_weight: |
| 570 | # treat shared weights as top level weights |
| 571 | name = name.replace(f"model.layers.{spec_layer}.", "model.") |
| 572 | return name |