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chore: import upstream snapshot with attribution
2026-07-13 13:23:58 +08:00

668 lines
26 KiB
Python

"""Implementation for Gemma3 architecture."""
import dataclasses
from typing import Any, Dict, Optional # noqa: UP035
from tvm import tirx
from tvm.relax.frontend import nn
from tvm.relax.frontend.nn import Tensor, op
from mlc_llm import op as op_ext
from mlc_llm.model.gemma.gemma_model import GemmaEmbedding
from mlc_llm.model.model_utils import index_last_token
from mlc_llm.nn import PagedKVCache, RopeMode
from mlc_llm.support import logging
from mlc_llm.support import tensor_parallel as tp
from mlc_llm.support.config import ConfigBase
from mlc_llm.support.style import bold
logger = logging.getLogger(__name__)
@dataclasses.dataclass
class Gemma3TextConfig(ConfigBase):
"""Configuration of the text model inside Gemma3"""
# NOTE More fields have defaults due to Huggingface Gemma3 configs missing fields
# The defaults for these fields can be found in the transformers library
hidden_size: int
intermediate_size: int
num_hidden_layers: int
attention_bias: bool = False
num_attention_heads: int = 8
num_key_value_heads: int = 4
head_dim: int = 256
rms_norm_eps: float = 1e-6
hidden_activation: Optional[str] = "gelu_pytorch_tanh"
position_embedding_base: int = 1_000_000
rope_scaling: int = 0
context_window_size: int = 131_072
prefill_chunk_size: int = 0
query_pre_attn_scalar: int = 256
sliding_window_size: int = None
sliding_window_pattern = 6
kwargs: Dict[str, Any] = dataclasses.field(default_factory=dict) # noqa: UP006
def __post_init__(self):
if self.hidden_activation is None:
self.hidden_activation = self.kwargs.get("hidden_act", None)
if self.sliding_window_size is None:
self.sliding_window_size = self.kwargs.get("sliding_window", None)
if self.hidden_activation not in ("gelu", "gelu_pytorch_tanh"):
raise ValueError("Only GeLU is supported as the activation for gemma.")
if self.attention_bias:
raise ValueError('Only "False" attention_bias is supported for gemma')
if self.position_embedding_base == 1000000 and "rope_theta" in self.kwargs:
self.position_embedding_base = self.kwargs.pop("rope_theta")
if self.context_window_size == 0:
for name in ["max_position_embeddings", "max_sequence_length"]:
if name in self.kwargs:
self.context_window_size = self.kwargs.pop(name)
logger.info(
"%s not found in config.json. Falling back to %s (%d)",
bold("context_window_size"),
bold(name),
self.context_window_size,
)
break
else:
raise ValueError(
"Unable to determine the maximum sequence length, because none of "
"`context_window_size`, `max_position_embeddings` or `max_sequence_length` is "
"provided in `config.json`."
)
assert self.num_attention_heads % self.num_key_value_heads == 0
if self.prefill_chunk_size == 0:
logger.info(
"%s defaults to %d",
bold("prefill_chunk_size"),
min(self.context_window_size, 8192),
)
self.prefill_chunk_size = min(self.context_window_size, 8192)
elif self.prefill_chunk_size > self.context_window_size:
logger.info(
"Overriding %s from %d to %d",
bold("prefill_chunk_size"),
self.prefill_chunk_size,
min(self.context_window_size, 8192),
)
self.prefill_chunk_size = min(self.context_window_size, 8192)
# NOTE: override the context window size with the Gemma2 sliding window size,
# as the sliding window attention every other layer is yet to be supported.
self.context_window_size = max(self.sliding_window_size, 8192)
@dataclasses.dataclass
class Gemma3Config(ConfigBase):
"""Configuration of the Gemma3 model"""
text_config: Gemma3TextConfig = None
vocab_size: int = 262_208
tensor_parallel_shards: int = 1
max_batch_size: int = 1
context_window_size: int = -1
sliding_window_size: int = -1
prefill_chunk_size: int = -1
is_text_model: bool = False
kwargs: Dict[str, Any] = dataclasses.field(default_factory=dict) # noqa: UP006
def __post_init__(self):
if self.text_config is None:
self.is_text_model = True
self.text_config = Gemma3TextConfig.from_dict(self.kwargs)
text_config_dict: Dict[str, Any] # noqa: UP006
if isinstance(self.text_config, Gemma3TextConfig):
text_config_dict = dataclasses.asdict(self.text_config)
else:
text_config_dict = dict(self.text_config)
for k, v in text_config_dict.pop("kwargs", {}).items():
text_config_dict[k] = v
self.text_config = Gemma3TextConfig.from_dict(text_config_dict)
for k in ["context_window_size", "prefill_chunk_size", "sliding_window_size"]:
if getattr(self, k) <= 0:
if hasattr(self.text_config, k):
setattr(self, k, getattr(self.text_config, k))
class Gemma3MLP(nn.Module):
def __init__(self, config: Gemma3Config):
super().__init__()
if config.text_config.intermediate_size % config.tensor_parallel_shards != 0:
raise ValueError(
f"Cannot split MLP intermediate size {config.text_config.intermediate_size} "
f"evenly to {config.tensor_parallel_shards} GPUs."
)
self.intermediate_size = (
config.text_config.intermediate_size // config.tensor_parallel_shards
)
self.gate_up_proj = nn.Linear(
in_features=config.text_config.hidden_size,
out_features=2 * self.intermediate_size,
bias=False,
)
self.down_proj = nn.Linear(
self.intermediate_size, config.text_config.hidden_size, bias=False
)
def forward(self, x: Tensor):
concat_x1_x2 = self.gate_up_proj(x)
x1, x2 = op.split(concat_x1_x2, 2, axis=-1)
return self.down_proj(op.gelu(x1, approximate="tanh") * x2)
class Gemma3Attention(nn.Module):
def __init__(self, config: Gemma3Config):
self.head_dim = config.text_config.head_dim
self.num_q_heads = config.text_config.num_attention_heads // config.tensor_parallel_shards
self.num_kv_heads = config.text_config.num_key_value_heads
assert self.num_kv_heads % config.tensor_parallel_shards == 0, (
f"num_kv_heads({self.num_kv_heads}) must be divisible by tensor_parallel_shards"
)
assert self.num_kv_heads >= config.tensor_parallel_shards, (
f"Too large tensor_parallel_shards, must be smaller than {self.num_kv_heads}"
)
self.num_kv_heads = self.num_kv_heads // config.tensor_parallel_shards
self.q_proj = nn.Linear(
in_features=config.text_config.hidden_size,
out_features=self.num_q_heads * self.head_dim,
bias=config.text_config.attention_bias,
)
self.k_proj = nn.Linear(
in_features=config.text_config.hidden_size,
out_features=self.num_kv_heads * self.head_dim,
bias=config.text_config.attention_bias,
)
self.v_proj = nn.Linear(
in_features=config.text_config.hidden_size,
out_features=self.num_kv_heads * self.head_dim,
bias=config.text_config.attention_bias,
)
self.o_proj = nn.Linear(
in_features=self.num_q_heads * self.head_dim,
out_features=config.text_config.hidden_size,
bias=config.text_config.attention_bias,
)
self.q_norm = nn.RMSNorm(
config.text_config.head_dim, -1, config.text_config.rms_norm_eps, bias=False
)
self.k_norm = nn.RMSNorm(
config.text_config.head_dim, -1, config.text_config.rms_norm_eps, bias=False
)
# self.scaling_factor = (self.head_dim / config.text_config.query_pre_attn_scalar) ** 0.5
self.scaling = config.text_config.query_pre_attn_scalar**-0.5
def forward(self, hidden_states: Tensor, paged_kv_cache: PagedKVCache, layer_id: int):
d, h_q = self.head_dim, self.num_q_heads
b, s, _ = hidden_states.shape
# QKV Projection
q_proj = op.reshape(self.q_proj(hidden_states), (b, s, -1, d))
k_proj = op.reshape(self.k_proj(hidden_states), (b, s, -1, d))
v_proj = op.reshape(self.v_proj(hidden_states), (b, s, -1, d))
q_norm = self.q_norm(q_proj)
k_norm = self.k_norm(k_proj)
qkv = op.concat([q_norm, k_norm, v_proj], dim=2)
# Attention
output = op.reshape(
paged_kv_cache.attention_with_fused_qkv(
layer_id, qkv, self.num_q_heads, sm_scale=self.scaling
),
(b, s, h_q * d),
)
return self.o_proj(output)
class Gemma3DecoderLayer(nn.Module):
def __init__(self, config: Gemma3Config):
rms_norm_eps = config.text_config.rms_norm_eps
self.self_attn = Gemma3Attention(config)
self.mlp = Gemma3MLP(config)
# Gemma RMSNorm adds 1 to the weights. It is already fused in the loader
self.input_layernorm = nn.RMSNorm(
config.text_config.hidden_size, -1, rms_norm_eps, bias=False
)
self.post_attention_layernorm = nn.RMSNorm(
config.text_config.hidden_size, -1, rms_norm_eps, bias=False
)
self.pre_feedforward_layernorm = nn.RMSNorm(
config.text_config.hidden_size, -1, rms_norm_eps, bias=False
)
self.post_feedforward_layernorm = nn.RMSNorm(
config.text_config.hidden_size, -1, rms_norm_eps, bias=False
)
def _set_tp():
def _set(layer, hint):
layer.weight.attrs["shard_strategy"] = hint
i = self.mlp.intermediate_size
_set(self.self_attn.q_proj, tp.ShardSingleDim("_shard_q", dim=0))
_set(self.self_attn.k_proj, tp.ShardSingleDim("_shard_k", dim=0))
_set(self.self_attn.v_proj, tp.ShardSingleDim("_shard_v", dim=0))
_set(self.self_attn.q_norm, tp.ShardSingleDim("_shard_q_norm", dim=0))
_set(self.self_attn.k_norm, tp.ShardSingleDim("_shard_k_norm", dim=0))
_set(self.self_attn.o_proj, tp.ShardSingleDim("_shard_o", dim=1))
_set(
self.mlp.gate_up_proj,
tp.ShardSingleDim("_shard_mlp_up", segs=[i, i], dim=0),
)
_set(self.mlp.down_proj, tp.ShardSingleDim("_shard_mlp_down", dim=1))
self.tensor_parallel_shards = config.tensor_parallel_shards
_set_tp()
def forward(self, hidden_states: Tensor, paged_kv_cache: PagedKVCache, layer_id: int):
out = self.self_attn(self.input_layernorm(hidden_states), paged_kv_cache, layer_id)
out = self._apply_post_matmul_norm(out, norm=self.post_attention_layernorm)
hidden_states = out + hidden_states
out = self.pre_feedforward_layernorm(hidden_states)
out = self.mlp(out)
out = self._apply_post_matmul_norm(out, norm=self.post_feedforward_layernorm)
hidden_states = out + hidden_states
return hidden_states
def _apply_post_matmul_norm(self, out: Tensor, norm: nn.Tensor):
if self.tensor_parallel_shards > 1:
return norm(op.ccl_allreduce(out, "sum"))
return norm(out)
class Gemma3TextModel(nn.Module):
def __init__(self, config: Gemma3Config):
self.hidden_size = config.text_config.hidden_size
assert config.text_config.hidden_size % config.text_config.num_attention_heads == 0
self.embed_tokens = GemmaEmbedding("vocab_size", config.text_config.hidden_size)
self.layers = nn.ModuleList(
[Gemma3DecoderLayer(config) for _ in range(config.text_config.num_hidden_layers)]
)
self.norm = nn.RMSNorm(
config.text_config.hidden_size,
-1,
config.text_config.rms_norm_eps,
bias=False,
)
def forward(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
hidden_states = input_embed
hidden_states = hidden_states * (self.hidden_size**0.5)
for layer_id, layer in enumerate(self.layers):
hidden_states = layer(hidden_states, paged_kv_cache, layer_id)
hidden_states = self.norm(hidden_states)
return hidden_states
class Gemma3LanguageModel(nn.Module):
def __init__(self, config: Gemma3Config):
self.model = Gemma3TextModel(config)
self.config = config
self.num_hidden_layers = config.text_config.num_hidden_layers
self.num_attention_heads = config.text_config.num_attention_heads
self.num_key_value_heads = config.text_config.num_key_value_heads
self.head_dim = config.text_config.head_dim
self.hidden_size = config.text_config.hidden_size
self.vocab_size = config.vocab_size
self.rope_theta = config.text_config.position_embedding_base
self.rope_scaling = config.text_config.rope_scaling
self.tensor_parallel_shards = config.tensor_parallel_shards
self.dtype = "float32"
def to(self, dtype: Optional[str] = None):
super().to(dtype=dtype)
if dtype is not None:
self.dtype = dtype
def get_logits(self, hidden_states: Tensor):
logits = self.model.embed_tokens.lm_head_forward(hidden_states)
if logits.dtype != "float32":
logits = logits.astype("float32")
return logits
def batch_forward(
self,
input_embeds: Tensor,
paged_kv_cache: PagedKVCache,
logit_positions: Optional[Tensor] = None,
):
op_ext.configure()
hidden_states = self.model(input_embeds, paged_kv_cache)
if logit_positions is not None:
hidden_states = op.take(hidden_states, logit_positions, axis=1)
logits = self.get_logits(hidden_states)
return logits
def embed(self, input_ids: Tensor):
if self.tensor_parallel_shards > 1:
input_ids = op.ccl_broadcast_from_worker0(input_ids)
return self.model.embed_tokens(input_ids)
def prefill(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.model(input_embed, paged_kv_cache)
hidden_states = index_last_token(hidden_states)
logits = self.get_logits(hidden_states)
return logits, paged_kv_cache
def decode(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.model(input_embed, paged_kv_cache)
logits = self.get_logits(hidden_states)
return logits, paged_kv_cache
def batch_prefill(
self,
input_embeds: Tensor,
logit_positions: Tensor,
paged_kv_cache: PagedKVCache,
):
if self.tensor_parallel_shards > 1:
logit_positions = op.ccl_broadcast_from_worker0(logit_positions)
logits = self.batch_forward(input_embeds, paged_kv_cache, logit_positions)
return logits, paged_kv_cache
def batch_decode(self, input_embeds: Tensor, paged_kv_cache: PagedKVCache):
logits = self.batch_forward(input_embeds, paged_kv_cache)
return logits, paged_kv_cache
def batch_verify(self, input_embeds: Tensor, paged_kv_cache: PagedKVCache):
logits = self.batch_forward(input_embeds, paged_kv_cache)
return logits, paged_kv_cache
def create_paged_kv_cache(
self,
max_batch_size: tirx.Var,
max_total_seq_len: tirx.Var,
prefill_chunk_size: tirx.Var,
page_size: tirx.Var,
support_sliding_window: tirx.Var,
) -> PagedKVCache:
# if "factor" in self.rope_scaling:
# rope_scaling = self.rope_scaling["factor"]
# else:
# rope_scaling = 1
return PagedKVCache.create_generic(
attn_kind=[
(
"mha_sliding"
if ((i + 1) % self.config.text_config.sliding_window_pattern)
else "mha"
)
for i in range(self.num_hidden_layers)
],
max_batch_size=max_batch_size,
max_total_seq_len=max_total_seq_len,
prefill_chunk_size=prefill_chunk_size,
page_size=page_size,
support_sliding_window=support_sliding_window,
num_hidden_layers=self.num_hidden_layers,
num_attention_heads=self.num_attention_heads // self.tensor_parallel_shards,
num_key_value_heads=self.num_key_value_heads // self.tensor_parallel_shards,
qk_head_dim=self.head_dim,
v_head_dim=self.head_dim,
rope_mode=RopeMode.NORMAL,
rope_scale=1,
rope_theta=self.rope_theta,
dtype=self.dtype,
)
def get_default_spec(self):
mod_spec = {
"embed": {
"input_ids": nn.spec.Tensor(["seq_len"], "int32"),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"prefill": {
"input_embed": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"decode": {
"input_embed": nn.spec.Tensor([1, 1, self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_prefill": {
"input_embeds": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"logit_positions": nn.spec.Tensor(["batch_size"], "int32"),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_decode": {
"input_embeds": nn.spec.Tensor(["batch_size", 1, self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_verify": {
"input_embeds": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"create_paged_kv_cache": {
"max_batch_size": int,
"max_total_seq_len": int,
"prefill_chunk_size": int,
"page_size": int,
"support_sliding_window": int,
"$": {
"param_mode": "none",
"effect_mode": "none",
},
},
}
return nn.spec.ModuleSpec.from_raw(mod_spec, self)
class Gemma3ForCausalLM(nn.Module):
def __init__(self, config: Gemma3Config):
super().__init__()
self.config = config
self.language_model = Gemma3LanguageModel(config)
self.vocab_size = config.vocab_size
self.dtype = "float32"
self.tensor_parallel_shards = config.tensor_parallel_shards
def to(self, dtype: Optional[str] = None):
super().to(dtype=dtype)
self.language_model.to(dtype=dtype)
if dtype is not None:
self.dtype = dtype
def get_logits(self, hidden_states: Tensor):
logits = self.language_model.model.embed_tokens.lm_head_forward(hidden_states)
if logits.dtype != "float32":
logits = logits.astype("float32")
return logits
def batch_forward(
self,
input_embeds: Tensor,
paged_kv_cache: PagedKVCache,
logit_positions: Optional[Tensor] = None,
):
op_ext.configure()
hidden_states = self.language_model.model(input_embeds, paged_kv_cache)
if logit_positions is not None:
hidden_states = op.take(hidden_states, logit_positions, axis=1)
logits = self.get_logits(hidden_states)
return logits
def embed(self, input_ids: Tensor):
if self.tensor_parallel_shards > 1:
input_ids = op.ccl_broadcast_from_worker0(input_ids)
return self.language_model.model.embed_tokens(input_ids)
def prefill(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.language_model.model(input_embed, paged_kv_cache)
hidden_states = index_last_token(hidden_states)
logits = self.get_logits(hidden_states)
return logits, paged_kv_cache
def decode(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.language_model.model(input_embed, paged_kv_cache)
logits = self.get_logits(hidden_states)
return logits, paged_kv_cache
def batch_prefill(
self,
input_embeds: Tensor,
logit_positions: Tensor,
paged_kv_cache: PagedKVCache,
):
if self.tensor_parallel_shards > 1:
logit_positions = op.ccl_broadcast_from_worker0(logit_positions)
logits = self.batch_forward(input_embeds, paged_kv_cache, logit_positions)
return logits, paged_kv_cache
def batch_decode(self, input_embeds: Tensor, paged_kv_cache: PagedKVCache):
logits = self.batch_forward(input_embeds, paged_kv_cache)
return logits, paged_kv_cache
def batch_verify(self, input_embeds: Tensor, paged_kv_cache: PagedKVCache):
logits = self.batch_forward(input_embeds, paged_kv_cache)
return logits, paged_kv_cache
def create_paged_kv_cache(
self,
max_batch_size: tirx.Var,
max_total_seq_len: tirx.Var,
prefill_chunk_size: tirx.Var,
page_size: tirx.Var,
support_sliding_window: tirx.Var,
) -> PagedKVCache:
# if "factor" in self.language_model.rope_scaling:
# rope_scaling = self.language_model.rope_scaling["factor"]
# else:
# rope_scaling = 1
return PagedKVCache.create_generic(
attn_kind=[
(
"mha_sliding"
if ((i + 1) % self.config.text_config.sliding_window_pattern)
else "mha"
)
for i in range(self.language_model.num_hidden_layers)
],
max_batch_size=max_batch_size,
max_total_seq_len=max_total_seq_len,
prefill_chunk_size=prefill_chunk_size,
page_size=page_size,
support_sliding_window=support_sliding_window,
num_hidden_layers=self.language_model.num_hidden_layers,
num_attention_heads=self.language_model.num_attention_heads
// self.tensor_parallel_shards,
num_key_value_heads=self.language_model.num_key_value_heads
// self.tensor_parallel_shards,
qk_head_dim=self.language_model.head_dim,
v_head_dim=self.language_model.head_dim,
rope_mode=RopeMode.NORMAL,
rope_scale=1,
rope_theta=self.language_model.rope_theta,
dtype=self.dtype,
)
def get_default_spec(self):
mod_spec = {
"embed": {
"input_ids": nn.spec.Tensor(["seq_len"], "int32"),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"prefill": {
"input_embed": nn.spec.Tensor(
[1, "seq_len", self.language_model.hidden_size], self.dtype
),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"decode": {
"input_embed": nn.spec.Tensor([1, 1, self.language_model.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_prefill": {
"input_embeds": nn.spec.Tensor(
[1, "seq_len", self.language_model.hidden_size], self.dtype
),
"logit_positions": nn.spec.Tensor(["batch_size"], "int32"),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_decode": {
"input_embeds": nn.spec.Tensor(
["batch_size", 1, self.language_model.hidden_size], self.dtype
),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_verify": {
"input_embeds": nn.spec.Tensor(
[1, "seq_len", self.language_model.hidden_size], self.dtype
),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"create_paged_kv_cache": {
"max_batch_size": int,
"max_total_seq_len": int,
"prefill_chunk_size": int,
"page_size": int,
"support_sliding_window": int,
"$": {
"param_mode": "none",
"effect_mode": "none",
},
},
}
return nn.spec.ModuleSpec.from_raw(mod_spec, self)