Add Laguna XS.2.1 DFlash drafter support (#46853)
Signed-off-by: Adam Baranowski <adam.baranowski@poolside.ai>
adamkbaranowski committed
Jul 3, 2026 at 03:09 UTC
4c3c64fcf76450d3d0bbfd3d1725eade0f214710
7 files changed
+494
-47
tests/models/registry.py
+7
@@ -1410,6 +1410,13 @@ _SPECULATIVE_DECODING_EXAMPLE_MODELS = {
1410
max_model_len=8192, # Reduce max len to ensure test runs in low-VRAM CI env
1411
max_num_seqs=32,
1412
),
1413
+ "DFlashLagunaForCausalLM": _HfExamplesInfo(
1414
+ "poolside/Laguna-XS-2.1",
1415
+ speculative_model="poolside/Laguna-XS-2.1-DFlash",
1416
+ use_original_num_layers=True,
1417
+ max_model_len=8192, # Reduce max len to ensure test runs in low-VRAM CI env
1418
+ max_num_seqs=32,
1419
+ ),
1420
"DFlashQwen3NextDraftModel": _HfExamplesInfo(
1421
"Qwen/Qwen3-Coder-Next",
1422
speculative_model="z-lab/Qwen3-Coder-Next-DFlash",
tests/v1/e2e/spec_decode/test_laguna_dflash.py
new
+60
@@ -0,0 +1,60 @@
1
+# SPDX-License-Identifier: Apache-2.0
2
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
3
+
4
+import pytest
5
+import torch
6
+
7
+from tests.utils import large_gpu_mark
8
+from vllm import LLM, SamplingParams
9
+from vllm.distributed import cleanup_dist_env_and_memory
10
+
11
+
12
+def _get_counter(metrics, name: str) -> float:
13
+ metric = next((m for m in metrics if m.name == name), None)
14
+ assert metric is not None, f"Missing metric: {name}"
15
+ return metric.value
16
+
17
+
18
+@pytest.mark.slow_test
19
+@large_gpu_mark(min_gb=80)
20
+def test_laguna_dflash_hf_pair_smoke(monkeypatch):
21
+ """Smoke-test the public Laguna XS-2.1 base/DFlash checkpoint pair."""
22
+ monkeypatch.setenv("VLLM_USE_FLASHINFER_SAMPLER", "0")
23
+
24
+ llm = LLM(
25
+ model="poolside/Laguna-XS-2.1",
26
+ trust_remote_code=True,
27
+ speculative_config={
28
+ "method": "dflash",
29
+ "model": "poolside/Laguna-XS-2.1-DFlash",
30
+ "num_speculative_tokens": 15,
31
+ },
32
+ max_model_len=8192,
33
+ max_num_batched_tokens=65536,
34
+ max_num_seqs=32,
35
+ enforce_eager=True,
36
+ disable_log_stats=False,
37
+ )
38
+
39
+ try:
40
+ outputs = llm.generate(
41
+ [
42
+ "What is the capital of the United Kingdom?",
43
+ "Write a Python function that returns the square of a number.",
44
+ ],
45
+ SamplingParams(temperature=0.0, max_tokens=32, ignore_eos=True),
46
+ )
47
+ assert len(outputs) == 2
48
+ assert all(output.outputs[0].text for output in outputs)
49
+
50
+ metrics = llm.get_metrics()
51
+ num_drafts = _get_counter(metrics, "vllm:spec_decode_num_drafts")
52
+ num_accepted = _get_counter(metrics, "vllm:spec_decode_num_accepted_tokens")
53
+
54
+ assert num_drafts > 0
55
+ acceptance_len = 1 + (num_accepted / num_drafts)
56
+ assert acceptance_len > 1.0
57
+ finally:
58
+ del llm
59
+ torch.accelerator.empty_cache()
60
+ cleanup_dist_env_and_memory()
vllm/model_executor/models/laguna.py
+18
-6
@@ -269,8 +269,14 @@ class LagunaAttention(nn.Module):
269
quant_config: QuantizationConfig | None = None,
270
prefix: str = "",
271
attention_sink: bool = False,
272
+ layer_idx: int | None = None,
273
+ attention_prefix: str | None = None,
274
) -> None:
275
super().__init__()
276
+ if layer_idx is None:
277
+ layer_idx = extract_layer_index(prefix)
278
+ if attention_prefix is None:
279
+ attention_prefix = prefix
280
self.hidden_size = hidden_size
281
tp_size = get_tensor_model_parallel_world_size()
282
self.total_num_heads = num_heads
@@ -294,7 +300,6 @@ class LagunaAttention(nn.Module):
300
# Per-layer sliding window (follows Gemma2/Cohere2 convention)
301
layer_types = getattr(config, "layer_types", None)
302
if layer_types is not None:
297
- layer_idx = extract_layer_index(prefix)
303
is_sliding = layer_types[layer_idx] == "sliding_attention"
304
self.sliding_window = config.sliding_window if is_sliding else None
305
else:
@@ -361,9 +366,7 @@ class LagunaAttention(nn.Module):
366
# crash `get_rope`'s cache lookup, so always pull out the layer's
367
# sub-dict before forwarding.
368
layer_type = (
364
- layer_types[extract_layer_index(prefix)]
365
- if layer_types is not None
366
- else "full_attention"
369
+ layer_types[layer_idx] if layer_types is not None else "full_attention"
370
)
371
is_sliding = layer_type == "sliding_attention"
372
@@ -415,7 +418,7 @@ class LagunaAttention(nn.Module):
418
cache_config=cache_config,
419
quant_config=quant_config,
420
per_layer_sliding_window=self.sliding_window,
418
- prefix=f"{prefix}.attn",
421
+ prefix=f"{attention_prefix}.attn",
422
sinks=sinks,
423
)
424
@@ -468,10 +471,13 @@ class LagunaDecoderLayer(nn.Module):
471
quant_config: QuantizationConfig | None = None,
472
prefix: str = "",
473
enable_eplb: bool = False,
474
+ layer_idx: int | None = None,
475
+ attention_prefix: str | None = None,
476
) -> None:
477
super().__init__()
478
self.hidden_size = config.hidden_size
474
- layer_idx = extract_layer_index(prefix)
479
+ if layer_idx is None:
480
+ layer_idx = extract_layer_index(prefix)
481
482
# Determine if this layer uses sliding window attention
483
layer_types = getattr(config, "layer_types", None)
@@ -503,6 +509,12 @@ class LagunaDecoderLayer(nn.Module):
509
quant_config=quant_config,
510
prefix=f"{prefix}.self_attn",
511
attention_sink=attention_sink,
512
+ layer_idx=layer_idx,
513
+ attention_prefix=(
514
+ f"{attention_prefix}.self_attn"
515
+ if attention_prefix is not None
516
+ else None
517
+ ),
518
)
519
520
# Check if this layer uses MoE or dense MLP (matches Qwen2/Qwen3 convention)
vllm/model_executor/models/laguna_dflash.py
new
+342
@@ -0,0 +1,342 @@
1
+# SPDX-License-Identifier: Apache-2.0
2
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
3
+"""DFlash speculator for Laguna target models.
4
+
5
+Laguna DFlash uses a uniform drafter layer flavor (`layer_types` all full
6
+or all sliding). The draft checkpoint shares token embedding and lm_head
7
+weights with the target model through the generic spec-decode proposer.
8
+"""
9
+
10
+from collections.abc import Iterable
11
+
12
+import torch
13
+from torch import nn
14
+
15
+from vllm import _custom_ops as ops
16
+from vllm.compilation.decorators import support_torch_compile
17
+from vllm.config import VllmConfig
18
+from vllm.logger import init_logger
19
+from vllm.model_executor.layers.layernorm import RMSNorm
20
+from vllm.model_executor.layers.linear import ReplicatedLinear
21
+from vllm.model_executor.layers.logits_processor import LogitsProcessor
22
+from vllm.model_executor.layers.vocab_parallel_embedding import (
23
+ ParallelLMHead,
24
+ VocabParallelEmbedding,
25
+)
26
+from vllm.model_executor.model_loader.weight_utils import (
27
+ default_weight_loader,
28
+ maybe_remap_kv_scale_name,
29
+)
30
+from vllm.model_executor.models.interfaces import EagleModelMixin, SupportsEagle3
31
+from vllm.multimodal.inputs import NestedTensors
32
+
33
+from .laguna import LagunaDecoderLayer
34
+from .qwen3_dflash import DFlashQwen3Model
35
+from .utils import (
36
+ AutoWeightsLoader,
37
+ get_draft_quant_config,
38
+ maybe_prefix,
39
+ process_eagle_weight,
40
+)
41
+
42
+logger = init_logger(__name__)
43
+
44
+
45
+def _get_dflash_layer_types(config) -> tuple[str, ...]:
46
+ layer_types = getattr(config, "layer_types", None)
47
+ if layer_types is None:
48
+ raise ValueError("Laguna DFlash config requires `layer_types`.")
49
+ if len(layer_types) != config.num_hidden_layers:
50
+ raise ValueError(
51
+ f"DFlash layer_types length {len(layer_types)} does not match "
52
+ f"num_hidden_layers {config.num_hidden_layers}."
53
+ )
54
+ # Laguna DFlash checkpoints use a uniform drafter attention flavor.
55
+ if len(set(layer_types)) > 1:
56
+ raise NotImplementedError(
57
+ "Laguna DFlash drafter requires a uniform `layer_types` "
58
+ f"(got {sorted(set(layer_types))})."
59
+ )
60
+ return tuple(layer_types)
61
+
62
+
63
+@support_torch_compile
64
+class DFlashLagunaModel(DFlashQwen3Model, EagleModelMixin):
65
+ def __init__(
66
+ self,
67
+ *,
68
+ vllm_config: VllmConfig,
69
+ prefix: str = "",
70
+ ) -> None:
71
+ nn.Module.__init__(self)
72
+ self.config = vllm_config.speculative_config.draft_model_config.hf_config
73
+ self.vocab_size = self.config.vocab_size
74
+ self.quant_config = get_draft_quant_config(vllm_config)
75
+
76
+ target_layer_ids = self.config.dflash_config["target_layer_ids"]
77
+ if not target_layer_ids:
78
+ raise ValueError(
79
+ "Laguna DFlash config requires non-empty "
80
+ "`dflash_config.target_layer_ids`."
81
+ )
82
+
83
+ self.embed_tokens = VocabParallelEmbedding(
84
+ self.config.vocab_size,
85
+ self.config.hidden_size,
86
+ prefix=maybe_prefix(prefix, "embed_tokens"),
87
+ )
88
+
89
+ self.mask_token_id = self.config.dflash_config.get("mask_token_id")
90
+ self.register_buffer(
91
+ "mask_embedding",
92
+ torch.zeros(
93
+ self.config.hidden_size,
94
+ dtype=vllm_config.model_config.dtype,
95
+ ),
96
+ persistent=False,
97
+ )
98
+ self.has_separate_mask_embedding = False
99
+
100
+ self.layer_types = _get_dflash_layer_types(self.config)
101
+ target_layer_count = self.config.target_layer_count
102
+ self.layers = nn.ModuleList(
103
+ [
104
+ LagunaDecoderLayer(
105
+ prefix=maybe_prefix(prefix, f"layers.{layer_idx}"),
106
+ config=self.config,
107
+ cache_config=vllm_config.cache_config,
108
+ quant_config=self.quant_config,
109
+ layer_idx=layer_idx,
110
+ attention_prefix=maybe_prefix(
111
+ prefix, f"layers.{layer_idx + target_layer_count}"
112
+ ),
113
+ )
114
+ for layer_idx in range(self.config.num_hidden_layers)
115
+ ]
116
+ )
117
+ for layer in self.layers:
118
+ if getattr(layer.self_attn, "sliding_window", None) is not None:
119
+ # DFlash inserts verifier-context K/V at absolute cache slots.
120
+ # Keep full KV allocation; SWA remains a compute-time limit.
121
+ layer.self_attn.attn.sliding_window = None
122
+ num_features_to_use = len(target_layer_ids)
123
+ target_hidden_size = vllm_config.model_config.get_hidden_size()
124
+ fc_input_size = target_hidden_size * num_features_to_use
125
+ self.num_aux_slices = num_features_to_use
126
+ self.aux_hidden_norms = nn.ModuleList(
127
+ [
128
+ RMSNorm(
129
+ fc_input_size // num_features_to_use,
130
+ eps=self.config.rms_norm_eps,
131
+ )
132
+ for _ in range(num_features_to_use)
133
+ ]
134
+ )
135
+ self.fc = ReplicatedLinear(
136
+ input_size=fc_input_size,
137
+ output_size=self.config.hidden_size,
138
+ bias=False,
139
+ params_dtype=vllm_config.model_config.dtype,
140
+ quant_config=self.quant_config,
141
+ prefix=maybe_prefix(prefix, "fc"),
142
+ return_bias=False,
143
+ )
144
+ self.hidden_norm = RMSNorm(
145
+ self.config.hidden_size,
146
+ eps=self.config.rms_norm_eps,
147
+ )
148
+ self.norm = RMSNorm(
149
+ self.config.hidden_size,
150
+ eps=self.config.rms_norm_eps,
151
+ )
152
+
153
+ def _build_context_kv_buffers(
154
+ self,
155
+ layers_attn: list[nn.Module],
156
+ has_bias: bool,
157
+ ) -> None:
158
+ self._kv_weights = torch.stack(
159
+ [a.qkv_proj.weight[a.q_size :] for a in layers_attn], dim=0
160
+ ).contiguous()
161
+ if has_bias:
162
+ self._kv_biases: torch.Tensor | None = torch.stack(
163
+ [a.qkv_proj.bias[a.q_size :] for a in layers_attn], dim=0
164
+ ).contiguous()
165
+ else:
166
+ self._kv_biases = None
167
+ self._input_layernorm_weights = torch.stack(
168
+ [layer.input_layernorm.weight.data for layer in self.layers], dim=0
169
+ ).contiguous()
170
+ self._k_norm_weights = torch.stack(
171
+ [a.k_norm.weight.data for a in layers_attn], dim=0
172
+ ).contiguous()
173
+
174
+ def _project_context_kv(
175
+ self,
176
+ context_states: torch.Tensor,
177
+ num_ctx: int,
178
+ num_layers: int,
179
+ num_kv_heads: int,
180
+ head_dim: int,
181
+ ) -> tuple[torch.Tensor, torch.Tensor]:
182
+ normed_context_states = torch.empty(
183
+ (num_layers, num_ctx, context_states.shape[-1]),
184
+ dtype=context_states.dtype,
185
+ device=context_states.device,
186
+ )
187
+ ops.rms_norm(
188
+ normed_context_states,
189
+ context_states.unsqueeze(0).expand(num_layers, -1, -1),
190
+ self._input_layernorm_weights,
191
+ self._rms_norm_eps,
192
+ )
193
+ all_kv_flat = torch.bmm(
194
+ normed_context_states,
195
+ self._kv_weights.transpose(1, 2),
196
+ )
197
+ if self._kv_biases is not None:
198
+ all_kv_flat += self._kv_biases[:, None, :]
199
+ all_kv = (
200
+ all_kv_flat.view(num_layers, num_ctx, 2, num_kv_heads, head_dim)
201
+ .permute(2, 0, 1, 3, 4)
202
+ .contiguous()
203
+ )
204
+ all_k = all_kv[0]
205
+ all_v = all_kv[1]
206
+ return all_k, all_v
207
+
208
+ def _normalize_context_k(self, all_k: torch.Tensor) -> torch.Tensor:
209
+ all_k_normed = torch.empty_like(all_k)
210
+ ops.rms_norm(
211
+ all_k_normed,
212
+ all_k,
213
+ self._k_norm_weights,
214
+ self._rms_norm_eps,
215
+ )
216
+ return all_k_normed
217
+
218
+ def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]) -> set[str]:
219
+ params_dict = dict(self.named_parameters())
220
+ loaded_params: set[str] = set()
221
+ for name, loaded_weight in weights:
222
+ if self.quant_config is not None and (
223
+ scale_name := self.quant_config.get_cache_scale(name)
224
+ ):
225
+ param = params_dict[scale_name]
226
+ weight_loader = getattr(param, "weight_loader", default_weight_loader)
227
+ loaded_weight = (
228
+ loaded_weight if loaded_weight.dim() == 0 else loaded_weight[0]
229
+ )
230
+ weight_loader(param, loaded_weight)
231
+ loaded_params.add(scale_name)
232
+ continue
233
+ if "scale" in name:
234
+ name = maybe_remap_kv_scale_name(name, params_dict)
235
+ if name is None:
236
+ continue
237
+ param = params_dict[name]
238
+ weight_loader = getattr(param, "weight_loader", default_weight_loader)
239
+ weight_loader(param, loaded_weight)
240
+ loaded_params.add(name)
241
+ return loaded_params
242
+
243
+
244
+class DFlashLagunaForCausalLM(nn.Module, SupportsEagle3):
245
+ def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
246
+ nn.Module.__init__(self)
247
+ self.config = vllm_config.speculative_config.draft_model_config.hf_config
248
+ if getattr(self.config, "draft_vocab_size", None) is None:
249
+ raise ValueError("Laguna DFlash config requires `draft_vocab_size`.")
250
+ self.has_own_embed_tokens = False
251
+ self.has_own_lm_head = False
252
+ target_layer_num = vllm_config.model_config.get_num_layers(
253
+ vllm_config.parallel_config
254
+ )
255
+ self.config.target_layer_count = target_layer_num
256
+ target_vocab_size = vllm_config.model_config.get_vocab_size()
257
+ if self.config.draft_vocab_size != target_vocab_size:
258
+ raise ValueError(
259
+ "Laguna DFlash shares the target lm_head and requires "
260
+ "`draft_vocab_size` to match the target vocabulary size "
261
+ f"({self.config.draft_vocab_size} != {target_vocab_size})."
262
+ )
263
+ self.model = DFlashLagunaModel(
264
+ vllm_config=vllm_config,
265
+ prefix="model",
266
+ )
267
+
268
+ self.lm_head = ParallelLMHead(
269
+ self.config.draft_vocab_size,
270
+ self.config.hidden_size,
271
+ prefix=maybe_prefix(prefix, "lm_head"),
272
+ )
273
+ self.logits_processor = LogitsProcessor(self.config.draft_vocab_size)
274
+
275
+ def embed_input_ids(
276
+ self,
277
+ input_ids: torch.Tensor,
278
+ multimodal_embeddings: NestedTensors | None = None,
279
+ is_multimodal: torch.Tensor | None = None,
280
+ ) -> torch.Tensor:
281
+ return self.model.embed_input_ids(input_ids)
282
+
283
+ def forward(
284
+ self,
285
+ input_ids: torch.Tensor,
286
+ positions: torch.Tensor,
287
+ inputs_embeds: torch.Tensor | None = None,
288
+ ) -> torch.Tensor:
289
+ return self.model(input_ids, positions, inputs_embeds)
290
+
291
+ def compute_logits(
292
+ self,
293
+ hidden_states: torch.Tensor,
294
+ ) -> torch.Tensor | None:
295
+ return self.logits_processor(self.lm_head, hidden_states)
296
+
297
+ def precompute_and_store_context_kv(
298
+ self,
299
+ context_states: torch.Tensor,
300
+ context_positions: torch.Tensor,
301
+ context_slot_mapping: torch.Tensor | None = None,
302
+ ) -> None:
303
+ self.model.precompute_and_store_context_kv(
304
+ context_states, context_positions, context_slot_mapping
305
+ )
306
+
307
+ def combine_hidden_states(
308
+ self,
309
+ hidden_states: torch.Tensor,
310
+ ) -> torch.Tensor:
311
+ # Normalize each verifier hidden-state slice, concatenate them, then
312
+ # project into the drafter hidden size used as DFlash context.
313
+ needs_squeeze = hidden_states.dim() == 1
314
+ if needs_squeeze:
315
+ hidden_states = hidden_states.unsqueeze(0)
316
+ num_slices = self.model.num_aux_slices
317
+ slice_size = hidden_states.shape[-1] // num_slices
318
+ slices = hidden_states.view(hidden_states.shape[0], num_slices, slice_size)
319
+ normed = torch.empty_like(slices)
320
+ for i, norm in enumerate(self.model.aux_hidden_norms):
321
+ normed[:, i, :] = norm(slices[:, i, :])
322
+ hidden_states = normed.reshape(hidden_states.shape[0], -1)
323
+ result = self.model.fc(hidden_states)
324
+ result = self.model.hidden_norm(result)
325
+ if needs_squeeze:
326
+ result = result.squeeze(0)
327
+ return result
328
+
329
+ def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]):
330
+ model_weights = {}
331
+ for name, loaded_weight in weights:
332
+ if "lm_head" not in name:
333
+ name = "model." + name
334
+ model_weights[name] = loaded_weight
335
+ process_eagle_weight(self, name)
336
+
337
+ loader = AutoWeightsLoader(self)
338
+ loaded_weight_names = loader.load_weights(model_weights.items())
339
+ loaded_weight_names.add("lm_head.weight")
340
+ loaded_weight_names.add("model.embed_tokens.weight")
341
+ self.model._build_fused_kv_buffers()
342
+ return loaded_weight_names
vllm/model_executor/models/qwen3_dflash.py
+64
-41
@@ -410,18 +410,11 @@ class DFlashQwen3Model(nn.Module):
410
embeds = torch.where(is_mask, self.mask_embedding.to(embeds.dtype), embeds)
411
return embeds
412
413
- def _build_fused_kv_buffers(self) -> None:
414
- """Build fused weight buffers for precompute_and_store_context_kv.
415
-
416
- Must be called after weights are loaded. Stacks the KV-projection
417
- weights, K-norm weights, and RoPE parameters from every attention
418
- layer so that precompute_and_store_context_kv can run one fused
419
- GEMM for all layers at once. Also aliases the weight of the hidden_norm.
420
- """
421
- layers_attn = [layer.self_attn for layer in self.layers]
422
- attn0 = layers_attn[0]
423
- has_bias = attn0.qkv_proj.bias is not None
424
-
413
+ def _build_context_kv_buffers(
414
+ self,
415
+ layers_attn: list[nn.Module],
416
+ has_bias: bool,
417
+ ) -> None:
418
self._hidden_norm_weight = self.hidden_norm.weight.data
419
420
# KV projection weights: [num_layers * 2 * kv_size, hidden_size]
@@ -439,6 +432,20 @@ class DFlashQwen3Model(nn.Module):
432
[a.k_norm.weight.data for a in layers_attn], dim=0
433
).contiguous()
434
435
+ def _build_fused_kv_buffers(self) -> None:
436
+ """Build fused weight buffers for precompute_and_store_context_kv.
437
+
438
+ Must be called after weights are loaded. Stacks the KV-projection
439
+ weights, K-norm weights, and RoPE parameters from every attention
440
+ layer so that precompute_and_store_context_kv can run one fused
441
+ GEMM for all layers at once. Also aliases the weight of the hidden_norm.
442
+ """
443
+ layers_attn = [layer.self_attn for layer in self.layers]
444
+ attn0 = layers_attn[0]
445
+ has_bias = attn0.qkv_proj.bias is not None
446
+
447
+ self._build_context_kv_buffers(layers_attn, has_bias)
448
+
449
# RoPE parameters
450
self._rope_head_size = attn0.rotary_emb.head_size
451
self._rope_cos_sin_cache = attn0.rotary_emb.cos_sin_cache
@@ -468,6 +475,49 @@ class DFlashQwen3Model(nn.Module):
475
# References to inner Attention layers for direct cache writes
476
self._attn_layers = [layer.self_attn.attn for layer in self.layers]
477
478
+ def _project_context_kv(
479
+ self,
480
+ context_states: torch.Tensor,
481
+ num_ctx: int,
482
+ num_layers: int,
483
+ num_kv_heads: int,
484
+ head_dim: int,
485
+ ) -> tuple[torch.Tensor, torch.Tensor]:
486
+ # --- Fused KV projection (one GEMM for all layers) ---
487
+ normed_context_states = torch.empty_like(context_states)
488
+ ops.rms_norm(
489
+ normed_context_states,
490
+ context_states,
491
+ self._hidden_norm_weight,
492
+ self._rms_norm_eps,
493
+ )
494
+ all_kv_flat = F.linear(
495
+ normed_context_states, self._fused_kv_weight, self._fused_kv_bias
496
+ )
497
+ # Single contiguous copy that separates K/V and transposes to
498
+ # layer-major layout. Result: [2, L, num_ctx, nkv, hd] contiguous.
499
+ # Indexing dim-0 gives contiguous [L, num_ctx, nkv, hd] for K and V.
500
+ all_kv = (
501
+ all_kv_flat.view(num_ctx, num_layers, 2, num_kv_heads, head_dim)
502
+ .permute(2, 1, 0, 3, 4)
503
+ .contiguous()
504
+ )
505
+ all_k = all_kv[0] # [L, num_ctx, nkv, hd], contiguous
506
+ all_v = all_kv[1] # [L, num_ctx, nkv, hd], contiguous
507
+ return all_k, all_v
508
+
509
+ def _normalize_context_k(self, all_k: torch.Tensor) -> torch.Tensor:
510
+ # --- Grouped RMSNorm K across all layers ([L, num_ctx, nkv, hd]) ---
511
+ # The weight is selected per layer by the outermost (layer) index.
512
+ all_k_normed = torch.empty_like(all_k)
513
+ ops.rms_norm(
514
+ all_k_normed,
515
+ all_k,
516
+ self._k_norm_weights,
517
+ self._rms_norm_eps,
518
+ )
519
+ return all_k_normed
520
+
521
def precompute_and_store_context_kv(
522
self,
523
context_states: torch.Tensor,
@@ -499,35 +549,8 @@ class DFlashQwen3Model(nn.Module):
549
hd = self._head_dim
550
nkv = self._num_kv_heads
551
502
- # --- Fused KV projection (one GEMM for all layers) ---
503
- normed_context_states = torch.empty_like(context_states)
504
- ops.rms_norm(
505
- normed_context_states,
506
- context_states,
507
- self._hidden_norm_weight,
508
- self._rms_norm_eps,
509
- )
510
- all_kv_flat = F.linear(
511
- normed_context_states, self._fused_kv_weight, self._fused_kv_bias
512
- )
513
- # Single contiguous copy that separates K/V and transposes to
514
- # layer-major layout. Result: [2, L, num_ctx, nkv, hd] contiguous.
515
- # Indexing dim-0 gives contiguous [L, num_ctx, nkv, hd] for K and V.
516
- all_kv = (
517
- all_kv_flat.view(num_ctx, L, 2, nkv, hd).permute(2, 1, 0, 3, 4).contiguous()
518
- )
519
- all_k = all_kv[0] # [L, num_ctx, nkv, hd], contiguous
520
- all_v = all_kv[1] # [L, num_ctx, nkv, hd], contiguous
521
-
522
- # --- Grouped RMSNorm K across all layers ([L, num_ctx, nkv, hd]) ---
523
- # The weight is selected per layer by the outermost (layer) index.
524
- all_k_normed = torch.empty_like(all_k)
525
- ops.rms_norm(
526
- all_k_normed,
527
- all_k,
528
- self._k_norm_weights,
529
- self._rms_norm_eps,
530
- )
552
+ all_k, all_v = self._project_context_kv(context_states, num_ctx, L, nkv, hd)
553
+ all_k_normed = self._normalize_context_k(all_k)
554
555
# --- Fused RoPE across all layers ---
556
# View as [L * num_ctx, kv] so RoPE sees one big batch (no copy).
vllm/model_executor/models/registry.py
+1
@@ -591,6 +591,7 @@ _SPECULATIVE_DECODING_MODELS = {
591
"DFlashDraftModel": ("qwen3_dflash", "DFlashQwen3ForCausalLM"),
592
"DSparkDraftModel": ("vllm.models.deepseek_v4", "DSparkDeepseekV4ForCausalLM"),
593
"Qwen3DSparkModel": ("qwen3_dspark", "Qwen3DSparkForCausalLM"),
594
+ "DFlashLagunaForCausalLM": ("laguna_dflash", "DFlashLagunaForCausalLM"),
595
"PEagleDraftModel": ("llama_eagle3", "Eagle3LlamaForCausalLM"),
596
"PeagleLlamaForCausalLM": ("llama_eagle3", "Eagle3LlamaForCausalLM"),
597
"Eagle3LlamaForCausalLM": ("llama_eagle3", "Eagle3LlamaForCausalLM"),
vllm/v1/spec_decode/llm_base_proposer.py
+2
@@ -28,6 +28,7 @@ from vllm.model_executor.model_loader import get_model
28
from vllm.model_executor.models import supports_multimodal
29
from vllm.model_executor.models.deepseek_eagle3 import Eagle3DeepseekV2ForCausalLM
30
from vllm.model_executor.models.interfaces import SupportsMultiModal
31
+from vllm.model_executor.models.laguna_dflash import DFlashLagunaForCausalLM
32
from vllm.model_executor.models.llama_eagle3 import Eagle3LlamaForCausalLM
33
from vllm.model_executor.models.qwen3_dflash import DFlashQwen3ForCausalLM
34
from vllm.model_executor.models.qwen3_eagle3 import Eagle3Qwen3ForCausalLM
@@ -533,6 +534,7 @@ class SpecDecodeBaseProposer:
534
Eagle3DeepseekV2ForCausalLM,
535
DFlashQwen3ForCausalLM,
536
Eagle3Qwen3ForCausalLM,
537
+ DFlashLagunaForCausalLM,
538
),
539
)
540
target_hidden_states = self.model.combine_hidden_states(