Files
xc-llm-ascend/vllm_ascend/xlite/xlite.py
Wang Xiaoran 3ce5a34468 [BugFix] Xlite: Bypass the padding of the graph mode in non-MTP cases to obtain the correct decode num. (#5711)
### What this PR does / why we need it?
This PR fixes a bug in Xlite
backend(https://atomgit.com/openeuler/GVirt/issues/1), The direct cause
of the problem is that the XModel::PrepareAttn function obtained an
illegal number of tokens to be inferred, -540. This illegal value is due
to the padding feature of inference in graph mode and the residual state
across steps. This issue is triggered when a prefill request is newly
added in a step and a decode ends simultaneously. It is first fixed
using num_decode_tokens instead of attn_metadata.num_decodes.
1. In graph mode, vllm_ascend has padding characteristics. In the
_prepare_inputs function, if the number of tokens to be inferred is less
than the set threshold (8 in this case), the attn_metadata.num_decode
array will be expanded to 8.
2. Meanwhile, vllm_ascend uses the class variable self.query_start_loc
of NPUModelRunner to record the tokens to be inferred. Due to poor
coordination with the graph mode padding mechanism when crossing steps,
in some cases (such as when a decode request is completed in a certain
step and a new prefill request is added at the same time), negative
values may be calculated for attn_metadata.query_lens.
3. After type conversion, the negative values in query_lens cause an
overflow. Xlite detects that the number of tokens to be inferred for the
decode request is too large and triggers a "decode len too long" alert.

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

### How was this patch tested?
Same with https://atomgit.com/openeuler/GVirt/issues/1
- vLLM version: v0.13.0
- vLLM main:
2f4e6548ef

Signed-off-by: wwwumr <1127858301@qq.com>
2026-01-09 15:55:30 +08:00

299 lines
12 KiB
Python

#
# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
# Copyright 2023 The vLLM team.
#
# 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 Any, Callable, Tuple
import torch
import torch.nn as nn
from vllm.config import VllmConfig
from vllm.distributed import (get_tensor_model_parallel_world_size,
get_world_group)
from vllm.forward_context import get_forward_context
from vllm.logger import logger
from vllm.sequence import IntermediateTensors
from xlite._C import AttnMHA, Model, ModelAttnMeta, ModelConfig, Runtime
import vllm_ascend.envs as envs_ascend
from vllm_ascend.ascend_config import get_ascend_config
from vllm_ascend.attention.attention_v1 import (AscendAttentionState,
AscendMetadata)
class XliteModel:
def initialize(
self, runnable: nn.Module,
vllm_config: VllmConfig) -> Tuple[Model, int, int, torch.dtype]:
raise NotImplementedError(
"Xlite Model initialize function not implemented.")
class LlamaXliteModel(XliteModel):
def initialize(
self, runnable: nn.Module,
vllm_config: VllmConfig) -> Tuple[Model, int, int, torch.dtype]:
dtype = vllm_config.model_config.dtype
params_dict = dict(runnable.named_parameters())
if hasattr(runnable, "language_model"):
layers = runnable.language_model.model.layers
model_prefix = "language_model."
else:
layers = runnable.model.layers
model_prefix = ""
config = self._build_model_config(vllm_config)
xlite_model = Model()
xlite_model.embed = params_dict.get(model_prefix +
"model.embed_tokens.weight")
xlite_model.norm = params_dict.get(model_prefix + "model.norm.weight")
if vllm_config.model_config.hf_text_config.tie_word_embeddings:
xlite_model.head = xlite_model.embed
else:
xlite_model.head = params_dict.get(model_prefix + "lm_head.weight")
xlite_model.attn_norm = [
layer.input_layernorm.weight for layer in layers
]
xlite_model.attn_out = [
layer.self_attn.o_proj.weight for layer in layers
]
xlite_model.mha_qkv = [
layer.self_attn.qkv_proj.weight for layer in layers
]
xlite_model.mlp_norm = [
layer.post_attention_layernorm.weight for layer in layers
]
xlite_model.mlp_up_gate = [
layer.mlp.gate_up_proj.weight for layer in layers
]
xlite_model.mlp_down = [layer.mlp.down_proj.weight for layer in layers]
mha_qkv_bias = [
layer.self_attn.qkv_proj.bias for layer in layers
if hasattr(layer.self_attn.qkv_proj, "bias")
and layer.self_attn.qkv_proj.bias is not None
]
q_norm = [
layer.self_attn.q_norm.weight for layer in layers
if hasattr(layer.self_attn, "q_norm")
]
k_norm = [
layer.self_attn.k_norm.weight for layer in layers
if hasattr(layer.self_attn, "k_norm")
]
if len(mha_qkv_bias) != config.n_layers:
config.qkv_bias = False
else:
config.qkv_bias = True
xlite_model.mha_qkv_bias = mha_qkv_bias
if (len(q_norm) != config.n_layers or len(k_norm) != config.n_layers):
config.qk_norm = False
else:
config.qk_norm = True
xlite_model.mha_q_norm = q_norm
xlite_model.mha_k_norm = k_norm
rank = torch.distributed.get_rank()
xlite_model.init(config, rank)
freq_cis = self._precompute_freqs_cis(config.head_dim,
config.max_seq_len, dtype,
config.rope_theta)
return (xlite_model, freq_cis, config.hidden_size, dtype)
def _build_model_config(self, vllm_config: VllmConfig) -> ModelConfig:
hf_config = vllm_config.model_config.hf_text_config
if hasattr(hf_config, "text_config"):
hf_config = hf_config.text_config
config = ModelConfig()
config.vocab_size = hf_config.vocab_size
config.hidden_size = hf_config.hidden_size
config.n_layers = hf_config.num_hidden_layers
config.n_heads = hf_config.num_attention_heads
config.n_kv_heads = hf_config.num_key_value_heads
if hasattr(hf_config, "head_dim"):
config.head_dim = hf_config.head_dim
else:
config.head_dim = hf_config.hidden_size // hf_config.num_attention_heads
config.rope_head_dim = config.head_dim
config.norm_eps = hf_config.rms_norm_eps
config.rope_theta = hf_config.rope_theta
config.softmax_scale = config.head_dim**-0.5
config.n_dense_layers = hf_config.num_hidden_layers
config.intermediate_size = hf_config.intermediate_size
config.def_tp_size = get_tensor_model_parallel_world_size()
config.def_dp_size = 1
config.moe_ep_size = 1
config.moe_tp_size = 1
config.attn_type = AttnMHA
config.weight_nz = envs_ascend.VLLM_ASCEND_ENABLE_NZ == 2
scheduler_config = vllm_config.scheduler_config
max_batch_size = scheduler_config.max_num_seqs
max_seq_len = vllm_config.model_config.max_model_len
config.max_m = scheduler_config.max_num_batched_tokens
config.max_batch_size = max_batch_size
config.max_seq_len = max_seq_len
config.block_size = vllm_config.cache_config.block_size
return config
def _precompute_freqs_cis(self,
dim: int,
end: int,
dtype: torch.dtype,
theta: float = 10000.0):
freqs = 1.0 / (theta**(torch.arange(
0, dim, 2, dtype=torch.float32, device='cpu')[:(dim // 2)] / dim))
t = torch.arange(end, device=freqs.device) # type: ignore
freqs = torch.outer(t, freqs).float() # type: ignore
cos_cache = freqs.cos().to(dtype)
sin_cache = freqs.sin().to(dtype)
freq_cis = torch.cat((cos_cache, sin_cache), dim=-1)
return freq_cis.to(device='npu')
def xlite_model_init(
runnable: nn.Module,
vllm_config: VllmConfig) -> Tuple[Model, int, int, torch.dtype]:
strategy_map = {
"LlamaForCausalLM": LlamaXliteModel,
"Qwen2ForCausalLM": LlamaXliteModel,
"Qwen3ForCausalLM": LlamaXliteModel,
"Qwen3VLForConditionalGeneration": LlamaXliteModel,
}
architecture = vllm_config.model_config.architectures[0]
strategy_class = strategy_map.get(architecture)
if not strategy_class:
raise ValueError(f"{architecture} not supported!")
return strategy_class().initialize(runnable, vllm_config)
class XliteWrapper:
"""
xlite graph wrapper
"""
def __init__(self, runnable: nn.Module, vllm_config: VllmConfig):
self.runnable = runnable
self.full_mode = get_ascend_config().xlite_graph_config.full_mode
rank = torch.distributed.get_rank()
local_rank = get_world_group().local_rank
self.xlite_rt = Runtime(local_rank, 0, rank,
get_tensor_model_parallel_world_size())
(self.xlite_model, self.freq_cis, hidden_size,
dtype) = xlite_model_init(runnable, vllm_config)
rt_pool_size = self.xlite_model.get_tensor_pool_size()
if rank == 0:
logger.info(f"xlite runtime pool size: {rt_pool_size} MB")
if self.xlite_rt.init_tensor_pool(rt_pool_size) != 0:
raise ValueError(
f"xlite wrapper init failed! runtime pool size: {rt_pool_size} MB"
)
max_num_tokens = vllm_config.scheduler_config.max_num_batched_tokens
self.hidden_states = torch.empty(max_num_tokens,
hidden_size,
device=f"npu:{local_rank}",
dtype=dtype)
def __getattr__(self, key: str):
# allow accessing the attributes of the runnable.
if hasattr(self.runnable, key):
return getattr(self.runnable, key)
raise AttributeError(f"Attribute {key} not exists in the runnable of "
f"xlite wrapper: {self.runnable}")
def unwrap(self) -> Callable:
# in case we need to access the original runnable.
return self.runnable
def register_kv_caches(self, kv_caches: Any):
self.kv_caches = kv_caches
def __call__(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
intermediate_tensors: IntermediateTensors | None = None,
inputs_embeds: torch.Tensor | None = None,
) -> torch.Tensor | IntermediateTensors | tuple[torch.Tensor,
list[torch.Tensor]]:
forward_context = get_forward_context()
attn_metadata: Any = forward_context.attn_metadata
if attn_metadata is None:
return self.runnable(input_ids, positions, intermediate_tensors,
inputs_embeds)
attn_metadata = next(iter(attn_metadata.values()), None)
if attn_metadata is None or not isinstance(attn_metadata,
AscendMetadata):
return self.runnable(input_ids, positions, intermediate_tensors,
inputs_embeds)
with_prefill = attn_metadata.attn_state not in [
AscendAttentionState.DecodeOnly, AscendAttentionState.SpecDecoding
]
if not with_prefill or self.full_mode:
# TODO: When vllm_ascend enables graph mode, attn_metadata.num_decodes
# will be padded in decode requests. Therefore, it is first fixed using
# num_decode_tokens. However, in the future, when MTP is enabled, there
# may be cases where a single request involves multiple tokens, which
# will need to be solved.
num_decodes = attn_metadata.num_decode_tokens
num_prefills = attn_metadata.num_prefills
batch = num_prefills + num_decodes
seq_lens = attn_metadata.seq_lens[:batch]
seq_tensor = torch.cat([
torch.tensor([0]),
torch.tensor(attn_metadata.actual_seq_lengths_q)
],
dim=0)
query_lens = seq_tensor[1:] - seq_tensor[:-1]
query_lens = query_lens[:batch]
cached_lens = seq_lens - query_lens
xlite_attn_metadata = ModelAttnMeta()
xlite_attn_metadata.lens = query_lens.tolist()
xlite_attn_metadata.cached_lens = cached_lens.tolist()
xlite_attn_metadata.is_prefills = [False] * num_decodes + [
True
] * num_prefills
xlite_attn_metadata.block_tables = attn_metadata.block_tables.cpu(
).tolist()
h = self.hidden_states[:attn_metadata.num_actual_tokens]
stream = torch.npu.current_stream().npu_stream
if inputs_embeds is None:
self.xlite_model.forward(self.xlite_rt, input_ids,
xlite_attn_metadata, self.kv_caches,
self.freq_cis, h, stream)
else:
self.xlite_model.forward_with_inputs_embeds(
self.xlite_rt, inputs_embeds, xlite_attn_metadata,
self.kv_caches, self.freq_cis, h, stream)
return h
else:
return self.runnable(input_ids, positions, intermediate_tensors,
inputs_embeds)