[Feature] add model aware kv ops helper (#16020)

Signed-off-by: billishyahao <bill.he@amd.com>
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billishyahao 2025-04-16 14:00:43 +08:00 committed by GitHub
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commit 3ac98edcb1
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3 changed files with 121 additions and 99 deletions

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@ -1,7 +1,6 @@
# SPDX-License-Identifier: Apache-2.0
"""
MooncakeStore Connector for Distributed Machine Learning Inference
The MooncakeStoreConnector transfers KV caches between prefill vLLM workers
(KV cache producer) and decode vLLM workers (KV cache consumer) using a
database-style KVStore.
@ -11,9 +10,10 @@ from typing import TYPE_CHECKING, List, Tuple, Union
import torch
from vllm import _custom_ops as ops
from vllm.config import VllmConfig
from vllm.distributed.kv_transfer.kv_connector.base import KVConnectorBase
from vllm.distributed.kv_transfer.kv_connector.utils import (
model_aware_kv_ops_helper as kv_helper)
from vllm.logger import init_logger
from vllm.sequence import IntermediateTensors
@ -32,8 +32,7 @@ class MooncakeStoreConnector(KVConnectorBase):
config: VllmConfig,
):
self.config = config.kv_transfer_config
self.tp_size = config.parallel_config.tensor_parallel_size
self.kv_helper = kv_helper(config)
self.local_tp_rank = local_rank
# Init kv_store
@ -80,12 +79,7 @@ class MooncakeStoreConnector(KVConnectorBase):
slot_mapping_flat = model_input.attn_metadata.slot_mapping.flatten()
start_layer = model_executable.model.start_layer
end_layer = model_executable.model.end_layer
model_config = model_executable.model.config
num_heads = int(model_config.num_key_value_heads / self.tp_size)
hidden_size = model_config.hidden_size
num_attention_heads = model_config.num_attention_heads
head_size = int(hidden_size / num_attention_heads)
num_heads, head_size = self.kv_helper.get_model_args(model_executable)
for idx, slen in enumerate(seq_lens):
start_pos = sum(seq_lens[:idx])
@ -97,10 +91,8 @@ class MooncakeStoreConnector(KVConnectorBase):
for layer_id in range(start_layer, end_layer):
kv_cache = kv_caches[layer_id - start_layer]
key_cache = kv_cache[0].reshape(-1, num_heads, head_size)
value_cache = kv_cache[1].reshape(-1, num_heads, head_size)
key_cache, value_cache = self.kv_helper.get_kv_from_cache(
kv_cache, num_heads, head_size)
current_slot_mapping = slot_mapping_flat[start_pos:end_pos]
keys.append(key_cache[current_slot_mapping].unsqueeze(0))
@ -173,22 +165,15 @@ class MooncakeStoreConnector(KVConnectorBase):
layer = model_executable.model.layers[layer_id]
# get kvcache object
kv_cache = kv_caches[layer_id - start_layer]
key_cache, value_cache = kv_cache[0], kv_cache[1]
# get remote kvcache
# get remote kvcache
remote_k, remote_v = remote_kv[0][layer_id], remote_kv[1][
layer_id]
# use ops.reshape_and_cache_flash to put kv into kvcache
ops.reshape_and_cache_flash(
remote_k.to(key_cache.device),
remote_v.to(value_cache.device),
key_cache,
value_cache,
slot_mapping[start_pos:end_pos],
layer.self_attn.attn.kv_cache_dtype,
layer.self_attn.attn._k_scale,
layer.self_attn.attn._v_scale,
)
self.kv_helper.put_kv_to_cache(model_executable, remote_k,
remote_v, layer, kv_cache,
slot_mapping, start_pos,
end_pos)
hidden_or_intermediate_states_for_one_req.append(hidden)

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@ -12,10 +12,10 @@ from typing import TYPE_CHECKING, List, Optional, Tuple, Union
import torch
import vllm.envs as envs
from vllm import _custom_ops as ops
from vllm.config import VllmConfig
from vllm.distributed.kv_transfer.kv_connector.base import KVConnectorBase
from vllm.distributed.kv_transfer.kv_connector.utils import (
model_aware_kv_ops_helper as kv_helper)
from vllm.distributed.kv_transfer.kv_lookup_buffer.simple_buffer import (
SimpleBuffer)
from vllm.logger import init_logger
@ -37,9 +37,7 @@ class SimpleConnector(KVConnectorBase):
):
self.config = config.kv_transfer_config
self.tp_size = config.parallel_config.tensor_parallel_size
self.is_deepseek_mla = config.model_config.is_deepseek_mla
self.use_mla_opt = not envs.VLLM_MLA_DISABLE
self.kv_helper = kv_helper(config)
if self.config.kv_connector == "PyNcclConnector":
from vllm.distributed.kv_transfer.kv_pipe.pynccl_pipe import (
@ -165,31 +163,7 @@ class SimpleConnector(KVConnectorBase):
num_prefill_tokens = model_input.attn_metadata.num_prefill_tokens
start_layer = model_executable.model.start_layer
end_layer = model_executable.model.end_layer
model_config = model_executable.model.config
num_heads = int(model_config.num_key_value_heads / self.tp_size)
hidden_size = model_config.hidden_size
num_attention_heads = model_config.num_attention_heads
# Deepseek's MLA (Multi-head Latent Attention) uses two different
# kv_cache shapes based on whether VLLM_MLA_DISABLE is set to 0.
# When VLLM_MLA_DISABLE=0 (default), forward absorb is applied,
# resulting in a kv_cache shape of [num_blks, blk_size, 1,
# kv_lora_rank + qk_rope_head_dim].
# When VLLM_MLA_DISABLE=1, standard FA is used instead, leading
# to a kv_cache shape of [2, num_blks, blk_size,
# num_key_value_heads / tp, qk_nope_head_dim + qk_rope_head_dim].
# For more details, see vllm/attention/backends/mla/common.py.
if self.is_deepseek_mla and self.use_mla_opt:
head_size = model_config.kv_lora_rank + \
model_config.qk_rope_head_dim
num_heads = 1
elif self.is_deepseek_mla and not self.use_mla_opt:
head_size = model_config.qk_nope_head_dim + \
model_config.qk_rope_head_dim
else:
head_size = getattr(model_config, "head_dim",
int(hidden_size // num_attention_heads))
num_heads, head_size = self.kv_helper.get_model_args(model_executable)
# query_lens contains new KV caches that are added to vLLM.
# so we will send them to decode instance
@ -212,13 +186,8 @@ class SimpleConnector(KVConnectorBase):
for layer_id in range(start_layer, end_layer):
kv_cache = kv_caches[layer_id - start_layer]
if self.is_deepseek_mla and self.use_mla_opt:
key_cache = kv_cache.reshape(-1, num_heads, head_size)
value_cache = kv_cache.reshape(-1, num_heads, head_size)
else:
key_cache = kv_cache[0].reshape(-1, num_heads, head_size)
value_cache = kv_cache[1].reshape(-1, num_heads, head_size)
key_cache, value_cache = self.kv_helper.get_kv_from_cache(
kv_cache, num_heads, head_size)
current_slot_mapping = slot_mapping_flat[start_pos:end_pos]
@ -248,12 +217,12 @@ class SimpleConnector(KVConnectorBase):
# and hidden states.
bypass_model_exec = True
model_config = model_executable.model.config
input_tokens_tensor = model_input.input_tokens
seq_lens = model_input.attn_metadata.seq_lens
num_prefill_tokens = model_input.attn_metadata.num_prefill_tokens
slot_mapping = model_input.attn_metadata.slot_mapping.flatten()
start_layer = model_executable.model.start_layer
end_layer = model_executable.model.end_layer
hidden_or_intermediate_states_for_one_req = []
@ -312,41 +281,19 @@ class SimpleConnector(KVConnectorBase):
end_pos = start_pos + num_computed_tokens
# put received KV caches into paged memory
for i in range(model_executable.model.start_layer,
model_executable.model.end_layer):
for cur_layer in range(start_layer, end_layer):
kv_cache = kv_caches[i - model_executable.model.start_layer]
layer = model_executable.model.layers[i]
layer_id = cur_layer - start_layer
kv_cache = kv_caches[layer_id]
layer = model_executable.model.layers[cur_layer]
if self.is_deepseek_mla and self.use_mla_opt:
layer.self_attn.attn = layer.self_attn.mla_attn
k_c_normed_k_pe = keys[
i - model_executable.model.start_layer].to(
kv_cache.device).squeeze(1)
k_c_normed = k_c_normed_k_pe[:, :model_config.kv_lora_rank]
k_pe = k_c_normed_k_pe[:, model_config.kv_lora_rank:]
ops.concat_and_cache_mla(
k_c_normed,
k_pe,
kv_cache,
slot_mapping[start_pos:end_pos],
layer.self_attn.attn.kv_cache_dtype,
layer.self_attn.attn._k_scale,
)
else:
key_cache, value_cache = kv_cache[0], kv_cache[1]
ops.reshape_and_cache_flash(
keys[i - model_executable.model.start_layer].to(
key_cache.device),
values[i - model_executable.model.start_layer].to(
value_cache.device),
key_cache,
value_cache,
slot_mapping[start_pos:end_pos],
layer.self_attn.attn.kv_cache_dtype,
layer.self_attn.attn._k_scale,
layer.self_attn.attn._v_scale,
)
# get remote kvcache
remote_k, remote_v = keys[layer_id], values[layer_id]
self.kv_helper.put_kv_to_cache(model_executable, remote_k,
remote_v, layer, kv_cache,
slot_mapping, start_pos,
end_pos)
hidden_or_intermediate_states_for_one_req.append(hidden)

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@ -0,0 +1,90 @@
# SPDX-License-Identifier: Apache-2.0
"""
KV cache helper for store.
"""
import torch
import vllm.envs as envs
from vllm import _custom_ops as ops
from vllm.config import VllmConfig
from vllm.logger import init_logger
logger = init_logger(__name__)
class model_aware_kv_ops_helper:
def __init__(self, config: VllmConfig):
self.is_deepseek_mla = config.model_config.is_deepseek_mla
self.use_mla_opt = not envs.VLLM_MLA_DISABLE
self.tp_size = config.parallel_config.tensor_parallel_size
def get_model_args(self, model_executable: torch.nn.Module):
model_config = model_executable.model.config
self.model_executable = model_executable
num_heads = int(model_config.num_key_value_heads / self.tp_size)
hidden_size = model_config.hidden_size
num_attention_heads = model_config.num_attention_heads
# Deepseek's MLA (Multi-head Latent Attention) uses two different
# kv_cache shapes based on whether VLLM_MLA_DISABLE is set to 0.
# When VLLM_MLA_DISABLE=0 (default), forward absorb is applied,
# resulting in a kv_cache shape of [num_blks, blk_size, 1,
# kv_lora_rank + qk_rope_head_dim].
# When VLLM_MLA_DISABLE=1, standard FA is used instead, leading
# to a kv_cache shape of [2, num_blks, blk_size,
# num_key_value_heads / tp, qk_nope_head_dim + qk_rope_head_dim].
# For more details, see vllm/attention/backends/mla/common.py.
if self.is_deepseek_mla and self.use_mla_opt:
head_size = model_config.kv_lora_rank + \
model_config.qk_rope_head_dim
num_heads = 1
elif self.is_deepseek_mla and not self.use_mla_opt:
head_size = model_config.qk_nope_head_dim + \
model_config.qk_rope_head_dim
else:
head_size = getattr(model_config, "head_dim",
int(hidden_size // num_attention_heads))
return num_heads, head_size
def get_kv_from_cache(self, kv_cache, num_heads, head_size):
if self.is_deepseek_mla and self.use_mla_opt:
key_cache = kv_cache.reshape(-1, num_heads, head_size)
value_cache = kv_cache.reshape(-1, num_heads, head_size)
else:
key_cache = kv_cache[0].reshape(-1, num_heads, head_size)
value_cache = kv_cache[1].reshape(-1, num_heads, head_size)
return key_cache, value_cache
def put_kv_to_cache(self, model_executable: torch.nn.Module, keys, values,
layer, kv_cache, slot_mapping, start_pos, end_pos):
model_config = model_executable.model.config
if self.is_deepseek_mla and self.use_mla_opt:
layer.self_attn.attn = layer.self_attn.mla_attn
k_c_normed_k_pe = keys.squeeze(1)
k_c_normed = k_c_normed_k_pe[:, :model_config.kv_lora_rank]
k_pe = k_c_normed_k_pe[:, model_config.kv_lora_rank:]
ops.concat_and_cache_mla(
k_c_normed.to(kv_cache.device),
k_pe.to(kv_cache.device),
kv_cache,
slot_mapping[start_pos:end_pos],
layer.self_attn.attn.kv_cache_dtype,
layer.self_attn.attn._k_scale,
)
else:
key_cache, value_cache = kv_cache[0], kv_cache[1]
ops.reshape_and_cache_flash(
keys.to(key_cache.device),
values.to(value_cache.device),
key_cache,
value_cache,
slot_mapping[start_pos:end_pos],
layer.self_attn.attn.kv_cache_dtype,
layer.self_attn.attn._k_scale,
layer.self_attn.attn._v_scale,
)