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1 # SPDX-License-Identifier: Apache-2.0
2 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
3 from typing import TYPE_CHECKING, ClassVar, cast
4
5 import torch
6 import torch.nn as nn
7 from transformers import DeepseekV2Config, DeepseekV3Config
8
9 from vllm.compilation.breakable_cudagraph import eager_break_during_capture
10 from vllm.config import CacheConfig, CUDAGraphMode, VllmConfig
11 from vllm.distributed import get_tensor_model_parallel_world_size
12 from vllm.distributed.parallel_state import get_tp_group
13 from vllm.forward_context import get_forward_context
14 from vllm.model_executor.layers.attention import MLAAttention
15 from vllm.model_executor.layers.attention.attention import get_attention_context
16 from vllm.model_executor.layers.layernorm import LayerNorm, RMSNorm
17 from vllm.model_executor.layers.linear import (
18 ColumnParallelLinear,
19 MergedColumnParallelLinear,
20 ReplicatedLinear,
21 RowParallelLinear,
22 )
23 from vllm.model_executor.layers.quantization import QuantizationConfig
24 from vllm.model_executor.layers.rotary_embedding import get_rope
25 from vllm.model_executor.layers.sparse_attn_indexer import (
26 SparseAttnIndexer,
27 sparse_attn_indexer,
28 )
29 from vllm.model_executor.models.deepseek_v2 import (
30 DeepSeekV2FusedQkvAProjLinear,
31 DeepseekV32IndexerCache,
32 yarn_get_mscale,
33 )
34 from vllm.model_executor.models.utils import extract_layer_index
35 from vllm.models.deepseek_v32.common.kernels import fused_norm_rope, fused_q
36 from vllm.platforms import current_platform
37 from vllm.utils.torch_utils import is_quantized_kv_cache
38 from vllm.v1.attention.ops.pcp import (
39 finalize_mla_pcp_decode,
40 maybe_gather_mla_latent_cache_inputs,
41 )
42
43 if TYPE_CHECKING:
44 from vllm.model_executor.layers.attention.mla_attention import MLACommonMetadata
45 from vllm.v1.attention.backends.mla.index_group import (
46 SparseMLAIndexGroupBuilder,
47 )
48
49
50 class DeepseekV32Indexer(nn.Module):
51 indexer_cache_cls = DeepseekV32IndexerCache
52
53 def __init__(
54 self,
55 vllm_config: VllmConfig,
56 config: DeepseekV2Config | DeepseekV3Config,
57 hidden_size: int,
58 q_lora_rank: int,
59 quant_config: QuantizationConfig | None,
60 cache_config: CacheConfig | None,
61 topk_indices_buffer: torch.Tensor | None,
62 prefix: str = "",
63 ):
64 super().__init__()
65 self.topk_tokens = config.index_topk
66 self.n_head = config.index_n_heads
67 self.head_dim = config.index_head_dim
68 self.rope_dim = config.qk_rope_head_dim
69 self.q_lora_rank = q_lora_rank
70
71 self.wq_b = ReplicatedLinear(
72 self.q_lora_rank,
73 self.head_dim * self.n_head,
74 bias=False,
75 quant_config=quant_config,
76 prefix=f"{prefix}.wq_b",
77 )
78
79 self.wk_weights_proj = MergedColumnParallelLinear(
80 hidden_size,
81 [self.head_dim, self.n_head],
82 bias=False,
83 quant_config=None,
84 disable_tp=True,
85 prefix=f"{prefix}.wk_weights_proj",
86 )
87 self.k_norm = LayerNorm(self.head_dim, eps=1e-6, dtype=torch.float32)
88 self.softmax_scale = self.head_dim**-0.5
89
90 self.scale_fmt = "ue8m0"
91 self.quant_block_size = 128
92 self.topk_indices_buffer = topk_indices_buffer
93
94 assert cache_config is not None, "DeepSeek V3.2 indexer requires cache_config"
95 self.k_cache = type(self).indexer_cache_cls(
96 head_dim=self.head_dim + self.head_dim // self.quant_block_size * 4,
97 dtype=torch.uint8,
98 prefix=f"{prefix}.k_cache",
99 cache_config=cache_config,
100 )
101 self.max_model_len = vllm_config.model_config.max_model_len
102 self.prefix = prefix
103
104 from vllm.v1.attention.backends.mla.indexer import (
105 get_max_prefill_buffer_size,
106 )
107
108 self.max_total_seq_len = get_max_prefill_buffer_size(vllm_config)
109 self.indexer_op = SparseAttnIndexer(
110 self.k_cache,
111 self.quant_block_size,
112 self.scale_fmt,
113 self.topk_tokens,
114 self.head_dim,
115 self.max_model_len,
116 self.max_total_seq_len,
117 self.topk_indices_buffer,
118 )
119
120
121 class DeepseekV32Attention(MLAAttention):
122 indexer: "DeepseekV32Indexer | None"
123 indexer_cls: "type[DeepseekV32Indexer]" = DeepseekV32Indexer
124 supports_pcp_dcp: ClassVar[bool] = True
125
126 def __init__(
127 self,
128 vllm_config: VllmConfig,
129 config: DeepseekV2Config | DeepseekV3Config,
130 prefix: str,
131 topk_indices_buffer: torch.Tensor | None = None,
132 attn_backend: "type | None" = None,
133 index_group_builder: "SparseMLAIndexGroupBuilder | None" = None,
134 ) -> None:
135 quant_config = vllm_config.quant_config
136 cache_config = vllm_config.cache_config
137
138 hidden_size = config.hidden_size
139 qk_nope_head_dim = config.qk_nope_head_dim
140 qk_rope_head_dim = config.qk_rope_head_dim
141 v_head_dim = config.v_head_dim
142 q_lora_rank = config.q_lora_rank
143 kv_lora_rank = config.kv_lora_rank
144 num_heads = config.num_attention_heads
145
146 tp_size = get_tensor_model_parallel_world_size()
147 assert num_heads % tp_size == 0
148 num_local_heads = num_heads // tp_size
149 qk_head_dim = qk_nope_head_dim + qk_rope_head_dim
150 scaling = qk_head_dim**-0.5
151 max_position_embeddings = getattr(config, "max_position_embeddings", 8192)
152
153 # DSA checkpoints may use plain ("default") or yarn-scaled RoPE.
154 if config.rope_parameters["rope_type"] != "default":
155 config.rope_parameters["rope_type"] = (
156 "deepseek_llama_scaling"
157 if config.rope_parameters.get("attention_factor") == 1.0
158 else "deepseek_yarn"
159 )
160 if config.rope_parameters["rope_type"] == "deepseek_yarn":
161 mscale_all_dim = config.rope_parameters.get("mscale_all_dim", False)
162 scaling_factor = config.rope_parameters["factor"]
163 mscale = yarn_get_mscale(scaling_factor, float(mscale_all_dim))
164 scaling = scaling * mscale * mscale
165
166 layer_id = extract_layer_index(prefix)
167 index_topk_freq = getattr(config, "index_topk_freq", 1)
168 index_topk_pattern = getattr(config, "index_topk_pattern", None)
169 index_skip_topk_offset = getattr(config, "index_skip_topk_offset", 2)
170 if index_topk_pattern is None:
171 skip_topk = (
172 max(layer_id - index_skip_topk_offset + 1, 0) % index_topk_freq != 0
173 )
174 elif 0 <= layer_id < len(index_topk_pattern):
175 skip_topk = index_topk_pattern[layer_id] == "S"
176 else:
177 skip_topk = False
178
179 num_hidden_layers = getattr(config, "num_hidden_layers", None)
180 is_mtp_layer = num_hidden_layers is not None and layer_id >= num_hidden_layers
181
182 kv_b_proj = ColumnParallelLinear(
183 kv_lora_rank,
184 num_heads * (qk_nope_head_dim + v_head_dim),
185 bias=False,
186 quant_config=quant_config,
187 prefix=f"{prefix}.kv_b_proj",
188 )
189 indexer = None
190 if not skip_topk or is_mtp_layer:
191 indexer = type(self).indexer_cls(
192 vllm_config,
193 config,
194 hidden_size,
195 q_lora_rank,
196 quant_config,
197 cache_config,
198 topk_indices_buffer,
199 prefix=f"{prefix}.indexer",
200 )
201
202 super().__init__(
203 num_heads=num_local_heads,
204 scale=scaling,
205 qk_nope_head_dim=qk_nope_head_dim,
206 qk_rope_head_dim=qk_rope_head_dim,
207 v_head_dim=v_head_dim,
208 q_lora_rank=q_lora_rank,
209 kv_lora_rank=kv_lora_rank,
210 kv_b_proj=kv_b_proj,
211 cache_config=cache_config,
212 quant_config=quant_config,
213 prefix=f"{prefix}.attn",
214 use_sparse=True,
215 indexer=indexer,
216 topk_indices_buffer=topk_indices_buffer,
217 index_group_builder=index_group_builder,
218 attn_backend=attn_backend,
219 )
220
221 self.num_local_heads = num_local_heads
222 self.qk_head_dim = qk_head_dim
223 self.indexer = indexer
224 self.topk_indices_buffer = topk_indices_buffer
225
226 self.skip_topk = False
227 enable_short_prefill_scoring_skip = (
228 not is_mtp_layer
229 and not skip_topk
230 and not self.use_pcp
231 and current_platform.is_cuda()
232 and self.supports_dense_mha_prefill
233 )
234 self._dense_mha_metadata_layer_name = (
235 self.layer_name if enable_short_prefill_scoring_skip else ""
236 )
237
238 fp8_attention = is_quantized_kv_cache(self.kv_cache_dtype)
239 self._fp8_query = fp8_attention and self.impl.supports_quant_query_input
240 self._fp8_kv_needs_view = fp8_attention and not self.kv_cache_dtype.endswith(
241 "_ds_mla"
242 )
243
244 self._index_rope_interleave = getattr(config, "indexer_rope_interleave", False)
245
246 # Remaining MLA projections (registered on this module).
247 self.fused_qkv_a_proj = DeepSeekV2FusedQkvAProjLinear(
248 hidden_size,
249 [q_lora_rank, kv_lora_rank + qk_rope_head_dim],
250 quant_config=quant_config,
251 prefix=f"{prefix}.fused_qkv_a_proj",
252 )
253 self.q_a_layernorm = RMSNorm(q_lora_rank, eps=config.rms_norm_eps)
254 self.q_b_proj = ColumnParallelLinear(
255 q_lora_rank,
256 num_heads * qk_head_dim,
257 bias=False,
258 quant_config=quant_config,
259 prefix=f"{prefix}.q_b_proj",
260 )
261 self.kv_a_layernorm = RMSNorm(kv_lora_rank, eps=config.rms_norm_eps)
262
263 self.o_proj = RowParallelLinear(
264 num_heads * v_head_dim,
265 hidden_size,
266 bias=False,
267 reduce_results=False,
268 quant_config=quant_config,
269 prefix=f"{prefix}.o_proj",
270 )
271
272 self.rotary_emb = get_rope(
273 qk_rope_head_dim,
274 max_position=max_position_embeddings,
275 rope_parameters=config.rope_parameters,
276 is_neox_style=False,
277 )
278 # Lightning indexer uses its own RoPE; interleave maps to non-NeoX.
279 self.indexer_rope_emb = get_rope(
280 qk_rope_head_dim,
281 max_position=max_position_embeddings,
282 rope_parameters=config.rope_parameters,
283 is_neox_style=not getattr(config, "indexer_rope_interleave", False),
284 )
285
286 def _should_prepare_mqa_query(
287 self,
288 attn_metadata: "MLACommonMetadata | None",
289 cudagraph_runtime_mode: CUDAGraphMode,
290 ) -> bool:
291 return (
292 attn_metadata is None
293 or not self._use_sparse_mha(attn_metadata)
294 or cudagraph_runtime_mode == CUDAGraphMode.FULL
295 or torch.cuda.is_current_stream_capturing()
296 )
297
298 def forward( # type: ignore[override]
299 self,
300 positions: torch.Tensor,
301 hidden_states: torch.Tensor,
302 ) -> torch.Tensor:
303 # Captured: A-projections (+ indexer A-GEMM on indexer layers).
304 qkv_lora = self.fused_qkv_a_proj(hidden_states)[0]
305 q_c, kv_c, k_pe = qkv_lora.split(
306 [self.q_lora_rank, self.kv_lora_rank, self.qk_rope_head_dim], dim=-1
307 )
308
309 if self.indexer is not None and not self.skip_topk:
310 kw = self.indexer.wk_weights_proj(hidden_states)[0]
311 index_k = kw[:, : self.indexer.head_dim]
312 index_weights = kw[:, self.indexer.head_dim :]
313 else:
314 index_k = None
315 index_weights = None
316
317 num_tokens = hidden_states.shape[0]
318 output = torch.empty(
319 (num_tokens, self.num_local_heads * self.v_head_dim),
320 dtype=hidden_states.dtype,
321 device=hidden_states.device,
322 )
323 forward_context = get_forward_context()
324 slot_mapping = forward_context.slot_mapping
325 assert isinstance(slot_mapping, dict)
326 mla_slot = slot_mapping.get(self.layer_name)
327 indexer_slot = (
328 slot_mapping.get(self.indexer.k_cache.prefix)
329 if self.indexer is not None
330 else None
331 )
332 hisparse_cache = self.hisparse_cache
333 layer_attn_metadata, _, _, _ = get_attention_context(self.layer_name)
334 self.impl.prepare_for_batch(layer_attn_metadata)
335
336 prepare_mqa_query = self._should_prepare_mqa_query(
337 layer_attn_metadata, forward_context.cudagraph_runtime_mode
338 )
339 if self.indexer is not None and not self.skip_topk:
340 has_indexer = True
341 indexer_k_norm_w = self.indexer.k_norm.weight
342 indexer_k_norm_bias = self.indexer.k_norm.bias
343 indexer_k_norm_eps = self.indexer.k_norm.eps
344 indexer_k_rope_cos_sin_cache = self.indexer_rope_emb.cos_sin_cache
345 indexer_cache_shuffled = self.indexer.k_cache.uses_shuffled_layout
346 indexer_k_cache = None if self.use_pcp else self.indexer.k_cache.kv_cache
347 index_k_out = torch.empty_like(index_k) if self.use_pcp else None
348 indexer_softmax_scale = self.indexer.softmax_scale
349 indexer_n_head_scale = self.indexer.n_head**-0.5
350 else:
351 has_indexer = False
352 indexer_k_norm_w = None
353 indexer_k_norm_bias = None
354 indexer_k_norm_eps = 1e-6
355 indexer_k_rope_cos_sin_cache = None
356 indexer_k_cache = None
357 indexer_cache_shuffled = False
358 index_k_out = None
359 indexer_softmax_scale = 0.0
360 indexer_n_head_scale = 0.0
361
362 if forward_context.attn_metadata is None or self.use_pcp:
363 mla_kv_cache = None
364 mla_k_scale = None
365 indexer_k_cache = None
366 mla_slot = None
367 indexer_slot = None
368 else:
369 mla_kv_cache = None if hisparse_cache is not None else self.kv_cache
370 mla_k_scale = self._k_scale
371
372 if self.use_pcp or hisparse_cache is None:
373 kv_c_out = torch.empty_like(kv_c)
374 k_pe_out = torch.empty_like(k_pe)
375 else:
376 kv_c_out = torch.empty_like(kv_c)
377 k_pe_out = torch.empty_like(k_pe)
378 q_c = fused_norm_rope(
379 positions,
380 q_c,
381 self.q_a_layernorm.weight,
382 self.q_a_layernorm.variance_epsilon,
383 kv_c,
384 self.kv_a_layernorm.weight,
385 self.kv_a_layernorm.variance_epsilon,
386 k_pe,
387 self.rotary_emb.cos_sin_cache,
388 index_k,
389 indexer_k_norm_w,
390 indexer_k_norm_bias,
391 indexer_k_norm_eps,
392 indexer_k_rope_cos_sin_cache,
393 self.topk_indices_buffer,
394 slot_mapping=mla_slot,
395 indexer_slot_mapping=indexer_slot,
396 indexer_k_cache=indexer_k_cache,
397 indexer_cache_shuffled=indexer_cache_shuffled,
398 mla_kv_cache=mla_kv_cache,
399 mla_kv_cache_dtype=self.kv_cache_dtype,
400 mla_k_scale=mla_k_scale,
401 has_indexer=has_indexer,
402 index_rope_interleave=self._index_rope_interleave,
403 kv_c_out=kv_c_out,
404 k_pe_out=k_pe_out,
405 index_k_out=index_k_out,
406 )
407
408 if hisparse_cache is not None and mla_slot is not None:
409 assert kv_c_out is not None and k_pe_out is not None
410 self.update_kv_cache(
411 kv_c_out,
412 k_pe_out,
413 self.kv_cache,
414 mla_slot,
415 layer_attn_metadata,
416 self.kv_cache_dtype,
417 self._k_scale,
418 )
419
420 q = self.q_b_proj(q_c)[0].view(-1, self.num_local_heads, self.qk_head_dim)
421 q_nope, q_pe = q.split([self.qk_nope_head_dim, self.qk_rope_head_dim], dim=-1)
422 if prepare_mqa_query:
423 ql_nope = torch.bmm(q_nope.transpose(0, 1), self.W_UK_T).transpose(0, 1)
424 else:
425 ql_nope = q_nope
426
427 if self.indexer is not None and not self.skip_topk:
428 index_q = self.indexer.wq_b(q_c)[0]
429 index_q = index_q.view(-1, self.indexer.n_head, self.indexer.head_dim)
430 else:
431 index_q = None
432
433 index_q_fp8, index_weights_out, mqa_q = fused_q(
434 positions,
435 q_pe,
436 self.rotary_emb.cos_sin_cache,
437 index_q,
438 self.indexer_rope_emb.cos_sin_cache if has_indexer else None,
439 ql_nope,
440 self._q_scale,
441 index_weights,
442 indexer_softmax_scale,
443 indexer_n_head_scale,
444 has_indexer=has_indexer,
445 index_rope_interleave=self._index_rope_interleave,
446 quantize_mqa=self._fp8_query and prepare_mqa_query,
447 )
448
449 self._sparse_indexer_and_attn(
450 positions,
451 q_c,
452 q_nope,
453 q_pe,
454 index_q_fp8,
455 index_k_out,
456 index_weights_out,
457 kv_c_out,
458 k_pe_out,
459 ql_nope,
460 mqa_q,
461 output,
462 )
463 return self.o_proj(output)[0]
464
465 @eager_break_during_capture
466 def _sparse_indexer_and_attn(
467 self,
468 positions: torch.Tensor,
469 q_c: torch.Tensor,
470 q_nope: torch.Tensor,
471 q_pe: torch.Tensor,
472 index_q_fp8: torch.Tensor | None,
473 index_k: torch.Tensor | None,
474 index_weights_out: torch.Tensor | None,
475 kv_c: torch.Tensor | None,
476 k_pe: torch.Tensor | None,
477 ql_nope: torch.Tensor,
478 mqa_q: torch.Tensor,
479 output: torch.Tensor,
480 ) -> None:
481 if self.indexer is not None and not self.skip_topk:
482 assert index_q_fp8 is not None
483 assert index_weights_out is not None
484 if self.use_pcp:
485 assert index_k is not None
486 sparse_attn_indexer(
487 q_c,
488 self.indexer.k_cache.prefix,
489 self.indexer.k_cache.kv_cache,
490 index_q_fp8,
491 None,
492 index_k,
493 index_weights_out,
494 self.indexer.quant_block_size,
495 self.indexer.scale_fmt,
496 self.indexer.topk_tokens,
497 self.indexer.head_dim,
498 self.indexer.max_model_len,
499 self.indexer.max_total_seq_len,
500 self.topk_indices_buffer,
501 skip_k_cache_insert=not self.use_pcp,
502 use_pcp=self.use_pcp,
503 pcp_shard_decode_requests=self.pcp_shard_decode_requests,
504 dense_mha_metadata_layer_name=self._dense_mha_metadata_layer_name,
505 dcp_rank=(
506 self.dcp_manager.group.rank_in_group
507 if self.dcp_manager is not None
508 else 0
509 ),
510 dcp_world_size=(
511 self._vllm_config.parallel_config.decode_context_parallel_size
512 ),
513 cp_kv_cache_interleave_size=(
514 self._vllm_config.parallel_config.cp_kv_cache_interleave_size
515 ),
516 skip_topk_buffer_clear=True,
517 topk_backend=self.indexer.indexer_op.topk_backend,
518 )
519 self.impl.record_logical_topk_ready() # type: ignore[attr-defined]
520
521 attn_metadata, _, kv_cache, layer_slot_mapping = get_attention_context(
522 self.layer_name
523 )
524 if attn_metadata is None:
525 output.zero_()
526 return
527 attn_metadata = cast("MLACommonMetadata", attn_metadata)
528 self.impl.prepare_for_batch(attn_metadata)
529
530 if self.use_pcp:
531 assert kv_c is not None and k_pe is not None
532 kv_for_cache, kpe_for_cache, cache_slot_mapping = (
533 maybe_gather_mla_latent_cache_inputs(
534 kv_c,
535 k_pe.unsqueeze(1),
536 layer_slot_mapping,
537 attn_metadata.num_decode_tokens,
538 True,
539 pcp_shard_decode_requests=self.pcp_shard_decode_requests,
540 )
541 )
542 self.impl.do_kv_cache_update( # type: ignore[attr-defined]
543 kv_for_cache,
544 kpe_for_cache,
545 kv_cache,
546 cache_slot_mapping,
547 self.kv_cache_dtype,
548 self._k_scale,
549 )
550
551 num_actual = attn_metadata.num_actual_tokens # type: ignore[attr-defined]
552 if num_actual == 0:
553 output.zero_()
554 return
555
556 if self._use_sparse_mha(attn_metadata):
557 assert kv_c is not None and k_pe is not None
558 mha_q_pe = (
559 self.rotary_emb(positions, q_pe)[0]
560 if mqa_q.dtype != q_pe.dtype
561 else mqa_q
562 )
563 mha_q = torch.cat((q_nope, mha_q_pe), dim=-1)
564 self.forward_impl(
565 mha_q,
566 kv_c,
567 k_pe.unsqueeze(1),
568 kv_cache,
569 attn_metadata,
570 output,
571 )
572 return
573
574 if self._fp8_kv_needs_view:
575 kv_cache = kv_cache.view(current_platform.fp8_dtype())
576 if self._fp8_query:
577 # FlashInfer sparse: single packed fp8 query.
578 mqa_q_arg: torch.Tensor | tuple[torch.Tensor, torch.Tensor] = mqa_q[
579 :num_actual
580 ]
581 else:
582 mqa_q_arg = (ql_nope[:num_actual], mqa_q[:num_actual])
583
584 if self.use_pcp and self.impl.dcp_world_size > self.impl.pcp_world_size:
585 if isinstance(mqa_q_arg, tuple):
586 mqa_q_arg = torch.cat(mqa_q_arg, dim=-1)
587 mqa_q_arg = get_tp_group().all_gather(mqa_q_arg, dim=1)
588 elif not self.use_pcp and self.impl.dcp_world_size > 1:
589 assert self.dcp_manager is not None
590 if isinstance(mqa_q_arg, tuple):
591 mqa_q_arg = torch.cat(mqa_q_arg, dim=-1)
592 assert self.dcp_manager.query_gather is not None
593 mqa_q_arg = self.dcp_manager.query_gather(mqa_q_arg)
594 attn_out, lse = self.impl.forward_mqa( # type: ignore[attr-defined]
595 mqa_q_arg, kv_cache, attn_metadata, self
596 )
597
598 if self.impl.dcp_world_size > 1:
599 assert lse is not None and self.dcp_manager is not None
600 seq_lens: torch.Tensor | None
601 query_start_loc: torch.Tensor | None
602 if self.use_pcp:
603 decode_metadata = getattr(attn_metadata, "decode", None)
604 if decode_metadata is not None:
605 seq_lens = decode_metadata.seq_lens
606 else:
607 all_seq_lens = cast(
608 torch.Tensor,
609 attn_metadata.seq_lens, # type: ignore[attr-defined]
610 )
611 seq_lens = all_seq_lens[: attn_metadata.num_decodes]
612 query_start_loc = attn_metadata.query_start_loc[
613 : attn_metadata.num_decodes + 1
614 ]
615 else:
616 # The backend emits (0, -inf) for empty local shards, so no
617 # PCP-only empty-shard metadata is needed.
618 seq_lens = None
619 query_start_loc = None
620 # Under PCP+DCP the prefill rows attended over the gathered KV, so
621 # only the decode rows carry an LSE and take part in the merge.
622 num_merge_rows = lse.shape[0]
623 if num_merge_rows == attn_out.shape[0]:
624 attn_out = self.dcp_manager.combine(
625 attn_out,
626 lse,
627 seq_lens=seq_lens, # type: ignore[arg-type]
628 query_start_loc=query_start_loc, # type: ignore[arg-type]
629 )
630 elif num_merge_rows > 0:
631 attn_out[:num_merge_rows] = self.dcp_manager.combine(
632 attn_out[:num_merge_rows],
633 lse,
634 seq_lens=seq_lens, # type: ignore[arg-type]
635 query_start_loc=query_start_loc, # type: ignore[arg-type]
636 )
637 if self.use_pcp:
638 attn_out = finalize_mla_pcp_decode(attn_out, self.num_heads)
639
640 # NOTE(woosuk): While the below does not need to be in the eager region,
641 # we put it here to avoid copying the attention output. Move this back to the
642 # captured region once forward_mqa supports `out` argument.
643 x = attn_out.view(
644 num_actual, self.num_local_heads, self.kv_lora_rank
645 ).transpose(0, 1)
646 out = (
647 output[:num_actual]
648 .view(num_actual, self.num_local_heads, self.v_head_dim)
649 .transpose(0, 1)
650 )
651 torch.bmm(x, self.W_UV, out=out)
652 if self.use_pcp and num_actual < output.shape[0]:
653 output[num_actual:].zero_()