Files
xc-llm-ascend/vllm_ascend/attention/mla_v1.py
Pleaplusone df0ec55162 Disaggregate prefill for kv cache register style (#950)
### What this PR does / why we need it?
This PR adopt `LLMDataDist` for kv cache register and `pull_blocks`
style disaggregate prefill implementation. The interface implementation
mainly follows the design of NIXL PR
https://github.com/vllm-project/vllm/pull/17751/files#diff-7eaad0b7dee0626bf29d10081b0f0c5e3ea15a4af97e7b182a4e0d35f8346953
.

This PR can be test with the following step:
- Generate the rank table for all machine.
- execute`toy_proxy.py` to launch the disaggregate prefill proxy server,
specify the prefill ip, port and the decode ip, port
- Run the prefill server and decode server.
- send the request to the disaggregate prefill proxy

### Does this PR introduce _any_ user-facing change?

### How was this patch tested?


- vLLM version: v0.9.2
- vLLM main:
8d0a01a5f2

---------

Signed-off-by: ganyi <pleaplusone.gy@gmail.com>
Signed-off-by: machenglong <machenglong_yewu@cmss.chinamobile.com>
Signed-off-by: liziyu179 <3475441767@qq.com>
Signed-off-by: underfitc <hucong24@huawei.com>
Signed-off-by: zouyida2052 <zouyida@huawei.com>
Signed-off-by: liziyu <liziyu16@huawei.com>
Signed-off-by: underfituu <hzhucong@163.com>
Co-authored-by: machenglong <machenglong_yewu@cmss.chinamobile.com>
Co-authored-by: liziyu179 <3475441767@qq.com>
Co-authored-by: underfitc <hucong24@huawei.com>
Co-authored-by: zouyida2052 <zouyida@huawei.com>
Co-authored-by: liziyu <liziyu16@huawei.com>
Co-authored-by: underfituu <hzhucong@163.com>
2025-07-26 17:15:47 +08:00

1232 lines
54 KiB
Python

from dataclasses import dataclass
from typing import TYPE_CHECKING, Optional, Tuple, Type, TypeVar
import numpy as np
import torch
import torch_npu
from vllm.attention.backends.abstract import (AttentionBackend, AttentionLayer,
AttentionMetadata,
MLAAttentionImpl)
from vllm.attention.backends.utils import PAD_SLOT_ID
from vllm.config import get_current_vllm_config
from vllm.distributed import get_tensor_model_parallel_world_size
from vllm.model_executor.layers.linear import (LinearBase,
UnquantizedLinearMethod)
from vllm.utils import cdiv, round_down
from vllm_ascend import envs
from vllm_ascend.ascend_config import get_ascend_config
from vllm_ascend.attention.attention_v1 import AscendAttentionState
from vllm_ascend.multistream.base import MSAttentionMetadataSplitConfig
from vllm_ascend.multistream.context import get_multistream_comm_context
from vllm_ascend.multistream.ms_split import model_input_split_v1_mla_attn
from vllm_ascend.ops.attention import vanilla_chunked_prefill_mla
from vllm_ascend.torchair.utils import npu_stream_switch, npu_wait_tensor
from vllm_ascend.utils import npu_prefetch
from vllm_ascend.worker.npu_input_batch import InputBatch
if TYPE_CHECKING:
from vllm.v1.core.sched.output import SchedulerOutput
_ALLOWED_NUM_QUERIES_PER_KV = [32, 64, 128]
class AscendMLABackend(AttentionBackend):
accept_output_buffer: bool = True
@staticmethod
def get_name() -> str:
return "ASCEND_MLA"
@staticmethod
def get_metadata_cls() -> type["AttentionMetadata"]:
return AscendMLAMetadata
@staticmethod
def get_builder_cls():
return AscendMLAMetadataBuilder
@staticmethod
def get_kv_cache_shape(num_blocks: int, block_size: int, num_kv_heads: int,
head_size: int) -> tuple[int, ...]:
return (num_blocks, block_size, num_kv_heads, head_size)
@staticmethod
def get_impl_cls() -> Type["MLAAttentionImpl"]:
return AscendMLAImpl
@dataclass
class AscendMLAPrefillMetadata:
""" Prefill Specific Metadata for Ascend"""
@dataclass
class ChunkedContextMetadata:
# New for MLA (compared to FlashAttention)
# For handling chunked prefill
cu_seq_lens: torch.Tensor
starts: torch.Tensor
seq_tot: list[int]
max_seq_lens: list[int]
workspace: torch.Tensor
chunk_seq_lens: torch.Tensor
attn_mask: torch.Tensor
query_lens: list[int]
seq_lens: list[int]
context_lens: torch.Tensor
input_positions: torch.Tensor
query_start_loc: torch.Tensor
block_table: torch.Tensor
max_query_len: int
max_seq_lens: int
chunked_context: Optional[ChunkedContextMetadata] = None
@dataclass
class AscendMLADecodeMetadata:
# 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 AscendMLAMetadata:
"""Metadata for MLACommon.
NOTE: Please read the comment at the top of the file before trying to
understand this class
"""
# NOTE(sang): Definition of context_len, query_len, and seq_len.
# |---------- N-1 iteration --------|
# |---------------- N iteration ---------------------|
# |- tokenA -|......................|-- newTokens ---|
# |---------- context_len ----------|
# |-------------------- seq_len ---------------------|
# |-- query_len ---|
num_actual_tokens: int # Number of tokens excluding padding.
slot_mapping: torch.Tensor
query_start_loc: torch.Tensor
seq_lens: torch.Tensor
block_tables: torch.Tensor
# New for MLA (compared to FlashAttention)
# For handling prefill decode split
num_decodes: int
num_decode_tokens: int
num_prefills: int
# For logging.
num_input_tokens: int = 0 # Number of tokens including padding.
max_num_tokens_across_dp: int = 0
with_prefill_across_dp: bool = False
query_lens: Optional[list[int]] = None
# The dimension of the attention heads
head_dim: Optional[int] = None
attn_mask: torch.Tensor = None
# chunked prefill by default if no attn_states passed
attn_state: AscendAttentionState = AscendAttentionState.ChunkedPrefill
decode: Optional[AscendMLADecodeMetadata] = None
prefill: Optional[AscendMLAPrefillMetadata] = None
def __post_init__(self):
pass
# supported_head_sizes = AscendMLABackend.get_supported_head_sizes()
# if self.head_dim is not None and self.head_dim \
# not in supported_head_sizes:
# raise ValueError(
# f"Only {supported_head_sizes} are supported for head_dim,",
# f"received {self.head_dim}.")
def split_metadata_for_multistream(
self,
ms_split_config: MSAttentionMetadataSplitConfig,
) -> list["AscendMLAMetadata"]:
"""Split metadata for multi-stream with AscendMLAMetadata"""
return model_input_split_v1_mla_attn(
ms_split_config=ms_split_config,
attn_metadata=self,
_metadata_cls=AscendMLAMetadata,
)
M = TypeVar("M", bound=AscendMLAMetadata)
class AscendMLAMetadataBuilder:
"""
NOTE: Please read the comment at the top of the file before trying to
understand this class
"""
# _attn_mask_builder = None
def __init__(self,
runner,
metadata_cls: Optional[AscendMLAMetadata] = None):
self.metadata_cls: Optional[AscendMLAMetadata] = metadata_cls \
if metadata_cls is not None else AscendMLAMetadata # type: ignore
self.runner = runner
scheduler_config = runner.scheduler_config
model_config = runner.model_config
self.block_size = runner.block_size
self.chunked_prefill_enabled = runner.chunked_prefill_enabled
if self.chunked_prefill_enabled:
self.chunked_prefill_workspace_size = min(
# Max sure there is enough for 8 full length request or at least
# 4 pages of cache per request
max(8 * model_config.max_model_len,
4 * scheduler_config.max_num_seqs * self.block_size),
# For long-context models try not to over-allocate limiting
# kv-cache space, limiting it to 64k tokens,
# which would result in the workspace being:
# 2*(576)*(64*1024) = 144mb
# (assuming 576 MLA head dim, and fp16)
# which would result in up-projected context being
# 2*(192*128)*(64*1024) = 3gb
# (assuming 192 QK head dim, 128 heads, and fp16)
128 * 1024)
assert self.chunked_prefill_workspace_size >= \
scheduler_config.max_num_seqs * self.block_size
self.chunked_prefill_workspace = torch.empty(
(self.chunked_prefill_workspace_size,
model_config.get_head_size()),
dtype=model_config.dtype,
device=runner.device,
)
ascend_config = get_ascend_config()
self.torchair_graph_enabled = ascend_config.torchair_graph_config.enabled
def reorder_batch(self, input_batch: "InputBatch",
scheduler_output: "SchedulerOutput") -> bool:
# We now want to reorder the batch so that the "decode" requests are at
# the front and the "prefill" requests are at the using the least amount
# swaps possible. (NOTE for now we loosely use "decode" to mean requests
# where attention is likely memory-bound and "prefill" to mean requests
# where attention is likely compute-bound, TODO(lucas): figure out a
# better naming here)
decodes = []
prefills = []
num_decode_tokens = 0
num_prefill_tokens = 0
for i, req_id in enumerate(input_batch.req_ids):
num_tokens = scheduler_output.num_scheduled_tokens[req_id]
num_spec_tokens = len(
scheduler_output.scheduled_spec_decode_tokens.get(req_id, []))
# For torch air graph mode we treat spec decoding as decode.
if self.torchair_graph_enabled:
if num_tokens - num_spec_tokens == 1:
decodes.append(i)
num_decode_tokens += num_tokens
else:
prefills.append(i)
num_prefill_tokens += num_tokens
# For eager mode we treat spec decoding as chunked prefill.
else:
if num_tokens == 1:
decodes.append(i)
num_decode_tokens += num_tokens
else:
prefills.append(i)
num_prefill_tokens += num_tokens
# We hope that this is fairly minimal since decodes
# should be around for a number of iterations so hopefully they are
# relatively stationary (and new request are generally appended to the
# persistent batch so already should be at the back)
# To achieve this we loop over the decodes in descending order and
# the prefills in ascending order. We swap decodes from the "back"
# i.e. past where the last decode should be in the reodorered with
# prefills from the front of the batch.
# `decodes` and `prefills` are already in ascending order just based on
# the above loop
num_decodes = len(decodes)
num_prefills = len(prefills)
first_prefill = 0
modified_batch = False
for i in range(1, min(num_decodes, num_prefills) + 1):
# If the decode is at the "back" of the batch, i, we can swap it
# with the prefill closest to the front of the batch
if decodes[num_decodes - i] >= num_decodes:
input_batch.swap_states(prefills[first_prefill],
decodes[num_decodes - i])
first_prefill += 1
modified_batch = True
else:
break
# Save for next `build` call
# TODO(lucas): this is a bit of a hack, we should probably have a
# better way of doing this
self._num_decodes = num_decodes
self._num_prefills = num_prefills
self._num_decode_tokens = num_decode_tokens
self._num_prefill_tokens = num_prefill_tokens
return modified_batch
def _get_graph_runner_block_tables(
self, num_seqs: int, block_tables: torch.Tensor) -> torch.Tensor:
max_batch_size, max_blocks = self.runner.graph_block_tables.shape
assert max_batch_size >= num_seqs
if isinstance(self.runner.graph_block_tables, np.ndarray):
graph_block_tables = torch.zeros((max_batch_size, max_blocks),
dtype=block_tables.dtype,
device=block_tables.device)
else:
graph_block_tables = self.runner.graph_block_tables.to(
device=block_tables.device, dtype=block_tables.dtype)
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[:num_seqs, :max_blocks]
def build_dummy(self, num_reqs: int,
num_actual_tokens: int) -> AscendMLAMetadata:
device = self.runner.device
_, max_blocks = self.runner.graph_block_tables.shape
block_table = torch.zeros((num_reqs, 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 = AscendMLADecodeMetadata(
input_positions=input_positions,
block_table=block_table,
seq_lens=seq_lens,
seq_lens_list=seq_lens.tolist(),
max_seq_lens=1,
attn_mask=self.runner.spec_attn_mask)
return self.metadata_cls( # type: ignore
num_input_tokens=num_actual_tokens,
num_actual_tokens=num_actual_tokens,
slot_mapping=slot_mapping,
head_dim=self.runner.model_config.get_head_size(),
num_decodes=1,
num_decode_tokens=1,
num_prefills=0,
attn_mask=self.runner.attn_mask,
attn_state=AscendAttentionState.DecodeOnly,
prefill=None,
decode=decode_metadata,
query_start_loc=query_start_loc,
seq_lens=seq_lens,
block_tables=block_table,
)
def build(
self,
num_reqs: int,
num_actual_tokens: int,
max_query_len: int,
graph_pad_size: int = -1,
max_num_tokens_across_dp: int = 0,
with_prefill_across_dp: bool = False,
query_start_loc: torch.Tensor = None,
) -> AscendMLAMetadata:
assert self._num_decodes + self._num_prefills == num_reqs
# Note(simon): be careful about the CPU <> GPU memory movement in this
# function. We should avoid GPU -> CPU sync as much as possible because
# it blocks on all previous kernels.
device = self.runner.device
block_table = (self.runner.input_batch.block_table[0].
get_device_tensor()[:num_reqs])
slot_mapping = self.runner.slot_mapping_cpu[:num_actual_tokens].to(
device, non_blocking=True)
input_positions = self.runner.positions_cpu[:num_actual_tokens].to(
device, non_blocking=True).long()
seq_lens_cpu = self.runner.seq_lens_cpu[:num_reqs]
query_lens = seq_lens_cpu - self.runner.input_batch.num_computed_tokens_cpu_tensor[:
num_reqs]
seq_lens = seq_lens_cpu
max_query_len = query_lens.max().item()
max_seq_lens = seq_lens.max().item()
prefill_metadata = None
chunked_context_metadata = None
if self._num_prefills > 0:
reqs_start = self._num_decodes # prefill_start
tokens_start = self._num_decode_tokens
max_query_len = query_lens[tokens_start:].max().item()
max_seq_lens = seq_lens[tokens_start:].max().item()
prefill_query_start_loc = query_start_loc[
reqs_start:] - query_start_loc[reqs_start]
context_lens_cpu = self.runner.input_batch.num_computed_tokens_cpu_tensor[
reqs_start:num_reqs]
max_context_len_cpu = context_lens_cpu.max().item()
num_prefills_with_context_cpu = (context_lens_cpu > 0).sum().item()
if self.chunked_prefill_enabled and max_context_len_cpu > 0:
max_context_chunk = (self.chunked_prefill_workspace_size //
num_prefills_with_context_cpu)
max_context_chunk = round_down(max_context_chunk,
self.block_size)
assert max_context_chunk > 0
num_chunks = cdiv(max_context_len_cpu, max_context_chunk)
chunk_starts = torch.arange(num_chunks, dtype=torch.int32) \
.unsqueeze(1).expand(-1, self._num_prefills) * max_context_chunk
chunk_ends = torch.min(context_lens_cpu.unsqueeze(0),
chunk_starts + max_context_chunk)
chunk_seq_lens = (chunk_ends - chunk_starts).clamp(min=0)
cu_seq_lens_cpu = torch.zeros(num_chunks,
self._num_prefills + 1,
dtype=torch.int32,
pin_memory=True)
torch.cumsum(chunk_seq_lens,
dim=1,
out=cu_seq_lens_cpu[:, 1:],
dtype=torch.int32)
chunked_context_metadata = \
AscendMLAPrefillMetadata.ChunkedContextMetadata(
cu_seq_lens=cu_seq_lens_cpu.to(device, non_blocking=True),
starts=chunk_starts.to(device, non_blocking=True),
seq_tot=chunk_seq_lens.sum(dim=1).tolist(),
max_seq_lens=chunk_seq_lens.max(dim=1).values.tolist(),
chunk_seq_lens=chunk_seq_lens,
workspace=self.chunked_prefill_workspace,
)
prefill_metadata = AscendMLAPrefillMetadata(
attn_mask=self.runner.attn_mask,
query_lens=query_lens[tokens_start:],
seq_lens=seq_lens,
context_lens=seq_lens[tokens_start:],
input_positions=input_positions[tokens_start:],
block_table=block_table[reqs_start:, ...],
max_query_len=max_query_len,
max_seq_lens=max_seq_lens,
query_start_loc=prefill_query_start_loc,
chunked_context=chunked_context_metadata,
)
decode_metadata = None
use_torchair_graph = graph_pad_size != -1
if self._num_decodes > 0:
max_seq_lens = seq_lens[:self._num_decodes].max().item()
seq_lens = seq_lens[:self._num_decode_tokens]
input_positions = input_positions[:self._num_decode_tokens]
block_table = block_table[:self._num_decode_tokens, ...]
if use_torchair_graph and self.runner.attn_state in [
AscendAttentionState.DecodeOnly,
AscendAttentionState.SpecDecoding
]:
num_seqs = len(seq_lens)
if graph_pad_size != 0:
pad_value = 1
padded_seq_lens = seq_lens.tolist() + [pad_value
] * graph_pad_size
else:
padded_seq_lens = seq_lens.tolist()
seq_lens = torch.from_numpy(
np.array(padded_seq_lens).astype(np.int32))
padding = torch.full((graph_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(
(graph_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 + graph_pad_size, block_table)
padding_0 = torch.zeros(graph_pad_size,
dtype=input_positions.dtype,
device=input_positions.device)
input_positions = torch.cat([input_positions, padding_0])
decode_metadata = AscendMLADecodeMetadata(
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=self.runner.spec_attn_mask)
return self.metadata_cls( # type: ignore
num_actual_tokens=num_actual_tokens,
query_lens=query_lens.tolist(),
slot_mapping=slot_mapping,
head_dim=self.runner.model_config.get_head_size(),
num_decodes=self._num_decodes,
num_decode_tokens=self._num_decode_tokens,
num_prefills=self._num_prefills,
attn_mask=self.runner.attn_mask,
attn_state=self.runner.attn_state,
prefill=prefill_metadata,
decode=decode_metadata,
query_start_loc=query_start_loc,
block_tables=block_table,
seq_lens=seq_lens,
max_num_tokens_across_dp=max_num_tokens_across_dp,
with_prefill_across_dp=with_prefill_across_dp,
)
class AscendMLAImpl(MLAAttentionImpl):
"""
NOTE: Please read the comment at the top of the file before trying to
understand this class
"""
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_kv_heads
self.kv_cache_dtype = kv_cache_dtype
# MLA Args
self.q_lora_rank = kwargs['q_lora_rank']
self.kv_lora_rank = kwargs['kv_lora_rank']
self.qk_nope_head_dim = kwargs['qk_nope_head_dim']
self.qk_rope_head_dim = kwargs['qk_rope_head_dim']
self.qk_head_dim = kwargs['qk_head_dim']
self.v_head_dim = kwargs['v_head_dim']
self.rotary_emb = kwargs['rotary_emb']
self.q_proj = kwargs['q_proj']
self.kv_b_proj = kwargs['kv_b_proj']
self.o_proj = kwargs['o_proj']
self.kv_a_proj_with_mqa = kwargs.get('kv_a_proj_with_mqa', None)
self.kv_a_layernorm = kwargs.get('kv_a_layernorm', None)
self.num_queries_per_kv = self.num_heads // self.num_kv_heads
self.tp_size = get_tensor_model_parallel_world_size()
ascend_config = get_ascend_config()
self.torchair_graph_enabled = ascend_config.torchair_graph_config.enabled
self.enable_kv_nz = ascend_config.torchair_graph_config.enable_kv_nz
# Adapt torch air graph mode with spec decoding.
speculative_config = get_current_vllm_config().speculative_config
if speculative_config is not None:
self.spec_token_num = speculative_config.num_speculative_tokens
assert self.spec_token_num > 0
# TODO: support numHeads / numKvHeads < 16 in MLA kernel
if self.torchair_graph_enabled:
assert self.num_queries_per_kv in _ALLOWED_NUM_QUERIES_PER_KV, \
("The allowed number of queries per kv when enabling both MLA and Graph mode"
" only support {32, 64, 128}, Thus this is not supported for DeepSeek-V2-Lite,"
" as it only has 16 attention heads. And if you're using DeepSeek-V3 or DeepSeek-R1,"
" please make sure after the tensor parallel split, num_heads / num_kv_heads in "
"{32, 64, 128}.")
def _v_up_proj_and_o_proj(self, x, enable_multistream_mla: bool = False):
# Convert from (B, N, L) to (N, B, L)
x = x.view(-1, self.num_heads, self.kv_lora_rank).transpose(0, 1)
# Multiply (N, B, L) x (N, L, V) -> (N, B, V)
x = torch.bmm(x, self.W_UV)
# Convert from (N, B, V) to (B, N * V)
x = x.transpose(0, 1).reshape(-1, self.num_heads * self.v_head_dim)
MAX_O_PROJ_PREFETCH_SIZE = 16 * 1024 * 1024 # 16MB
npu_prefetch(self.o_proj.weight,
x,
max_size=MAX_O_PROJ_PREFETCH_SIZE,
enabled=enable_multistream_mla)
return self.o_proj(x, is_prefill=False)[0]
# Return `ql_nope`, `q_pe`
def _q_proj_and_k_up_proj(self, x):
q_nope, q_pe = self.q_proj(x)[0]\
.view(-1, self.num_heads, self.qk_head_dim)\
.split([self.qk_nope_head_dim, self.qk_rope_head_dim], dim=-1)
# Convert from (B, N, P) to (N, B, P)
q_nope = q_nope.transpose(0, 1)
# Multiply (N, B, P) x (N, P, L) -> (N, B, L)
ql_nope = torch.bmm(q_nope, self.W_UK_T)
# Convert from (N, B, L) to (B, N, L)
return ql_nope.transpose(0, 1), q_pe
def process_weights_after_loading(self, act_dtype: torch.dtype):
def get_layer_weight(layer):
WEIGHT_NAMES = ("weight", "qweight", "weight_packed")
for attr in WEIGHT_NAMES:
if hasattr(layer, attr):
return getattr(layer, attr)
raise AttributeError(
f"Layer '{layer}' has no recognized weight attribute:"
f" {WEIGHT_NAMES}.")
def get_and_maybe_dequant_weights(layer: LinearBase):
if not isinstance(layer.quant_method, UnquantizedLinearMethod):
# NOTE: This should only be used offline, since it's O(N^3)
eye = torch.eye(layer.input_size_per_partition,
dtype=act_dtype,
device=get_layer_weight(layer).device)
dequant_weights = layer.quant_method.apply(layer,
eye,
bias=None)
del eye
# standardize to (output, input)
return dequant_weights.T
return layer.weight
# we currently do not have quantized bmm's which are needed for
# `W_UV` and `W_UK_T`, we we just store fp16/bf16 copies and perform
# the bmm's in 16-bit, the extra memory overhead of this is fairly low
kv_b_proj_weight = get_and_maybe_dequant_weights(self.kv_b_proj).T
assert kv_b_proj_weight.shape == (
self.kv_lora_rank,
self.num_heads * (self.qk_nope_head_dim + self.v_head_dim)), (
f"{kv_b_proj_weight.shape=}, "
f"{self.kv_lora_rank=}, "
f"{self.num_heads=}, "
f"{self.qk_nope_head_dim=}, "
f"{self.v_head_dim=}")
kv_b_proj_weight = kv_b_proj_weight.view(
self.kv_lora_rank,
self.num_heads,
self.qk_nope_head_dim + self.v_head_dim,
)
W_UK, W_UV = kv_b_proj_weight.split(
[self.qk_nope_head_dim, self.v_head_dim], dim=-1)
# Convert from (L, N, V) to (N, L, V)
self.W_UV = W_UV.transpose(0, 1).contiguous()
# Convert from (L, N, P) to (N, P, L)
self.W_UK_T = W_UK.permute(1, 2, 0).contiguous()
# Waiting for BMM NZ support
# self.W_UV.data = torch_npu.npu_format_cast(self.W_UV.data, 29)
# self.W_UK_T.data = torch_npu.npu_format_cast(self.W_UK_T.data, 29)
def _compute_prefill_context(
self,
query: torch.Tensor,
kv_c_and_k_pe_cache: Tuple[torch.Tensor],
rope_dim: int,
attn_metadata: AscendMLAMetadata,
prefix_output: torch.Tensor,
prefix_lse: torch.Tensor,
):
assert len(kv_c_and_k_pe_cache) > 1
prefill_metadata = attn_metadata.prefill
if prefill_metadata is None or prefill_metadata.chunked_context is None:
return prefix_output, prefix_lse
iters = len(prefill_metadata.chunked_context.seq_tot)
q_pe = query[..., self.qk_nope_head_dim:]
q_nope = query[..., :self.qk_nope_head_dim]
seq_len1 = torch.tensor(prefill_metadata.query_lens, dtype=torch.int32)
cache_kv_c = kv_c_and_k_pe_cache[0]
cache_k_pe = kv_c_and_k_pe_cache[1]
num_heads = cache_k_pe.size(2)
latent_kv_dim = kv_c_and_k_pe_cache[0].size(-1)
for i in range(iters):
toks = prefill_metadata.chunked_context.seq_tot[i]
seq_len2 = prefill_metadata.chunked_context.chunk_seq_lens[i]
seq_len = torch.stack([seq_len1, seq_len2])
kv_c_normed = torch.empty(toks,
num_heads,
latent_kv_dim,
dtype=query.dtype,
device=query.device)
k_pe = torch.empty(toks,
num_heads,
rope_dim,
dtype=query.dtype,
device=query.device)
torch_npu.atb.npu_paged_cache_load(
cache_kv_c,
cache_k_pe,
prefill_metadata.block_table,
seq_len2.to(query.device),
seq_starts=prefill_metadata.chunked_context.starts[i],
key=kv_c_normed,
value=k_pe,
)
kv_c_normed = kv_c_normed.squeeze()
kv_nope = self.kv_b_proj(kv_c_normed)[0].view( \
-1, self.num_heads, self.qk_nope_head_dim + self.v_head_dim)
k_nope, v = kv_nope\
.split([self.qk_nope_head_dim, self.v_head_dim], dim=-1)
k_pe = k_pe.expand((*k_nope.shape[:-1], -1))
mask = torch.triu(
torch.ones(512, 512, device=query.device, dtype=query.dtype),
1)
torch_npu.atb.npu_ring_mla(
q_nope=q_nope,
q_rope=q_pe,
k_nope=k_nope,
k_rope=k_pe,
value=v,
mask=mask,
seqlen=seq_len,
head_num=self.num_heads,
kv_head_num=self.num_heads,
pre_out=prefix_output,
prev_lse=prefix_lse,
qk_scale=self.scale,
kernel_type="kernel_type_high_precision",
mask_type="no_mask",
input_layout="type_bsnd",
calc_type="calc_type_default",
output=prefix_output,
softmax_lse=prefix_lse)
return prefix_output, prefix_lse
def _forward_prefill(
self,
query: torch.Tensor,
kv_c_normed: torch.Tensor,
k_pe: torch.Tensor,
kv_c_and_k_pe_cache: Tuple[torch.Tensor],
attn_metadata: AscendMLAMetadata,
) -> torch.Tensor:
assert attn_metadata.prefill is not None
assert len(kv_c_and_k_pe_cache) > 1
num_tokens = query.size(0)
attn_output = torch.empty(num_tokens,
self.num_heads,
self.v_head_dim,
dtype=query.dtype,
device=query.device)
k_nope, value = self.kv_b_proj(kv_c_normed)[0].view(
-1, self.num_heads, self.qk_nope_head_dim + self.v_head_dim).split(
[self.qk_nope_head_dim, self.v_head_dim], dim=-1)
k_pe = k_pe.expand((*k_nope.shape[:-1], -1))
# Here is only 2 possibility of input, ChunkedPrefill or PrefillNoCache
ascend_config = get_ascend_config()
if attn_metadata.attn_state in [
AscendAttentionState.ChunkedPrefill,
AscendAttentionState.SpecDecoding,
AscendAttentionState.PrefillCacheHit
] and not ascend_config.chunked_prefill_for_mla:
attn_output_torch = torch.empty(num_tokens,
self.num_heads * self.v_head_dim,
dtype=query.dtype,
device=query.device)
# current requests is chunked in prefill, disable flash attention with chunked prefill
vanilla_chunked_prefill_mla(
output=attn_output_torch,
query=query,
kv_cache=kv_c_and_k_pe_cache,
block_tables=attn_metadata.prefill.block_table,
query_lens=attn_metadata.prefill.query_lens,
context_lens=attn_metadata.prefill.context_lens,
kv_b_proj=self.kv_b_proj,
max_query_len=attn_metadata.prefill.max_query_len,
max_context_len=attn_metadata.prefill.max_seq_lens,
nope_dim=self.qk_nope_head_dim,
rope_dim=self.qk_rope_head_dim,
v_head_dim=self.v_head_dim,
scale=self.scale,
alibi_slopes=None,
causal=True)
elif attn_metadata.attn_state in [
AscendAttentionState.ChunkedPrefill,
AscendAttentionState.SpecDecoding,
AscendAttentionState.PrefillCacheHit
]:
attn_lse = torch.empty(self.num_heads,
num_tokens,
dtype=torch.float32,
device=query.device)
q_pe = query[..., self.qk_nope_head_dim:]
q_nope = query[..., :self.qk_nope_head_dim]
mask = torch.triu(
torch.ones(512, 512, device=query.device, dtype=query.dtype),
1) # 512: mask only support 512
if attn_metadata.num_prefills > 1:
mask = mask.unsqueeze(0).repeat(attn_metadata.num_prefills, 1,
1)
torch_npu.atb.npu_ring_mla(
q_nope=q_nope,
q_rope=q_pe,
k_nope=k_nope,
k_rope=k_pe,
value=value,
mask=mask,
seqlen=torch.tensor(attn_metadata.prefill.query_lens,
dtype=torch.int32),
head_num=self.num_heads,
kv_head_num=self.num_heads,
pre_out=None,
prev_lse=None,
qk_scale=self.scale,
kernel_type="kernel_type_high_precision",
mask_type="mask_type_triu",
input_layout="type_bsnd",
calc_type="calc_type_first_ring",
output=attn_output,
softmax_lse=attn_lse)
attn_output, attn_lse = self._compute_prefill_context( \
query, kv_c_and_k_pe_cache, self.qk_rope_head_dim, attn_metadata, attn_output, attn_lse)
elif attn_metadata.attn_state == AscendAttentionState.PrefillNoCache:
key = torch.cat((k_nope, k_pe), dim=-1)
torch_npu._npu_flash_attention(
query=query,
key=key,
value=value,
mask=attn_metadata.attn_mask,
seq_len=attn_metadata.prefill.context_lens,
scale_value=self.scale,
num_heads=self.num_heads,
num_kv_heads=self.num_heads,
out=attn_output)
attn_output = attn_output.view(-1, self.num_heads, self.v_head_dim)
else:
raise RuntimeError(
"Unexpected path reached, AscendMLAImpl should only have PrefillNoCache, PrefillCacheHit, ChunkedPrefill and SpecDecoding scenario in forward prefill, please file a bug to vllm-ascend !"
)
attn_output = attn_output.reshape(
[num_tokens, self.num_heads * self.v_head_dim])
if attn_metadata.attn_state in [
AscendAttentionState.ChunkedPrefill,
AscendAttentionState.SpecDecoding,
AscendAttentionState.PrefillCacheHit
] and not ascend_config.chunked_prefill_for_mla:
attn_output = attn_output_torch
current_ms_metadata = get_multistream_comm_context()
if current_ms_metadata is None:
return self.o_proj(attn_output, is_prefill=True)[0]
else:
current_ms_metadata.before_comm_event.record()
with torch.npu.stream(current_ms_metadata.comm_stream):
current_ms_metadata.before_comm_event.wait()
return self.o_proj(attn_output, is_prefill=True)[0]
def exec_kv(
self,
hidden_states: torch.Tensor,
cos: torch.Tensor,
sin: torch.Tensor,
kv_cache: Tuple,
slots: torch.Tensor,
):
B = hidden_states.shape[0]
N = self.num_kv_heads
S = 1
kv = self.kv_a_proj_with_mqa(hidden_states)[0]
# npu_kv_rmsnorm_rope_cache needs [B, N, S, D]
kv = kv.view(B, N, S, self.kv_lora_rank + self.qk_rope_head_dim)
cache_mode = "PA_NZ" if self.enable_kv_nz else "PA"
k_pe, k_nope, _, _ = torch_npu.npu_kv_rmsnorm_rope_cache(
kv,
self.kv_a_layernorm.weight,
cos,
sin,
slots.to(torch.int64),
kv_cache[1],
kv_cache[0],
epsilon=self.kv_a_layernorm.variance_epsilon,
cache_mode=cache_mode,
)
return k_pe, k_nope, kv
def exec_kv_prefill(
self,
hidden_states: torch.Tensor,
cos: torch.Tensor,
sin: torch.Tensor,
kv_cache: Tuple,
slots: torch.Tensor,
):
B = hidden_states.shape[0]
N = self.num_kv_heads
S = 1
kv = self.kv_a_proj_with_mqa(hidden_states)[0]
# npu_kv_rmsnorm_rope_cache needs [B, N, S, D]
kv = kv.view(B, N, S, self.kv_lora_rank + self.qk_rope_head_dim)
cache_mode = "PA_BLK_NZ" if self.enable_kv_nz else "PA"
_, _, k_pe, k_nope = torch_npu.npu_kv_rmsnorm_rope_cache(
kv,
self.kv_a_layernorm.weight,
cos,
sin,
slots.to(torch.int64),
kv_cache[1],
kv_cache[0],
epsilon=self.kv_a_layernorm.variance_epsilon,
cache_mode=cache_mode,
is_output_kv=True,
)
return k_pe, k_nope
def rope_single(
self,
x: torch.Tensor,
cos: torch.Tensor,
sin: torch.Tensor,
) -> torch.Tensor:
B, N, D = x.shape
S = 1
x = x.view(B, N, S, D)
x = torch_npu.npu_interleave_rope(x, cos, sin)
return x.view(B, N, D)
def _forward_decode(
self,
q_nope: torch.Tensor,
q_pe: torch.Tensor,
k_nope: torch.Tensor,
k_pe: torch.Tensor,
kv_c_and_k_pe_cache: Tuple[torch.Tensor],
attn_metadata: AscendMLAMetadata,
enable_multistream_mla: bool = False,
) -> torch.Tensor:
decode_meta = attn_metadata.decode
assert decode_meta is not None
num_tokens = q_nope.size(0)
if self.running_in_graph:
# TorchAir's shape is [bs, num_heads_per_rank, q_seq_len, dim]
if attn_metadata.attn_state == AscendAttentionState.SpecDecoding:
assert num_tokens % self.spec_token_num == 0
q_nope = q_nope.view(num_tokens // (self.spec_token_num + 1),
self.spec_token_num + 1, self.num_heads,
-1)
q_pe = q_pe.view(num_tokens // (self.spec_token_num + 1),
self.spec_token_num + 1, self.num_heads, -1)
if not self.enable_kv_nz:
q_nope = q_nope.transpose(1, 2).contiguous()
q_pe = q_pe.transpose(1, 2).contiguous()
sparse_mode = 3
spec_attn_mask = attn_metadata.decode.attn_mask # type:ignore
else:
if self.enable_kv_nz:
q_nope = q_nope.view(num_tokens, 1, self.num_heads, -1)
q_pe = q_pe.view(num_tokens, 1, self.num_heads, -1)
else:
q_nope = q_nope.view(num_tokens, self.num_heads, 1, -1)
q_pe = q_pe.view(num_tokens, self.num_heads, 1, -1)
sparse_mode = 0
spec_attn_mask = None
# shape of knope/k_pe for npu graph mode should be:
# [num_blocks, num_kv_heads, block_size, self.kv_lora_rank/self.qk_rope_head_dim]
block_size = kv_c_and_k_pe_cache[0].shape[1]
if self.enable_kv_nz:
k_nope = k_nope.view(-1, self.num_kv_heads,
self.kv_lora_rank // 16, block_size, 16)
k_pe = k_pe.view(-1, self.num_kv_heads,
self.qk_rope_head_dim // 16, block_size, 16)
input_layout = "BSND"
else:
k_nope = k_nope.view(-1, self.num_kv_heads, block_size,
self.kv_lora_rank)
k_pe = k_pe.view(-1, self.num_kv_heads, block_size,
self.qk_rope_head_dim)
input_layout = "BNSD"
attn_output, _ = torch_npu.npu_fused_infer_attention_score(
q_nope,
k_nope,
k_nope,
query_rope=q_pe,
key_rope=k_pe,
num_heads=self.num_heads,
num_key_value_heads=self.num_kv_heads,
input_layout=input_layout,
atten_mask=spec_attn_mask,
sparse_mode=sparse_mode,
scale=self.scale,
antiquant_mode=0,
antiquant_scale=None,
block_table=decode_meta.block_table,
block_size=block_size,
actual_seq_lengths_kv=decode_meta.seq_lens_list,
)
else:
# The MLA_PA path will be used as default path in the future, `_npu_paged_attention_mla` will
# be removed after the torch_npu contains `torch_npu.atb.npu_multi_head_latent_attention` become
# public available
assert len(kv_c_and_k_pe_cache) > 1
if envs.VLLM_ASCEND_MLA_PA:
attn_output = torch_npu.atb.npu_multi_head_latent_attention(
q_nope, q_pe, kv_c_and_k_pe_cache[0],
kv_c_and_k_pe_cache[1], attn_metadata.decode.block_table,
attn_metadata.decode.seq_lens, self.num_heads, self.scale,
self.num_kv_heads)
else:
q = torch.cat([q_nope, q_pe], dim=-1)
attn_output = torch.empty(
[num_tokens, self.num_heads, self.kv_lora_rank],
dtype=q.dtype,
device=q.device)
k_cache = torch.cat(
[kv_c_and_k_pe_cache[0], kv_c_and_k_pe_cache[1]], dim=-1)
torch_npu._npu_paged_attention_mla(
query=q,
key_cache=k_cache,
num_kv_heads=self.num_kv_heads,
num_heads=self.num_heads,
scale_value=self.scale,
block_table=attn_metadata.decode.
block_table, # type:ignore
context_lens=attn_metadata.decode.seq_lens, # type:ignore
mla_vheadsize=self.kv_lora_rank,
out=attn_output)
current_ms_metadata = get_multistream_comm_context()
if current_ms_metadata is None:
return self._v_up_proj_and_o_proj(attn_output,
enable_multistream_mla)
else:
current_ms_metadata.before_comm_event.record()
with torch.npu.stream(current_ms_metadata.comm_stream):
current_ms_metadata.before_comm_event.wait()
return self._v_up_proj_and_o_proj(attn_output)
def forward(
self,
layer: AttentionLayer,
hidden_states_or_q_c: torch.Tensor, # query in unified attn
hidden_states_or_kv_c_normed: torch.Tensor, # key in unified attn
k_pe: torch.Tensor, # value in unified attn
kv_cache: Tuple[torch.Tensor],
attn_metadata: M,
output: Optional[torch.Tensor] = None,
enable_multistream_mla: bool = False,
ckq: Optional[torch.Tensor] = None,
) -> torch.Tensor:
assert output is not None, "Output tensor must be provided."
if attn_metadata is None:
# Profiling run.
return output
self.running_in_graph = self.torchair_graph_enabled and attn_metadata.attn_state in [
AscendAttentionState.DecodeOnly, AscendAttentionState.SpecDecoding
]
num_actual_toks = attn_metadata.num_actual_tokens
if k_pe is None and not self.running_in_graph:
if not self.torchair_graph_enabled:
kv_c, k_pe = self.kv_a_proj_with_mqa(
hidden_states_or_kv_c_normed)[0].split(
[self.kv_lora_rank, self.qk_rope_head_dim], dim=-1)
kv_c_normed = self.kv_a_layernorm(kv_c.contiguous())
else:
kv_c_normed = hidden_states_or_kv_c_normed
assert attn_metadata.num_decodes is not None and \
attn_metadata.num_prefills is not None and \
attn_metadata.num_decode_tokens is not None
has_decode = attn_metadata.num_decodes > 0
has_prefill = attn_metadata.num_prefills > 0
num_decode_tokens = attn_metadata.num_decode_tokens
if not self.running_in_graph:
# Inputs and outputs may be padded for CUDA graphs
output_padded = output
output = output[:num_actual_toks, ...]
if not self.torchair_graph_enabled:
kv_c_normed = kv_c_normed[:num_actual_toks, ...]
prefill_k_c_normed = kv_c_normed[num_decode_tokens:]
if not self.running_in_graph:
hidden_states_or_q_c = hidden_states_or_q_c[:num_actual_toks, ...]
prefill_hs_or_q_c = hidden_states_or_q_c[num_decode_tokens:]
if not self.torchair_graph_enabled:
decode_hs_or_q_c = hidden_states_or_q_c[:num_decode_tokens]
k_pe = k_pe[:num_actual_toks, ...]
k_pe = k_pe.unsqueeze(1)
decode_k_pe = k_pe[:num_decode_tokens]
prefill_k_pe = k_pe[num_decode_tokens:]
else:
decode_hs_or_q_c = hidden_states_or_q_c
if has_decode:
decode_k_nope = None
assert attn_metadata.decode is not None
if self.running_in_graph:
seq_len = self.rotary_emb.max_position_embeddings * self.rotary_emb.scaling_factor
cos = self.rotary_emb.cos_cached[:seq_len].to(
dtype=decode_hs_or_q_c.dtype)
sin = self.rotary_emb.sin_cached[:seq_len].to(
dtype=decode_hs_or_q_c.dtype)
cos = cos[attn_metadata.decode.input_positions]
sin = sin[attn_metadata.decode.input_positions]
cos = cos[:, None, None, :]
sin = sin[:, None, None, :]
with npu_stream_switch("mla_secondary",
0,
enabled=enable_multistream_mla):
npu_wait_tensor(hidden_states_or_kv_c_normed,
ckq,
enabled=enable_multistream_mla)
decode_k_pe, decode_k_nope, decode_kv = self.exec_kv(
hidden_states_or_kv_c_normed, cos, sin, kv_cache,
attn_metadata.slot_mapping)
# Without explicitly controlling the order, IndexByTensor operations
# would be placed after `matmul W_KV_T` hindering the overlapping of
# KvRmsNormRopeCache and SingleRope.
npu_wait_tensor(decode_hs_or_q_c,
cos,
enabled=enable_multistream_mla)
npu_wait_tensor(decode_hs_or_q_c,
sin,
enabled=enable_multistream_mla)
npu_wait_tensor(decode_hs_or_q_c,
decode_kv,
enabled=enable_multistream_mla)
decode_ql_nope, decode_q_pe = \
self._q_proj_and_k_up_proj(decode_hs_or_q_c)
if self.running_in_graph:
with npu_stream_switch("mla_secondary",
0,
enabled=enable_multistream_mla):
npu_wait_tensor(decode_q_pe,
decode_k_pe,
enabled=enable_multistream_mla)
decode_q_pe = self.rope_single(decode_q_pe, cos, sin)
else:
decode_q_pe[...], decode_k_pe[...] = self.rotary_emb(
attn_metadata.decode.input_positions,
decode_q_pe.contiguous(),
decode_k_pe,
max_seq_len=attn_metadata.decode.max_seq_lens)
if has_prefill:
assert attn_metadata.prefill is not None
prefill_q = self.q_proj(prefill_hs_or_q_c)[0]\
.view(-1, self.num_heads, self.qk_head_dim)
prefill_q_pe = prefill_q[..., self.qk_nope_head_dim:]
prefill_q_nope = prefill_q[..., :self.qk_nope_head_dim]
if self.torchair_graph_enabled:
num_tokens = prefill_hs_or_q_c.shape[0]
seq_len = self.rotary_emb.max_position_embeddings * self.rotary_emb.scaling_factor
cos = self.rotary_emb.cos_cached[:seq_len].to(
dtype=prefill_q_pe.dtype)
sin = self.rotary_emb.sin_cached[:seq_len].to(
dtype=prefill_q_pe.dtype)
cos = cos[attn_metadata.prefill.input_positions]
sin = sin[attn_metadata.prefill.input_positions]
cos = cos[:, None, None, :]
sin = sin[:, None, None, :]
prefill_q_pe = self.rope_single(prefill_q_pe, cos, sin)
prefill_k_pe, prefill_k_nope = self.exec_kv_prefill(
hidden_states_or_kv_c_normed, cos, sin, kv_cache,
attn_metadata.slot_mapping)
kv_c_normed = prefill_k_nope[:num_actual_toks, ...]
prefill_k_c_normed = prefill_k_nope[num_decode_tokens:]
prefill_k_pe = prefill_k_pe.view(num_tokens, self.num_kv_heads,
-1)
prefill_q = torch.cat([prefill_q_nope, prefill_q_pe], dim=-1)
else:
prefill_q_pe[...], prefill_k_pe[...] = self.rotary_emb(
attn_metadata.prefill.input_positions,
prefill_q_pe.contiguous(),
prefill_k_pe,
max_seq_len=attn_metadata.prefill.max_seq_lens)
assert len(
kv_cache
) > 1, "the number of kv cache should be greater than 1, namely (nope_cache and rope_cache)"
if self.torchair_graph_enabled:
if kv_cache[0].numel(
) > 0 and attn_metadata.attn_state == AscendAttentionState.PrefillNoCache:
slots = attn_metadata.slot_mapping
# NOTE: Separate the kv cache in advance to avoid OOM or other issues
torch_npu._npu_reshape_and_cache(key=kv_c_normed.view(
num_tokens, self.num_kv_heads, -1),
value=prefill_k_pe,
key_cache=kv_cache[0],
value_cache=kv_cache[1],
slot_indices=slots)
else:
kv_c_normed = kv_c_normed.view(
[num_actual_toks, self.num_kv_heads, -1])
torch_npu._npu_reshape_and_cache(
key=kv_c_normed,
value=k_pe,
key_cache=kv_cache[0],
value_cache=kv_cache[1],
slot_indices=attn_metadata.slot_mapping)
if has_prefill:
# FIX: aicore move should be also placed on the comm stream in dbo,
# otherwise it may affect the accuracy
# TODO: use an elegant way to overlap
output_prefill = self._forward_prefill(prefill_q,
prefill_k_c_normed,
prefill_k_pe, kv_cache,
attn_metadata)
current_ms_metadata = get_multistream_comm_context()
if current_ms_metadata is not None:
with torch.npu.stream(current_ms_metadata.comm_stream):
output[num_decode_tokens:] = output_prefill
current_ms_metadata.after_comm_event.record()
else:
output[num_decode_tokens:] = output_prefill
if has_decode:
if self.running_in_graph:
return self._forward_decode(decode_ql_nope, decode_q_pe,
decode_k_nope, decode_k_pe,
kv_cache, attn_metadata,
enable_multistream_mla)
else:
output_decode = self._forward_decode(decode_ql_nope,
decode_q_pe,
decode_k_nope,
decode_k_pe, kv_cache,
attn_metadata)
current_ms_metadata = get_multistream_comm_context()
if current_ms_metadata is not None:
with torch.npu.stream(current_ms_metadata.comm_stream):
output[:num_decode_tokens] = output_decode
current_ms_metadata.after_comm_event.record()
else:
output[:num_decode_tokens] = output_decode
return output_padded