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sglang/python/sglang/srt/layers/attention/aiter_backend.py
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43 KiB
Python

from __future__ import annotations
"""
end to end attention solution with aiter kernels
"""
import math
import os
from dataclasses import dataclass
from enum import Enum, auto
from functools import partial
from typing import TYPE_CHECKING, List, Optional, Union
import torch
import triton
import triton.language as tl
from sglang.global_config import global_config
from sglang.srt.layers.attention.base_attn_backend import AttentionBackend
from sglang.srt.layers.attention.utils import create_flashinfer_kv_indices_triton
from sglang.srt.layers.dp_attention import (
get_attention_tp_size,
is_dp_attention_enabled,
)
from sglang.srt.model_executor.forward_batch_info import ForwardBatch, ForwardMode
if TYPE_CHECKING:
from sglang.srt.layers.radix_attention import RadixAttention
from sglang.srt.model_executor.model_runner import ModelRunner
from sglang.srt.speculative.spec_info import SpecInfo
try:
from aiter import (
flash_attn_varlen_func,
mha_batch_prefill_func,
paged_attention_ragged,
)
from aiter.mla import mla_decode_fwd, mla_prefill_fwd
except ImportError:
print(
"aiter is AMD specific kernel library. Please make sure aiter is installed on your AMD device."
)
from sglang.srt.configs.model_config import AttentionArch
class WrapperDispatch(Enum):
SLIDING_WINDOW = auto()
CROSS_ATTENTION = auto()
@dataclass
class ForwardMetadata:
kv_indptr: torch.Tensor
kv_indices: torch.Tensor
qo_indptr: torch.Tensor
kv_last_page_len: torch.Tensor
max_q_len: int
max_kv_len: Optional[int]
global_workspace_buffer = None
_AITER_PARTITION_SIZE_ROCM = 256
class AiterAttnBackend(AttentionBackend):
def __init__(
self,
model_runner: ModelRunner,
skip_prefill: bool = False,
kv_indptr_buf: Optional[torch.Tensor] = None,
):
super().__init__()
# Lazy import to avoid the initialization of cuda context
from sglang.srt.layers.attention.triton_ops.extend_attention import (
extend_attention_fwd,
)
self.extend_attention_fwd = torch.compiler.disable(extend_attention_fwd)
self.device = model_runner.device
self.is_multimodal = model_runner.model_config.is_multimodal
self.num_draft_tokens = model_runner.server_args.speculative_num_draft_tokens
self.speculative_num_steps = model_runner.server_args.speculative_num_steps
self.num_head = (
model_runner.model_config.num_attention_heads // get_attention_tp_size()
)
self.head_dim = model_runner.model_config.head_dim
self.v_head_dim = model_runner.token_to_kv_pool.get_value_buffer(0).shape[-1]
self.num_kv_head = model_runner.model_config.get_num_kv_heads(
get_attention_tp_size()
)
self.kv_cache_dtype = model_runner.kv_cache_dtype
self.req_to_token = model_runner.req_to_token_pool.req_to_token
self.use_mla = model_runner.model_config.attention_arch == AttentionArch.MLA
# Parse constants
self.max_context_len = model_runner.model_config.context_len
self.skip_prefill = skip_prefill
max_bs = model_runner.req_to_token_pool.size
if kv_indptr_buf is None:
self.kv_indptr = torch.zeros(
(max_bs + 1,), dtype=torch.int32, device=model_runner.device
)
else:
self.kv_indptr = kv_indptr_buf
self.kv_last_page_len = torch.ones(
(max_bs,), dtype=torch.int32, device=model_runner.device
)
self.qo_indptr = torch.zeros(
(max_bs + 1,), dtype=torch.int32, device=model_runner.device
)
# Create prefill indices updater
if not skip_prefill:
self.indices_updater_prefill = AiterIndicesUpdaterPrefill(
model_runner, self
)
if self.use_mla:
self.mla_indices_updater_prefill = AiterMlaIndicesUpdaterPrefill(
model_runner, self
)
# aiter kernel related initialization
self.max_num_partitions = (
self.max_context_len + _AITER_PARTITION_SIZE_ROCM - 1
) // _AITER_PARTITION_SIZE_ROCM
nbyes_per_qo_elem = torch.finfo(torch.float32).bits // 8
if not self.use_mla:
self.workspace_buffer = torch.empty(
(max_bs * self.num_head * self.max_num_partitions * self.head_dim)
* nbyes_per_qo_elem
+ 2 * (max_bs * self.num_head * self.max_num_partitions) * 4,
dtype=torch.uint8,
device=self.device,
)
self.scale = float(1.0 / (self.head_dim**0.5))
self.k_scale = self.v_scale = torch.tensor([1.0], dtype=torch.float32).to(
self.device
)
self.logits_soft_cap = 0.0
self.forward_metadata: ForwardMetadata = None
if self.use_mla:
self.qo_indptr_ = torch.zeros(
(max_bs + 1,), dtype=torch.int32, device=model_runner.device
)
self.enable_dp_attention = is_dp_attention_enabled()
def init_forward_metadata(self, forward_batch: ForwardBatch):
"""Init auxiliary variables for triton attention backend."""
bs = forward_batch.batch_size
kv_indptr = self.kv_indptr
spec_info = forward_batch.spec_info
qo_indptr = None
kv_last_page_len = None
max_q_len = None
if forward_batch.forward_mode.is_decode_or_idle():
if spec_info is None:
kv_indptr[1 : bs + 1] = torch.cumsum(forward_batch.seq_lens, dim=0)
kv_indptr = kv_indptr[: bs + 1]
kv_indices = torch.empty(
forward_batch.seq_lens_sum, dtype=torch.int32, device=self.device
)
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
forward_batch.req_pool_indices,
forward_batch.seq_lens,
kv_indptr,
None,
kv_indices,
self.req_to_token.stride(0),
)
else:
kv_indptr, kv_indices = spec_info.kv_indptr, spec_info.kv_indices
bs = kv_indptr.shape[0] - 1
if self.use_mla:
qo_indptr = self.qo_indptr_[: bs + 1]
qo_indptr[1 : bs + 1] = torch.cumsum(self.kv_last_page_len[:bs], dim=0)
kv_last_page_len = self.kv_last_page_len[:bs]
max_q_len = 1
self.forward_metadata = ForwardMetadata(
kv_indptr,
kv_indices,
qo_indptr,
kv_last_page_len,
max_q_len,
None,
)
elif forward_batch.forward_mode.is_draft_extend():
if self.use_mla:
kv_indices, kv_indptr, qo_indptr, custom_mask = (
spec_info.generate_attn_arg_prefill(
forward_batch.req_pool_indices,
forward_batch.seq_lens,
forward_batch.seq_lens_sum,
self.req_to_token,
)
)
self.forward_metadata = ForwardMetadata(
kv_indptr,
kv_indices,
qo_indptr,
# self.mla_indices_updater_prefill.kv_last_page_len,
self.kv_last_page_len[:bs],
max(forward_batch.extend_seq_lens_cpu),
forward_batch.seq_lens_cpu.max().item(),
)
else:
self.indices_updater_prefill.update(
forward_batch.req_pool_indices,
forward_batch.seq_lens,
forward_batch.seq_lens_sum,
prefix_lens=None,
encoder_lens=forward_batch.encoder_lens,
spec_info=forward_batch.spec_info,
)
self.forward_metadata = ForwardMetadata(
self.indices_updater_prefill.kv_indptr,
self.indices_updater_prefill.kv_indices,
None,
None,
self.indices_updater_prefill.max_q_len,
self.indices_updater_prefill.max_kv_len,
)
elif forward_batch.forward_mode.is_target_verify():
if self.use_mla:
draft_num = spec_info.draft_token_num
kv_lens = forward_batch.seq_lens + draft_num
kv_lens_sum = forward_batch.seq_lens_sum + draft_num * bs
device = forward_batch.seq_lens.device
qo_indptr = torch.arange(
0,
(1 + bs) * draft_num,
step=draft_num,
dtype=torch.int32,
device=device,
)
kv_indptr = self.kv_indptr
kv_indptr[1 : bs + 1] = torch.cumsum(kv_lens, dim=0)
kv_indptr = kv_indptr[: bs + 1]
kv_indices = torch.empty(
kv_lens_sum,
dtype=torch.int32,
device=device,
)
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
forward_batch.req_pool_indices,
kv_lens,
kv_indptr,
None,
kv_indices,
self.req_to_token.stride(0),
)
self.forward_metadata = ForwardMetadata(
kv_indptr,
kv_indices,
qo_indptr,
# self.mla_indices_updater_prefill.kv_last_page_len,
self.kv_last_page_len[:bs],
draft_num,
None,
)
else:
self.indices_updater_prefill.update(
forward_batch.req_pool_indices,
forward_batch.seq_lens,
forward_batch.seq_lens_sum,
prefix_lens=None,
encoder_lens=forward_batch.encoder_lens,
spec_info=forward_batch.spec_info,
)
self.forward_metadata = ForwardMetadata(
self.indices_updater_prefill.kv_indptr,
self.indices_updater_prefill.kv_indices,
None,
None,
self.indices_updater_prefill.max_q_len,
self.indices_updater_prefill.max_kv_len,
)
else:
prefix_lens = forward_batch.extend_prefix_lens
if self.is_multimodal:
extend_no_prefix = False
else:
extend_no_prefix = not any(forward_batch.extend_prefix_lens_cpu)
if self.use_mla:
self.mla_indices_updater_prefill.update(
forward_batch.req_pool_indices,
forward_batch.seq_lens,
forward_batch.seq_lens_sum,
forward_batch.extend_seq_lens,
forward_batch.extend_seq_lens.max().item(),
forward_batch.seq_lens.max().item(),
spec_info=None,
)
kv_indices = self.mla_indices_updater_prefill.kv_indices
self.forward_metadata = ForwardMetadata(
self.mla_indices_updater_prefill.kv_indptr,
kv_indices,
self.mla_indices_updater_prefill.qo_indptr,
self.kv_last_page_len[:bs],
self.mla_indices_updater_prefill.max_q_len,
self.mla_indices_updater_prefill.max_kv_len,
)
else:
self.indices_updater_prefill.update(
forward_batch.req_pool_indices,
forward_batch.seq_lens,
forward_batch.seq_lens_sum,
prefix_lens,
encoder_lens=forward_batch.encoder_lens,
spec_info=None,
)
self.forward_metadata = ForwardMetadata(
self.indices_updater_prefill.kv_indptr,
self.indices_updater_prefill.kv_indices,
None,
None,
self.indices_updater_prefill.max_q_len,
self.indices_updater_prefill.max_kv_len,
)
def init_cuda_graph_state(
self,
max_bs: int,
max_num_tokens: int,
kv_indices_buf: Optional[torch.Tensor] = None,
):
self.cuda_graph_kv_last_page_len = torch.ones(max_bs, dtype=torch.int)
if kv_indices_buf is None:
self.cuda_graph_kv_indices = torch.zeros(
(max_bs * self.max_context_len),
dtype=torch.int32,
device=self.device,
)
else:
self.cuda_graph_kv_indices = kv_indices_buf
if not self.skip_prefill:
self.cuda_graph_custom_mask = torch.zeros(
(max_num_tokens * self.max_context_len),
dtype=torch.uint8,
device=self.device,
)
def init_forward_metadata_capture_cuda_graph(
self,
bs: int,
num_tokens: int,
req_pool_indices: torch.Tensor,
seq_lens: torch.Tensor,
encoder_lens: Optional[torch.Tensor],
forward_mode: ForwardMode,
spec_info: Optional[SpecInfo],
):
if forward_mode.is_decode_or_idle():
qo_indptr = None
kv_last_page_len = None
max_q_len = None
if spec_info is None:
kv_indptr = self.kv_indptr
kv_indptr[1 : bs + 1] = torch.cumsum(seq_lens, dim=0)
kv_indptr = kv_indptr[: bs + 1]
kv_indices = self.cuda_graph_kv_indices
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
req_pool_indices,
seq_lens,
kv_indptr,
None,
kv_indices,
self.req_to_token.stride(0),
)
else:
kv_indptr, kv_indices = spec_info.kv_indptr, spec_info.kv_indices
if self.use_mla:
qo_indptr = self.qo_indptr_[: bs + 1]
qo_indptr[1 : bs + 1] = torch.cumsum(
self.cuda_graph_kv_last_page_len[:bs], dim=0
)
kv_last_page_len = self.cuda_graph_kv_last_page_len[:bs]
max_q_len = 1
self.forward_metadata = ForwardMetadata(
kv_indptr,
kv_indices,
qo_indptr,
kv_last_page_len,
max_q_len,
None,
)
elif forward_mode.is_target_verify():
if self.use_mla:
qo_indptr = self.qo_indptr[: bs + 1]
qo_indptr[: bs + 1] = torch.arange(
0,
(1 + bs) * self.num_draft_tokens,
step=self.num_draft_tokens,
dtype=torch.int32,
device=self.device,
)
kv_indptr = self.kv_indptr[: bs + 1]
kv_indptr[1 : bs + 1] = torch.cumsum(seq_lens, dim=0)
kv_indices = self.cuda_graph_kv_indices
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
req_pool_indices,
seq_lens,
kv_indptr,
None,
kv_indices,
self.req_to_token.stride(0),
)
kv_last_page_len = self.cuda_graph_kv_last_page_len[:bs]
max_q_len = self.num_draft_tokens
self.forward_metadata = ForwardMetadata(
kv_indptr,
kv_indices,
qo_indptr,
kv_last_page_len,
max_q_len,
None,
)
else:
seq_lens_sum = seq_lens.sum().item()
self.indices_updater_prefill.update(
req_pool_indices,
seq_lens,
seq_lens_sum,
prefix_lens=None,
encoder_lens=encoder_lens,
spec_info=spec_info,
)
self.forward_metadata = ForwardMetadata(
self.indices_updater_prefill.kv_indptr,
self.indices_updater_prefill.kv_indices,
None,
None,
self.indices_updater_prefill.max_q_len,
self.indices_updater_prefill.max_kv_len,
)
elif forward_mode.is_draft_extend():
num_tokens_per_bs = self.speculative_num_steps + 1
qo_indptr = self.qo_indptr[: bs + 1]
qo_indptr[: bs + 1] = torch.arange(
0,
bs * num_tokens_per_bs + 1,
step=num_tokens_per_bs,
dtype=torch.int32,
device=self.device,
)
kv_indptr = self.kv_indptr[: bs + 1]
kv_indptr[1 : bs + 1] = torch.cumsum(seq_lens, dim=0)
kv_indices = self.cuda_graph_kv_indices
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
req_pool_indices,
seq_lens,
kv_indptr,
None,
kv_indices,
self.req_to_token.stride(0),
)
kv_last_page_len = self.cuda_graph_kv_last_page_len[:bs]
max_q_len = num_tokens_per_bs
self.forward_metadata = ForwardMetadata(
kv_indptr,
kv_indices,
qo_indptr,
kv_last_page_len,
max_q_len,
None,
)
else:
raise ValueError(f"Invalid mode: {forward_mode=}")
def init_forward_metadata_replay_cuda_graph(
self,
bs: int,
req_pool_indices: torch.Tensor,
seq_lens: torch.Tensor,
seq_lens_sum: int,
encoder_lens: Optional[torch.Tensor],
forward_mode: ForwardMode,
spec_info: Optional[SpecInfo],
seq_lens_cpu: Optional[torch.Tensor],
):
if forward_mode.is_decode_or_idle():
kv_indptr = self.kv_indptr
kv_indices = self.cuda_graph_kv_indices
if spec_info is None:
kv_indptr[1 : bs + 1] = torch.cumsum(seq_lens[:bs], dim=0)
kv_indptr = kv_indptr[: bs + 1]
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
req_pool_indices[:bs],
seq_lens[:bs],
kv_indptr,
None,
kv_indices,
self.req_to_token.stride(0),
)
else:
kv_indptr[: spec_info.kv_indptr.shape[0]] = spec_info.kv_indptr
kv_indices[: spec_info.kv_indices.shape[0]] = spec_info.kv_indices
elif forward_mode.is_target_verify():
bs = len(req_pool_indices)
qo_indptr = self.qo_indptr[: bs + 1]
qo_indptr[: bs + 1] = torch.arange(
0,
(1 + bs) * self.num_draft_tokens,
step=self.num_draft_tokens,
dtype=torch.int32,
device=self.device,
)
kv_lens = seq_lens + self.num_draft_tokens
kv_indptr = self.kv_indptr[: bs + 1]
kv_indptr[1 : bs + 1] = torch.cumsum(kv_lens, dim=0)
kv_indices = self.cuda_graph_kv_indices
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
req_pool_indices,
kv_lens,
kv_indptr,
None,
kv_indices,
self.req_to_token.stride(0),
)
elif forward_mode.is_draft_extend():
seq_lens = seq_lens[:bs]
accept_lens = spec_info.accept_length[:bs]
qo_indptr = self.qo_indptr[: bs + 1]
qo_indptr[1 : bs + 1] = torch.cumsum(accept_lens, dim=0)
kv_indptr = self.kv_indptr[: bs + 1]
kv_indptr[1 : bs + 1] = torch.cumsum(seq_lens, dim=0)
kv_indices = self.cuda_graph_kv_indices
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
req_pool_indices,
seq_lens,
kv_indptr,
None,
kv_indices,
self.req_to_token.stride(0),
)
else:
raise ValueError("Invalid forward mode")
def get_cuda_graph_seq_len_fill_value(self):
return 1
def forward_extend(
self,
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
layer: RadixAttention,
forward_batch: ForwardBatch,
save_kv_cache=True,
):
cache_loc = (
forward_batch.out_cache_loc
if not layer.is_cross_attention
else forward_batch.encoder_out_cache_loc
)
self.logits_soft_cap = layer.logit_cap
if k is not None:
assert v is not None
if save_kv_cache:
if self.use_mla:
forward_batch.token_to_kv_pool.set_kv_buffer(layer, cache_loc, k, v)
else:
forward_batch.token_to_kv_pool.set_kv_buffer(
layer, cache_loc, k, v, layer.k_scale, layer.v_scale
)
if self.use_mla:
max_q_len = self.forward_metadata.max_q_len
max_kv_len = self.forward_metadata.max_kv_len
kv_indptr = self.forward_metadata.kv_indptr
kv_indices = self.forward_metadata.kv_indices
qo_indptr = self.forward_metadata.qo_indptr
K_Buffer = forward_batch.token_to_kv_pool.get_key_buffer(layer.layer_id)
V_Buffer = forward_batch.token_to_kv_pool.get_value_buffer(layer.layer_id)
kv_lora_rank = V_Buffer.shape[-1]
qk_rope_head_dim = K_Buffer.shape[-1] - kv_lora_rank
qk_nope_head_dim = k.shape[-1] - qk_rope_head_dim
assert len(q.shape) == 3
assert len(k.shape) == 3
assert len(v.shape) == 3
if (
forward_batch.forward_mode.is_extend()
and not forward_batch.forward_mode.is_target_verify()
and not forward_batch.forward_mode.is_draft_extend()
):
if kv_indices.shape[0] == 0:
o = flash_attn_varlen_func(
q,
k,
v,
qo_indptr,
qo_indptr,
max_q_len,
max_q_len,
softmax_scale=layer.scaling,
causal=True,
)
return o
elif layer.qk_head_dim != (kv_lora_rank + qk_rope_head_dim):
K_Buffer = torch.index_select(K_Buffer, 0, kv_indices)
kvc, k_pe = torch.split(
K_Buffer, [kv_lora_rank, qk_rope_head_dim], dim=-1
)
kvprefix = layer.kv_b_proj(kvc.contiguous())[0]
kvprefix = kvprefix.view(
-1, layer.tp_k_head_num, qk_nope_head_dim + layer.v_head_dim
)
k_prefix, v_prefix = torch.split(
kvprefix, [qk_nope_head_dim, layer.v_head_dim], dim=-1
)
k_prefix = torch.cat(
[
k_prefix,
torch.broadcast_to(
k_pe,
(k_pe.shape[0], layer.tp_k_head_num, k_pe.shape[2]),
),
],
dim=-1,
)
assert (
forward_batch.extend_prefix_lens.shape
== forward_batch.extend_seq_lens.shape
)
k = k_prefix
v = v_prefix
o = flash_attn_varlen_func(
q,
k,
v,
qo_indptr,
kv_indptr,
max_q_len,
max_kv_len,
softmax_scale=layer.scaling,
causal=True,
)
return o
else:
if layer.qk_head_dim != layer.v_head_dim:
o = q.new_empty(
(q.shape[0], layer.tp_q_head_num * layer.v_head_dim)
)
else:
o = torch.empty_like(q)
mla_prefill_fwd(
q.view(-1, layer.tp_q_head_num, layer.qk_head_dim),
K_Buffer.view(-1, 1, 1, layer.qk_head_dim),
o.view(-1, layer.tp_q_head_num, layer.v_head_dim),
qo_indptr,
kv_indptr,
kv_indices,
self.forward_metadata.kv_last_page_len,
self.forward_metadata.max_q_len,
layer.scaling,
layer.logit_cap,
)
K_Buffer = K_Buffer.view(-1, layer.tp_k_head_num, layer.qk_head_dim)
return o
elif forward_batch.forward_mode.is_target_verify():
o = q.new_empty((q.shape[0], layer.tp_q_head_num, layer.v_head_dim))
mla_decode_fwd(
q,
K_Buffer.view(-1, 1, 1, layer.qk_head_dim),
o,
self.forward_metadata.qo_indptr,
self.forward_metadata.kv_indptr,
self.forward_metadata.kv_indices,
self.forward_metadata.kv_last_page_len,
self.forward_metadata.max_q_len,
layer.scaling,
layer.logit_cap,
)
K_Buffer = K_Buffer.view(-1, 1, layer.qk_head_dim)
return o
elif forward_batch.forward_mode.is_draft_extend():
o = q.new_empty((q.shape[0], layer.tp_q_head_num, layer.v_head_dim))
causal = True
sliding_window_size = -1
kv_indptr = self.forward_metadata.kv_indptr
kv_indices = self.forward_metadata.kv_indices
mla_prefill_fwd(
q,
K_Buffer.view(-1, 1, 1, layer.qk_head_dim),
o,
self.forward_metadata.qo_indptr,
self.forward_metadata.kv_indptr,
self.forward_metadata.kv_indices,
self.forward_metadata.kv_last_page_len,
self.forward_metadata.max_q_len,
layer.scaling,
layer.logit_cap,
)
K_Buffer = K_Buffer.view(-1, 1, layer.qk_head_dim)
return o
# self.extend_attention_fwd(
# q.view(-1, layer.tp_q_head_num, layer.qk_head_dim),
# k.contiguous(),
# v.contiguous(),
# o.view(-1, layer.tp_q_head_num, layer.v_head_dim),
# forward_batch.token_to_kv_pool.get_key_buffer(layer.layer_id),
# forward_batch.token_to_kv_pool.get_value_buffer(layer.layer_id),
# self.forward_metadata.qo_indptr,
# kv_indptr,
# kv_indices,
# None,
# causal,
# None,
# self.forward_metadata.max_q_len,
# layer.scaling,
# layer.logit_cap,
# sliding_window_size,
# )
# return o
else:
raise ValueError(
f"Invalid forward mode for MLA prefill: {forward_batch.forward_mode=}"
)
else:
k_cache, v_cache = forward_batch.token_to_kv_pool.get_kv_buffer(
layer.layer_id
)
bs0 = forward_batch.batch_size + 1
o = mha_batch_prefill_func(
q.contiguous().view(-1, layer.tp_q_head_num, layer.head_dim),
k_cache,
v_cache,
self.qo_indptr[:bs0],
self.forward_metadata.kv_indptr[:bs0],
self.forward_metadata.kv_indices,
self.forward_metadata.max_q_len,
self.forward_metadata.max_kv_len,
causal=True,
logits_soft_cap=self.logits_soft_cap,
alibi_slopes=None,
return_lse=False,
return_attn_probs=False,
)
return o.view(-1, layer.tp_q_head_num * layer.head_dim)
def forward_decode(
self,
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
layer: RadixAttention,
forward_batch: ForwardBatch,
save_kv_cache=True,
):
q = q.reshape(-1, layer.tp_q_head_num * layer.qk_head_dim)
if layer.qk_head_dim != layer.v_head_dim:
o = q.new_empty((q.shape[0], layer.tp_q_head_num * layer.v_head_dim))
else:
o = torch.empty_like(q)
if save_kv_cache:
forward_batch.token_to_kv_pool.set_kv_buffer(
layer, forward_batch.out_cache_loc, k, v
)
if self.use_mla:
k_buffer = forward_batch.token_to_kv_pool.get_key_buffer(layer.layer_id)
mla_decode_fwd(
q.view(-1, layer.tp_q_head_num, layer.qk_head_dim),
k_buffer.view(-1, 1, 1, layer.qk_head_dim),
o.view(-1, layer.tp_q_head_num, layer.v_head_dim),
self.forward_metadata.qo_indptr,
self.forward_metadata.kv_indptr,
self.forward_metadata.kv_indices,
self.forward_metadata.kv_last_page_len,
self.forward_metadata.max_q_len,
layer.scaling,
layer.logit_cap,
)
k_buffer = k_buffer.view(-1, 1, layer.qk_head_dim)
else:
self.logits_soft_cap = layer.logit_cap
paged_attention_ragged(
o.view(-1, layer.tp_q_head_num, layer.qk_head_dim),
self.workspace_buffer,
q.view(-1, layer.tp_q_head_num, layer.qk_head_dim),
forward_batch.token_to_kv_pool.get_key_buffer(layer.layer_id).view(
-1, 1, layer.tp_k_head_num, layer.qk_head_dim
),
forward_batch.token_to_kv_pool.get_value_buffer(layer.layer_id).view(
-1, 1, layer.tp_v_head_num, layer.v_head_dim
),
self.scale,
self.forward_metadata.kv_indptr,
self.forward_metadata.kv_indices,
self.kv_last_page_len,
1,
self.max_num_partitions,
None,
"auto",
"NHD",
self.logits_soft_cap,
self.k_scale,
self.v_scale,
None,
_AITER_PARTITION_SIZE_ROCM,
)
return o
class AiterIndicesUpdaterPrefill:
def __init__(self, model_runner: ModelRunner, attn_backend: AttentionBackend):
# Parse Constants
self.num_qo_heads = (
model_runner.model_config.num_attention_heads // get_attention_tp_size()
)
self.num_kv_heads = model_runner.model_config.get_num_kv_heads(
get_attention_tp_size()
)
self.head_dim = model_runner.model_config.head_dim
self.data_type = model_runner.kv_cache_dtype
self.q_data_type = model_runner.dtype
self.sliding_window_size = model_runner.sliding_window_size
self.attn_backend = attn_backend
# Buffers and wrappers
self.kv_indptr = attn_backend.kv_indptr
self.kv_last_page_len = attn_backend.kv_last_page_len
self.qo_indptr = attn_backend.qo_indptr
self.req_to_token = model_runner.req_to_token_pool.req_to_token
self.update = self.update_single_wrapper
self.kv_indices = None
self.max_q_len = 0
self.max_kv_len = 0
def update(
self,
req_pool_indices: torch.Tensor,
seq_lens: torch.Tensor,
seq_lens_sum: int,
prefix_lens: torch.Tensor,
encoder_lens: Optional[torch.Tensor],
spec_info: Optional[SpecInfo],
):
# Keep the signature for type checking. It will be assigned during runtime.
raise NotImplementedError()
def update_single_wrapper(
self,
req_pool_indices: torch.Tensor,
seq_lens: torch.Tensor,
seq_lens_sum: int,
prefix_lens: torch.Tensor,
encoder_lens: Optional[torch.Tensor],
spec_info: Optional[SpecInfo],
):
kv_start_idx = None
kv_indptr = self.kv_indptr
qo_indptr = self.qo_indptr
paged_kernel_lens = seq_lens
paged_kernel_lens_sum = seq_lens_sum
bs = len(req_pool_indices)
if spec_info is None:
# Normal extend
kv_indptr[1 : bs + 1] = torch.cumsum(paged_kernel_lens, dim=0)
kv_indptr = kv_indptr[: bs + 1]
# (TODO: Kk) WA - CI test_moe_eval_accuracy_large.py
# mha_batch_prefill reads 128 data to do computatoin
# if real data is not long enough then original padding value 0 is used
# but the 0 location will be made nan (noqa) in cuda graph capture mode
# this will cause the output tensor value becomes nan
# WA is to assure that last index of pool not changed
kv_indices = torch.empty(
paged_kernel_lens_sum + 256,
dtype=torch.int32,
device=req_pool_indices.device,
)
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
req_pool_indices,
paged_kernel_lens,
kv_indptr,
kv_start_idx,
kv_indices,
self.req_to_token.shape[1],
)
token_num = kv_indptr[-1]
kv_indices[token_num:] = kv_indices[0]
self.max_kv_len = torch.max(paged_kernel_lens).item()
extend_lens = seq_lens - prefix_lens
self.max_q_len = torch.max(extend_lens).item()
qo_indptr[1 : bs + 1] = torch.cumsum(extend_lens, dim=0)
qo_indptr = qo_indptr[: bs + 1]
custom_mask = None
else:
kv_indices, kv_indptr, qo_indptr, custom_mask = (
spec_info.generate_attn_arg_prefill(
req_pool_indices,
paged_kernel_lens,
paged_kernel_lens_sum,
self.req_to_token,
)
)
self.kv_indices = kv_indices
class AiterMlaIndicesUpdaterPrefill:
def __init__(self, model_runner: ModelRunner, attn_backend: AttentionBackend):
# Parse Constants
self.attn_backend = attn_backend
# Buffers and wrappers
self.req_to_token = model_runner.req_to_token_pool.req_to_token
self.update = self.update_single_wrapper
self.kv_indptr = None
self.kv_indices = None
self.qo_indptr = None
self.kv_last_page_len = None
self.max_q_len = 0
self.max_kv_len = 0
def update(
self,
req_pool_indices: torch.Tensor,
kv_lens: torch.Tensor,
kv_lens_sum: int,
extend_lens: torch.Tensor,
max_q_len: int,
max_kv_len: int,
spec_info: Optional[SpecInfo],
):
# Keep the signature for type checking. It will be assigned during runtime.
raise NotImplementedError()
def update_single_wrapper(
self,
req_pool_indices: torch.Tensor,
kv_lens: torch.Tensor,
kv_lens_sum: int,
extend_lens: torch.Tensor,
max_q_len: int,
max_kv_len: int,
spec_info: Optional[SpecInfo],
):
bs = len(req_pool_indices)
kv_indptr = self.attn_backend.kv_indptr
if spec_info is None:
# Normal extend
kv_indptr[1 : bs + 1] = torch.cumsum(kv_lens, dim=0)
kv_indptr = kv_indptr[: bs + 1]
kv_indices = torch.empty(
kv_lens_sum,
dtype=torch.int32,
device=req_pool_indices.device,
)
create_flashinfer_kv_indices_triton[(bs,)](
self.req_to_token,
req_pool_indices,
kv_lens,
kv_indptr,
None,
kv_indices,
self.req_to_token.stride(0),
)
qo_indptr = self.attn_backend.qo_indptr
qo_indptr[1 : bs + 1] = torch.cumsum(extend_lens, dim=0)
qo_indptr = qo_indptr[: bs + 1]
else:
kv_indices, kv_indptr, qo_indptr, custom_mask = (
spec_info.generate_attn_arg_prefill(
req_pool_indices,
kv_lens,
kv_lens_sum,
self.req_to_token,
)
)
self.kv_indptr = kv_indptr
self.kv_indices = kv_indices
self.qo_indptr = qo_indptr
self.max_q_len = max_q_len
self.max_kv_len = max_kv_len
class AiterMultiStepDraftBackend:
"""
Wrap multiple triton attention backends as one for multiple consecutive
draft decoding steps.
"""
def __init__(
self,
model_runner: ModelRunner,
topk: int,
speculative_num_steps: int,
):
from sglang.srt.speculative.eagle_utils import generate_draft_decode_kv_indices
self.topk = topk
self.speculative_num_steps = speculative_num_steps
self.generate_draft_decode_kv_indices = generate_draft_decode_kv_indices
max_bs = model_runner.req_to_token_pool.size * self.topk
self.kv_indptr = torch.zeros(
(
self.speculative_num_steps,
max_bs + 1,
),
dtype=torch.int32,
device=model_runner.device,
)
self.attn_backends = []
for i in range(self.speculative_num_steps):
self.attn_backends.append(
AiterAttnBackend(
model_runner,
skip_prefill=True,
kv_indptr_buf=self.kv_indptr[i],
)
)
self.max_context_len = self.attn_backends[0].max_context_len
self.num_head = (
model_runner.model_config.num_attention_heads // get_attention_tp_size()
)
self.device = model_runner.device
# Cached variables for generate_draft_decode_kv_indices
self.pool_len = model_runner.req_to_token_pool.req_to_token.shape[1]
self.page_size = model_runner.server_args.page_size
assert self.page_size == 1, "Page size must be 1"
def common_template(
self, forward_batch: ForwardBatch, kv_indices_buffer: torch.Tensor, call_fn: int
):
num_seqs = forward_batch.batch_size
bs = self.topk * num_seqs
seq_lens_sum = forward_batch.seq_lens_sum
self.generate_draft_decode_kv_indices[
(self.speculative_num_steps, num_seqs, self.topk)
](
forward_batch.req_pool_indices,
forward_batch.req_to_token_pool.req_to_token,
forward_batch.seq_lens,
kv_indices_buffer,
self.kv_indptr,
forward_batch.positions,
self.pool_len,
kv_indices_buffer.shape[1],
self.kv_indptr.shape[1],
triton.next_power_of_2(num_seqs),
triton.next_power_of_2(self.speculative_num_steps),
triton.next_power_of_2(bs),
self.page_size,
)
for i in range(self.speculative_num_steps):
forward_batch.spec_info.kv_indptr = self.kv_indptr[i, : bs + 1]
forward_batch.spec_info.kv_indices = kv_indices_buffer[i][
: seq_lens_sum * self.topk + bs * (i + 1)
]
call_fn(i, forward_batch)
def init_forward_metadata(self, forward_batch: ForwardBatch):
kv_indices = torch.empty(
(
self.speculative_num_steps,
forward_batch.batch_size * self.topk * self.max_context_len,
),
dtype=torch.int32,
device=self.device,
)
def call_fn(i, forward_batch):
forward_batch.spec_info.kv_indptr = (
forward_batch.spec_info.kv_indptr.clone()
)
forward_batch.spec_info.kv_indices = (
forward_batch.spec_info.kv_indices.clone()
)
self.attn_backends[i].init_forward_metadata(forward_batch)
self.common_template(forward_batch, kv_indices, call_fn)
def init_cuda_graph_state(self, max_bs: int, max_num_tokens: int):
self.cuda_graph_kv_indices = torch.zeros(
(self.speculative_num_steps, max_num_tokens * self.max_context_len),
dtype=torch.int32,
device=self.device,
)
for i in range(self.speculative_num_steps):
self.attn_backends[i].init_cuda_graph_state(
max_bs, max_num_tokens, kv_indices_buf=self.cuda_graph_kv_indices[i]
)
def init_forward_metadata_capture_cuda_graph(self, forward_batch: ForwardBatch):
def call_fn(i, forward_batch):
self.attn_backends[i].init_forward_metadata_capture_cuda_graph(
forward_batch.batch_size,
forward_batch.batch_size * self.topk,
forward_batch.req_pool_indices,
forward_batch.seq_lens,
encoder_lens=None,
forward_mode=ForwardMode.DECODE,
spec_info=forward_batch.spec_info,
)
self.common_template(forward_batch, self.cuda_graph_kv_indices, call_fn)
def init_forward_metadata_replay_cuda_graph(
self, forward_batch: ForwardBatch, bs: int
):
def call_fn(i, forward_batch):
self.attn_backends[i].init_forward_metadata_replay_cuda_graph(
bs,
forward_batch.req_pool_indices,
forward_batch.seq_lens,
seq_lens_sum=-1,
encoder_lens=None,
forward_mode=ForwardMode.DECODE,
spec_info=forward_batch.spec_info,
seq_lens_cpu=None,
)
self.common_template(forward_batch, self.cuda_graph_kv_indices, call_fn)