Files
xc-llm-ascend/vllm_ascend/torchair/torchair_attention.py
wangxiyuan a1f142b7ad Drop 0.11.0 support (#4377)
There is a lot hack code for v0.11.0, which makes the code hard to
upgrade to newer vLLM version. Since v0.11.0 will release soon. Let's
drop v0.11.0 support first. Then we'll upgrade to v0.11.2 soon.


- vLLM version: v0.11.0
- vLLM main:
2918c1b49c

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>
2025-11-24 17:08:20 +08:00

458 lines
19 KiB
Python

#
# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
#
# 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.
# This file is a part of the vllm-ascend project.
#
from dataclasses import dataclass
from typing import List, Optional, Tuple, Type
import numpy as np
import torch
import torch.nn as nn
import torch_npu
from vllm.attention.backends.abstract import (AttentionImpl, AttentionLayer,
AttentionType)
from vllm.attention.backends.utils import PAD_SLOT_ID
from vllm.config import VllmConfig
from vllm.utils.math_utils import cdiv
from vllm_ascend.attention.attention_v1 import (AscendAttentionBackend,
AscendAttentionMetadataBuilder,
AscendAttentionState,
AscendMetadata)
from vllm_ascend.attention.utils import AscendCommonAttentionMetadata
from vllm_ascend.torchair.utils import TorchairCommonAttentionMetadata
from vllm_ascend.utils import (ACL_FORMAT_FRACTAL_NZ, aligned_16, is_310p,
nd_to_nz_2d)
class AscendAttentionTorchairBackend(AscendAttentionBackend):
accept_output_buffer: bool = True
@staticmethod
def get_name() -> str:
return "ASCEND_TORCHAIR"
@staticmethod
def get_impl_cls() -> Type["AscendAttentionTorchairBackendImpl"]:
return AscendAttentionTorchairBackendImpl
@staticmethod
def get_builder_cls() -> type["AscendAttentionTorchairMetadataBuilder"]:
return AscendAttentionTorchairMetadataBuilder
@staticmethod
def get_kv_cache_shape(
num_blocks: int,
block_size: int,
num_kv_heads: int,
head_size: int,
) -> Tuple[int, ...]:
return (2, num_blocks, block_size, num_kv_heads * head_size)
@staticmethod
def get_bsh_kv_cache_shape(
num_blocks: int,
block_size: int,
num_kv_heads: int,
head_size: int,
) -> Tuple[int, ...]:
return (2, num_blocks, block_size, num_kv_heads * head_size)
@dataclass
class AscendDecodeMetadata:
# Input positions for rotrary embeddings since for MLA the rotary
# position embeddings are applied inside the attention backend
input_positions: torch.Tensor
block_table: torch.Tensor
seq_lens: torch.Tensor
max_seq_lens: int
seq_lens_list: list[int]
attn_mask: Optional[torch.Tensor] = None
@dataclass
class AscendTorchairMetadata(AscendMetadata):
decode: Optional[AscendDecodeMetadata] = None
class AscendAttentionTorchairMetadataBuilder(AscendAttentionMetadataBuilder):
def __init__(
self,
kv_cache_spec,
layer_names,
vllm_config: VllmConfig,
device: torch.device,
):
super().__init__(kv_cache_spec, layer_names, vllm_config, device)
self.max_num_blocks_per_req = cdiv(
self.model_config.max_model_len,
self.vllm_config.cache_config.block_size)
self.max_blocks = (self.model_config.max_model_len +
self.vllm_config.cache_config.block_size -
1) // self.vllm_config.cache_config.block_size
def _get_graph_runner_block_tables(
self, num_seqs: int, block_tables: torch.Tensor) -> torch.Tensor:
max_blocks = self.max_blocks
graph_block_tables = torch.zeros((num_seqs, max_blocks),
dtype=block_tables.dtype,
device=block_tables.device)
num_blocks = block_tables.size(1)
if num_blocks <= max_blocks:
graph_block_tables[:num_seqs, :
num_blocks] = block_tables[:num_seqs, :
num_blocks]
else:
graph_block_tables[:num_seqs, :
max_blocks] = block_tables[:num_seqs, :
max_blocks]
return graph_block_tables[:, :max_blocks]
def build_torchair_graph_dummy(
self, common_attn_metadata: TorchairCommonAttentionMetadata
) -> AscendTorchairMetadata:
device = self.device
num_reqs = common_attn_metadata.num_reqs
block_table = torch.zeros((num_reqs, self.max_blocks),
dtype=torch.int32,
device=device)
block_table = self._get_graph_runner_block_tables(
num_reqs, block_table)
seq_lens = torch.ones(num_reqs, dtype=torch.int32, device=device)
input_positions = torch.zeros(num_reqs,
dtype=torch.int32,
device=device).long()
slot_mapping = torch.full((num_reqs, ),
PAD_SLOT_ID,
dtype=torch.int32,
device=device)
query_start_loc = torch.full((num_reqs, ),
-1,
dtype=torch.int32,
device=device)
decode_metadata = AscendDecodeMetadata(input_positions=input_positions,
block_table=block_table,
seq_lens=seq_lens,
seq_lens_list=seq_lens.tolist(),
max_seq_lens=1)
attn_metadata = AscendTorchairMetadata(
num_actual_tokens=common_attn_metadata.num_actual_tokens,
block_tables=block_table,
query_lens=0,
query_start_loc=query_start_loc,
seq_lens=seq_lens,
slot_mapping=slot_mapping,
attn_state=AscendAttentionState.DecodeOnly,
decode=decode_metadata)
return attn_metadata
def build(
self,
common_prefix_len: int,
common_attn_metadata: AscendCommonAttentionMetadata,
model: Optional[nn.Module] = None,
):
num_reqs = common_attn_metadata.num_reqs
num_actual_tokens = common_attn_metadata.num_actual_tokens
block_table = common_attn_metadata.block_table_tensor
block_table[:num_reqs, :self.max_num_blocks_per_req] = (
block_table[:num_reqs])
seq_lens = common_attn_metadata.seq_lens_cpu[:num_reqs]
slot_mapping = common_attn_metadata.slot_mapping[:num_actual_tokens]
attn_mask = common_attn_metadata.attn_mask
attn_state = common_attn_metadata.attn_state
if is_310p() and attn_state == AscendAttentionState.PrefillNoCache:
mask_nz = nd_to_nz_2d(attn_mask)
attn_mask = torch_npu.npu_format_cast(mask_nz.contiguous(), 29)
query_start_loc_cpu = common_attn_metadata.query_start_loc_cpu[:
num_reqs
+ 1]
query_start_loc = query_start_loc_cpu.to(self.device,
non_blocking=True)
query_lens = query_start_loc_cpu[1:] - query_start_loc_cpu[:-1]
input_positions = common_attn_metadata.positions[:
num_actual_tokens].long(
)
decode_metadata = None
graph_pad_size = common_attn_metadata.graph_pad_size
use_torchair_graph = graph_pad_size > -1
if common_attn_metadata.attn_state in [
AscendAttentionState.DecodeOnly,
]:
max_seq_lens = seq_lens.max().item()
num_seqs = len(seq_lens)
if use_torchair_graph and common_attn_metadata.attn_state in [
AscendAttentionState.DecodeOnly,
]:
num_reqs_pad_size = 0
num_token_pad_size = 0
if graph_pad_size != 0:
pad_value = 0
num_token_pad_size = graph_pad_size - num_actual_tokens
num_reqs_pad_size = (
graph_pad_size //
common_attn_metadata.decode_token_per_req - num_reqs)
pad_value = 1
padded_seq_lens = seq_lens.tolist() + [pad_value
] * num_reqs_pad_size
seq_lens = torch.from_numpy(
np.array(padded_seq_lens).astype(np.int32))
padding = torch.full((num_token_pad_size, ),
PAD_SLOT_ID,
dtype=slot_mapping.dtype,
device=slot_mapping.device)
slot_mapping = torch.cat([slot_mapping, padding])
block_table_padding = torch.zeros(
(num_reqs_pad_size, ) + block_table.shape[1:],
dtype=block_table.dtype,
device=block_table.device)
block_table = torch.cat([block_table, block_table_padding],
dim=0)
block_table = self._get_graph_runner_block_tables(
num_seqs + num_reqs_pad_size, block_table)
padding_0 = torch.zeros(num_token_pad_size,
dtype=input_positions.dtype,
device=input_positions.device)
input_positions = torch.cat([input_positions, padding_0])
decode_metadata = AscendDecodeMetadata(
input_positions=input_positions,
block_table=block_table,
seq_lens=seq_lens,
seq_lens_list=seq_lens.tolist(),
max_seq_lens=max_seq_lens,
attn_mask=None)
attn_metadata = AscendTorchairMetadata(
decode=decode_metadata,
num_actual_tokens=num_actual_tokens,
block_tables=block_table,
query_start_loc=query_start_loc,
query_lens=query_lens,
seq_lens=seq_lens,
max_query_len=common_attn_metadata.max_query_len,
slot_mapping=slot_mapping,
attn_mask=attn_mask,
attn_state=attn_state)
return attn_metadata
class AscendAttentionTorchairBackendImpl(AttentionImpl):
def __init__(
self,
num_heads: int,
head_size: int,
scale: float,
num_kv_heads: int,
alibi_slopes: Optional[List[float]],
sliding_window: Optional[int],
kv_cache_dtype: str,
logits_soft_cap: Optional[float],
attn_type: str,
kv_sharing_target_layer_name: Optional[str],
**kwargs,
) -> None:
self.num_heads = num_heads
self.head_size = head_size
self.scale = float(scale)
self.num_kv_heads = num_heads if num_kv_heads is None else num_kv_heads
self.hidden_size = self.num_heads * self.head_size
self.kv_cache_dtype = kv_cache_dtype
self.sliding_window = sliding_window
if alibi_slopes is not None:
alibi_slopes = torch.tensor(alibi_slopes,
dtype=torch.float32,
device="npu")
self.alibi_slopes = alibi_slopes
self.attn_type = attn_type
assert self.num_heads % self.num_kv_heads == 0
self.num_queries_per_kv = self.num_heads // self.num_kv_heads
self.key_cache = None
self.value_cache = None
self.scale_tensor = torch.zeros((), device='npu', dtype=torch.int32)
def forward(
self,
layer: AttentionLayer,
query: torch.Tensor,
key: torch.Tensor,
value: torch.Tensor,
kv_cache: torch.Tensor,
attn_metadata: AscendTorchairMetadata,
output: Optional[torch.Tensor] = None,
) -> torch.Tensor:
"""Forward pass with Ascend attention.
Args:
query: shape = [batch_size, seq_len, num_heads * head_size]
key: shape = [batch_size, seq_len, num_kv_heads * head_size]
value: shape = [batch_size, seq_len, num_kv_heads * head_size]
kv_cache: shape = [2, num_blocks, block_size,
num_kv_heads, head_size]
key_cache = [num_blocks, block_size,
num_kv_heads, head_size]
value_cache = [num_blocks, block_size,
num_kv_heads, head_size]
attn_metadata: Metadata for attention.
Returns:
shape = [batch_size * seq_len, num_heads, head_size]
"""
num_tokens = query.shape[0]
use_kv_cache_quant = (kv_cache is not None and len(kv_cache) > 0
and kv_cache[0].numel() > 0
and kv_cache[0].dtype == torch.int8)
if output is None:
output = torch.empty(num_tokens,
self.num_heads,
self.head_size,
dtype=query.dtype,
device=query.device)
if hasattr(layer, 'quant_method') and use_kv_cache_quant:
output = layer.quant_method.apply(layer, query, key, value,
kv_cache, attn_metadata,
self.attn_type, self.scale,
output)
return output.view(num_tokens, self.hidden_size)
if attn_metadata is None:
return output.view(num_tokens, self.hidden_size).fill_(0)
output = output.view(-1, self.num_heads, self.head_size)
assert layer._k_scale_float == 1.0 and layer._v_scale_float == 1.0
attn_type = self.attn_type
if attn_type != AttentionType.DECODER:
raise NotImplementedError("Encoder self-attention and "
"encoder/decoder cross-attention "
"are not implemented for "
"AscendAttentionTorchairBackendImpl")
if kv_cache is not None and kv_cache[0].numel() > 0:
key_cache, value_cache = kv_cache[0], kv_cache[1]
slots = attn_metadata.slot_mapping
block_size = self.scale_tensor + key_cache.shape[1]
slots_indices = slots.reshape(-1, 1)
block_indices = slots_indices // block_size
slots_indices = slots_indices % block_size
indices = torch.cat((block_indices, slots_indices), dim=1)
torch_npu.npu_scatter_nd_update_(key_cache, indices, key)
torch_npu.npu_scatter_nd_update_(value_cache, indices, value)
if attn_metadata.attn_state == AscendAttentionState.PrefillCacheHit:
self.key_cache = key_cache
self.value_cache = value_cache
if attn_metadata.attn_state == AscendAttentionState.PrefillNoCache:
assert attn_metadata is not None
assert attn_metadata.attn_mask is not None
mask = attn_metadata.attn_mask
# View q k v to BSH.
query = query.view(-1, self.num_heads, self.head_size)
key = key.view(-1, self.num_kv_heads, self.head_size)
value = value.view(-1, self.num_kv_heads, self.head_size)
if is_310p():
# align q k v output tensors
query = aligned_16(query)
key = aligned_16(key)
value = aligned_16(value)
output = aligned_16(output)
# do reformat in case of broadcasted tensors
mask = mask.repeat(attn_metadata.seq_lens.size(0), 1, 1, 1)
mask = torch_npu.npu_format_cast(mask.contiguous(),
ACL_FORMAT_FRACTAL_NZ)
torch_npu._npu_flash_attention(query=query,
key=key,
value=value,
mask=mask,
seq_len=attn_metadata.seq_lens,
scale_value=self.scale,
num_heads=self.num_heads,
num_kv_heads=self.num_kv_heads,
out=output)
output = output[:num_tokens, :, :]
elif attn_metadata.attn_state == AscendAttentionState.PrefillCacheHit:
assert attn_metadata is not None
assert attn_metadata.attn_mask is not None
compress_mask = attn_metadata.attn_mask
batch_size = attn_metadata.query_lens.shape[0]
block_table = attn_metadata.block_tables[:batch_size, :]
torch_npu._npu_flash_attention_qlens(
query=query,
key_cache=self.key_cache,
value_cache=self.value_cache,
block_table=block_table,
mask=compress_mask,
seq_len=attn_metadata.query_lens,
context_lens=attn_metadata.seq_lens,
num_kv_heads=self.num_kv_heads,
num_heads=self.num_heads,
scale_value=self.scale,
out=output)
elif attn_metadata.attn_state == AscendAttentionState.DecodeOnly:
decode_meta = attn_metadata.decode
assert decode_meta is not None
seq_lens = decode_meta.seq_lens_list
block_table = decode_meta.block_table
block_size = key_cache.shape[1]
query = query.view(num_tokens, 1,
self.num_heads * self.head_size).contiguous()
output, _ = torch_npu.npu_fused_infer_attention_score(
query=query,
key=key_cache,
value=value_cache,
query_rope=None,
key_rope=None,
num_heads=self.num_heads,
num_key_value_heads=self.num_kv_heads,
input_layout='BSH',
atten_mask=decode_meta.attn_mask,
sparse_mode=0,
scale=self.scale,
antiquant_mode=0,
antiquant_scale=None,
block_table=block_table,
block_size=block_size,
actual_seq_lengths_kv=seq_lens,
)
else:
raise NotImplementedError(
"Torchair graph mode with non-MLA attention backend is still experimental."
"v1 scheduler(chunked prefill) is not supported at this moment. Please"
"setting 'ascend_scheduler_config':{'enabled':true} in additional_config"
"to use ascend scheduler.")
return output.view(num_tokens, self.hidden_size)