[Model] Add Afmoe architecture implementation (#28332)

Signed-off-by: Maziyar Panahi <maziyar.panahi@iscpif.fr>
Signed-off-by: Pranav <veldurthipranav@gmail.com>
Co-authored-by: Maziyar Panahi <maziyar.panahi@iscpif.fr>

docs/models/supported_models.md

@@ -351,6 +351,7 @@ th {
 
 | Architecture | Models | Example HF Models | [LoRA](../features/lora.md) | [PP](../serving/parallelism_scaling.md) |
 |--------------|--------|-------------------|----------------------|---------------------------|
+| `AfmoeForCausalLM` | Afmoe | TBA | ✅︎ | ✅︎ |
 | `ApertusForCausalLM` | Apertus | `swiss-ai/Apertus-8B-2509`, `swiss-ai/Apertus-70B-Instruct-2509`, etc. | ✅︎ | ✅︎ |
 | `AquilaForCausalLM` | Aquila, Aquila2 | `BAAI/Aquila-7B`, `BAAI/AquilaChat-7B`, etc. | ✅︎ | ✅︎ |
 | `ArceeForCausalLM` | Arcee (AFM) | `arcee-ai/AFM-4.5B-Base`, etc. | ✅︎ | ✅︎ |

tests/models/registry.py

@@ -173,6 +173,10 @@ class _HfExamplesInfo:
 
 _TEXT_GENERATION_EXAMPLE_MODELS = {
     # [Decoder-only]
+    "AfmoeForCausalLM": _HfExamplesInfo(
+        "arcee-ai/Trinity-Nano",
+        is_available_online=False,
+    ),
     "ApertusForCausalLM": _HfExamplesInfo("swiss-ai/Apertus-8B-Instruct-2509"),
     "AquilaModel": _HfExamplesInfo("BAAI/AquilaChat-7B", trust_remote_code=True),
     "AquilaForCausalLM": _HfExamplesInfo("BAAI/AquilaChat2-7B", trust_remote_code=True),

vllm/model_executor/models/afmoe.py

@@ -0,0 +1,711 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+"""Inference-only AfMoE model compatible with HuggingFace weights."""
+
+import typing
+from collections.abc import Callable, Iterable
+from itertools import islice
+from typing import Any
+
+import torch
+from torch import nn
+
+from vllm.attention import Attention, AttentionType
+from vllm.compilation.decorators import support_torch_compile
+from vllm.config import CacheConfig, VllmConfig, get_current_vllm_config
+from vllm.distributed import (
+    get_ep_group,
+    get_pp_group,
+    get_tensor_model_parallel_world_size,
+)
+from vllm.logger import init_logger
+from vllm.model_executor.layers.fused_moe.shared_fused_moe import SharedFusedMoE
+from vllm.model_executor.layers.layernorm import RMSNorm
+from vllm.model_executor.layers.linear import (
+    ColumnParallelLinear,
+    QKVParallelLinear,
+    RowParallelLinear,
+)
+from vllm.model_executor.layers.logits_processor import LogitsProcessor
+from vllm.model_executor.layers.quantization import QuantizationConfig
+from vllm.model_executor.layers.rotary_embedding import get_rope
+from vllm.model_executor.layers.vocab_parallel_embedding import (
+    ParallelLMHead,
+    VocabParallelEmbedding,
+)
+from vllm.model_executor.model_loader.weight_utils import (
+    default_weight_loader,
+    maybe_remap_kv_scale_name,
+)
+from vllm.model_executor.models.interfaces import SupportsLoRA, SupportsPP
+from vllm.model_executor.models.llama import LlamaMLP as AfmoeMLP
+from vllm.model_executor.models.utils import (
+    AutoWeightsLoader,
+    PPMissingLayer,
+    WeightsMapper,
+    extract_layer_index,
+    is_pp_missing_parameter,
+    make_empty_intermediate_tensors_factory,
+    make_layers,
+    maybe_prefix,
+)
+from vllm.sequence import IntermediateTensors
+
+logger = init_logger(__name__)
+
+
+class AfmoeMoE(nn.Module):
+    def __init__(
+        self,
+        config,  # AfmoeConfig
+        quant_config: QuantizationConfig | None = None,
+        prefix: str = "",
+        enable_eplb: bool = False,
+    ):
+        super().__init__()
+        self.tp_size = get_tensor_model_parallel_world_size()
+        self.route_scale = config.route_scale
+        self.score_func = config.score_func
+        self.route_norm = config.route_norm
+
+        self.ep_group = get_ep_group().device_group
+        self.ep_rank = self.ep_group.rank()
+        self.ep_size = self.ep_group.size()
+        self.n_routed_experts: int = config.num_experts
+        self.n_shared_experts: int = config.num_shared_experts
+
+        if config.hidden_act != "silu":
+            raise ValueError(
+                f"Unsupported activation: {config.hidden_act}. "
+                "Only silu is supported for now."
+            )
+
+        # Router gate
+        self.gate = nn.Linear(
+            config.hidden_size,
+            config.num_experts,
+            bias=False,
+            dtype=torch.float32,
+        )
+        self.expert_bias = nn.Parameter(
+            torch.empty(config.num_experts, dtype=torch.float32)
+        )
+
+        # Load balancing settings
+        vllm_config = get_current_vllm_config()
+        eplb_config = vllm_config.parallel_config.eplb_config
+        self.enable_eplb = enable_eplb
+
+        self.n_redundant_experts = eplb_config.num_redundant_experts
+        self.n_logical_experts = self.n_routed_experts
+        self.n_physical_experts = self.n_logical_experts + self.n_redundant_experts
+        self.n_local_physical_experts = self.n_physical_experts // self.ep_size
+
+        self.physical_expert_start = self.ep_rank * self.n_local_physical_experts
+        self.physical_expert_end = (
+            self.physical_expert_start + self.n_local_physical_experts
+        )
+
+        self.shared_experts = None
+        # Shared experts
+        if config.num_shared_experts > 0:
+            intermediate_size = config.moe_intermediate_size * config.num_shared_experts
+            self.shared_experts = AfmoeMLP(
+                hidden_size=config.hidden_size,
+                intermediate_size=intermediate_size,
+                hidden_act=config.hidden_act,
+                quant_config=quant_config,
+                reduce_results=False,
+                prefix=f"{prefix}.shared_experts",
+            )
+
+        # Routed experts using SharedFusedMoE
+        self.experts = SharedFusedMoE(
+            shared_experts=self.shared_experts,
+            num_experts=config.num_experts,
+            top_k=config.num_experts_per_tok,
+            hidden_size=config.hidden_size,
+            intermediate_size=config.moe_intermediate_size,
+            reduce_results=False,
+            renormalize=self.route_norm if self.score_func == "sigmoid" else False,
+            quant_config=quant_config,
+            use_grouped_topk=True,
+            num_expert_group=config.n_group,
+            topk_group=config.topk_group,
+            prefix=f"{prefix}.experts",
+            scoring_func=self.score_func,
+            routed_scaling_factor=self.route_scale,
+            e_score_correction_bias=self.expert_bias,
+            enable_eplb=self.enable_eplb,
+            num_redundant_experts=self.n_redundant_experts,
+        )
+
+    def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
+        num_tokens, hidden_dim = hidden_states.shape
+        hidden_states = hidden_states.view(-1, hidden_dim)
+
+        router_logits = self.gate(hidden_states.to(dtype=torch.float32))
+
+        fused_moe_out = self.experts(
+            hidden_states=hidden_states, router_logits=router_logits
+        )
+
+        if self.shared_experts is not None:
+            shared_output, final_hidden_states = fused_moe_out
+            final_hidden_states = final_hidden_states + shared_output
+        else:
+            final_hidden_states = fused_moe_out
+        if self.tp_size > 1:
+            final_hidden_states = self.experts.maybe_all_reduce_tensor_model_parallel(
+                final_hidden_states
+            )
+
+        return final_hidden_states.view(num_tokens, hidden_dim)
+
+
+class AfmoeAttention(nn.Module):
+    def __init__(
+        self,
+        config,  # AfmoeConfig
+        layer_idx: int,
+        hidden_size: int,
+        num_heads: int,
+        num_kv_heads: int,
+        rope_theta: float = 10000,
+        rope_scaling: dict[str, Any] | None = None,
+        max_position_embeddings: int = 131072,
+        head_dim: int | None = None,
+        rms_norm_eps: float = 1e-05,
+        cache_config: CacheConfig | None = None,
+        quant_config: QuantizationConfig | None = None,
+        prefix: str = "",
+        attn_type: str = AttentionType.DECODER,
+    ) -> None:
+        super().__init__()
+        self.layer_idx = layer_idx
+        self.hidden_size = hidden_size
+        tp_size = get_tensor_model_parallel_world_size()
+        self.total_num_heads = num_heads
+        assert self.total_num_heads % tp_size == 0
+        self.num_heads = self.total_num_heads // tp_size
+        self.total_num_kv_heads = num_kv_heads
+        if self.total_num_kv_heads >= tp_size:
+            # Number of KV heads is greater than TP size, so we partition
+            # the KV heads across multiple tensor parallel GPUs.
+            assert self.total_num_kv_heads % tp_size == 0
+        else:
+            # Number of KV heads is less than TP size, so we replicate
+            # the KV heads across multiple tensor parallel GPUs.
+            assert tp_size % self.total_num_kv_heads == 0
+        self.num_kv_heads = max(1, self.total_num_kv_heads // tp_size)
+        self.head_dim = head_dim or (hidden_size // self.total_num_heads)
+        self.q_size = self.num_heads * self.head_dim
+        self.kv_size = self.num_kv_heads * self.head_dim
+        self.scaling = self.head_dim**-0.5
+        self.rope_theta = rope_theta
+        self.max_position_embeddings = max_position_embeddings
+
+        # Check if this is a local attention layer
+        self.is_local_attention = config.layer_types[layer_idx] == "sliding_attention"
+        self.sliding_window = config.sliding_window if self.is_local_attention else None
+
+        self.qkv_proj = QKVParallelLinear(
+            self.hidden_size,
+            self.head_dim,
+            self.total_num_heads,
+            self.total_num_kv_heads,
+            bias=False,
+            quant_config=quant_config,
+            prefix=f"{prefix}.qkv_proj",
+        )
+
+        self.o_proj = RowParallelLinear(
+            self.total_num_heads * self.head_dim,
+            self.hidden_size,
+            bias=False,
+            quant_config=quant_config,
+            prefix=f"{prefix}.o_proj",
+        )
+
+        # Gating projection
+        self.gate_proj = ColumnParallelLinear(
+            hidden_size,
+            self.total_num_heads * self.head_dim,
+            bias=False,
+            quant_config=quant_config,
+            prefix=f"{prefix}.gate_proj",
+        )
+
+        # Q/K normalization
+        self.q_norm = RMSNorm(self.head_dim, eps=config.rms_norm_eps)
+        self.k_norm = RMSNorm(self.head_dim, eps=config.rms_norm_eps)
+
+        # Only create rotary embeddings for local attention
+        if self.is_local_attention:
+            self.rotary_emb = get_rope(
+                self.head_dim,
+                rotary_dim=self.head_dim,
+                max_position=max_position_embeddings,
+                base=rope_theta,
+                rope_scaling=rope_scaling,
+                is_neox_style=True,
+            )
+        else:
+            self.rotary_emb = None
+
+        self.attn = Attention(
+            self.num_heads,
+            self.head_dim,
+            self.scaling,
+            num_kv_heads=self.num_kv_heads,
+            cache_config=cache_config,
+            quant_config=quant_config,
+            per_layer_sliding_window=self.sliding_window,
+            prefix=f"{prefix}.attn",
+            attn_type=attn_type,
+        )
+
+    def forward(
+        self,
+        positions: torch.Tensor,
+        hidden_states: torch.Tensor,
+    ) -> torch.Tensor:
+        qkv, _ = self.qkv_proj(hidden_states)
+        gate, _ = self.gate_proj(hidden_states)
+        q, k, v = qkv.split([self.q_size, self.kv_size, self.kv_size], dim=-1)
+
+        # Apply Q/K normalization
+        q = self.q_norm(q.reshape(-1, self.num_heads, self.head_dim)).reshape(q.shape)
+        k = self.k_norm(k.reshape(-1, self.num_kv_heads, self.head_dim)).reshape(
+            k.shape
+        )
+
+        # Apply rotary embeddings only for local attention
+        if self.is_local_attention and self.rotary_emb is not None:
+            q, k = self.rotary_emb(positions, q, k)
+
+        attn_output = self.attn(q, k, v)
+
+        # Apply gating
+        attn_output = attn_output * torch.sigmoid(gate)
+        output, _ = self.o_proj(attn_output)
+        return output
+
+
+class AfmoeDecoderLayer(nn.Module):
+    def __init__(
+        self,
+        config,  # AfmoeConfig
+        cache_config: CacheConfig | None = None,
+        quant_config: QuantizationConfig | None = None,
+        prefix: str = "",
+        enable_eplb: bool = False,
+    ) -> None:
+        super().__init__()
+        self.hidden_size = config.hidden_size
+        rope_theta = getattr(config, "rope_theta", 10000)
+        rope_scaling = getattr(config, "rope_scaling", None)
+        if rope_scaling is not None and getattr(
+            config, "original_max_position_embeddings", None
+        ):
+            rope_scaling["original_max_position_embeddings"] = (
+                config.original_max_position_embeddings
+            )
+        max_position_embeddings = getattr(config, "max_position_embeddings", 131072)
+
+        # DecoderLayers are created with `make_layers` which passes the prefix
+        # with the layer's index.
+        self.layer_idx = extract_layer_index(prefix)
+
+        self.self_attn = AfmoeAttention(
+            config=config,
+            layer_idx=self.layer_idx,
+            hidden_size=self.hidden_size,
+            num_heads=config.num_attention_heads,
+            num_kv_heads=config.num_key_value_heads,
+            rope_theta=rope_theta,
+            rope_scaling=rope_scaling,
+            max_position_embeddings=max_position_embeddings,
+            head_dim=config.head_dim,
+            rms_norm_eps=config.rms_norm_eps,
+            cache_config=cache_config,
+            quant_config=quant_config,
+            prefix=f"{prefix}.self_attn",
+        )
+
+        # MoE or dense FFN
+        self.moe_enabled = self.layer_idx >= config.num_dense_layers
+        if self.moe_enabled:
+            self.mlp = AfmoeMoE(
+                config=config,
+                quant_config=quant_config,
+                prefix=f"{prefix}.mlp",
+                enable_eplb=enable_eplb,
+            )
+        else:
+            self.mlp = AfmoeMLP(
+                hidden_size=config.hidden_size,
+                intermediate_size=config.intermediate_size,
+                hidden_act=config.hidden_act,
+                quant_config=quant_config,
+                prefix=f"{prefix}.mlp",
+            )
+
+        self.input_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
+        self.post_attention_layernorm = RMSNorm(
+            config.hidden_size, eps=config.rms_norm_eps
+        )
+        self.pre_mlp_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
+        self.post_mlp_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
+
+    def forward(
+        self,
+        positions: torch.Tensor,
+        hidden_states: torch.Tensor,
+        residual: torch.Tensor | None,
+    ) -> tuple[torch.Tensor, torch.Tensor]:
+        if residual is None:
+            residual = hidden_states
+            hidden_states = self.input_layernorm(hidden_states)
+        else:
+            hidden_states, residual = self.input_layernorm(hidden_states, residual)
+
+        hidden_states = self.self_attn(
+            positions=positions,
+            hidden_states=hidden_states,
+        )
+        hidden_states = self.post_attention_layernorm(hidden_states)  # attn norm b
+
+        # Fully Connected
+        hidden_states, residual = self.pre_mlp_layernorm(  # ffn norm a
+            hidden_states, residual
+        )
+        hidden_states = self.mlp(hidden_states)
+        hidden_states = self.post_mlp_layernorm(hidden_states)  # ffn norm b
+
+        return hidden_states, residual
+
+
+@support_torch_compile(
+    dynamic_arg_dims={
+        "input_ids": 0,
+        "positions": -1,
+        "intermediate_tensors": 0,
+        "inputs_embeds": 0,
+    }
+)
+class AfmoeModel(nn.Module):
+    def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
+        super().__init__()
+
+        config = vllm_config.model_config.hf_config
+        cache_config = vllm_config.cache_config
+        quant_config = vllm_config.quant_config
+        enable_eplb = vllm_config.parallel_config.enable_eplb
+        self.config = config
+
+        self.vocab_size = config.vocab_size
+        self.mup_enabled = config.mup_enabled
+
+        if get_pp_group().is_first_rank:
+            self.embed_tokens = VocabParallelEmbedding(
+                config.vocab_size, config.hidden_size, prefix=f"{prefix}.embed_tokens"
+            )
+        else:
+            self.embed_tokens = PPMissingLayer()
+
+        self.start_layer, self.end_layer, self.layers = make_layers(
+            config.num_hidden_layers,
+            lambda prefix: AfmoeDecoderLayer(
+                config=config,
+                cache_config=cache_config,
+                quant_config=quant_config,
+                prefix=prefix,
+                enable_eplb=enable_eplb,
+            ),
+            prefix=f"{prefix}.layers",
+        )
+
+        if get_pp_group().is_last_rank:
+            self.norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
+        else:
+            self.norm = PPMissingLayer()
+
+        self.make_empty_intermediate_tensors = make_empty_intermediate_tensors_factory(
+            ["hidden_states", "residual"], config.hidden_size
+        )
+
+    def embed_input_ids(self, input_ids: torch.Tensor) -> torch.Tensor:
+        return self.embed_tokens(input_ids)
+
+    def forward(
+        self,
+        input_ids: torch.Tensor,
+        positions: torch.Tensor,
+        intermediate_tensors: IntermediateTensors | None = None,
+        inputs_embeds: torch.Tensor | None = None,
+    ) -> torch.Tensor | IntermediateTensors:
+        if get_pp_group().is_first_rank:
+            if inputs_embeds is not None:
+                hidden_states = inputs_embeds
+            else:
+                hidden_states = self.embed_input_ids(input_ids)
+
+            # Apply muP input scaling if enabled
+            if self.mup_enabled:
+                hidden_states = hidden_states * (self.config.hidden_size**0.5)
+
+            residual = None
+        else:
+            assert intermediate_tensors is not None
+            hidden_states = intermediate_tensors["hidden_states"]
+            residual = intermediate_tensors["residual"]
+
+        for layer in islice(self.layers, self.start_layer, self.end_layer):
+            hidden_states, residual = layer(positions, hidden_states, residual)
+
+        if not get_pp_group().is_last_rank:
+            return IntermediateTensors(
+                {"hidden_states": hidden_states, "residual": residual}
+            )
+
+        hidden_states, _ = self.norm(hidden_states, residual)
+        return hidden_states
+
+    def make_empty_intermediate_tensors(
+        self, batch_size: int, dtype: torch.dtype, device: torch.device
+    ) -> IntermediateTensors:
+        return IntermediateTensors(
+            {
+                "hidden_states": torch.zeros(
+                    (batch_size, self.config.hidden_size), dtype=dtype, device=device
+                ),
+                "residual": torch.zeros(
+                    (batch_size, self.config.hidden_size), dtype=dtype, device=device
+                ),
+            }
+        )
+
+    def get_expert_mapping(self) -> list[tuple[str, str, int, str]]:
+        # Params for weights, fp8 weight scales, fp8 activation scales
+        # (param_name, weight_name, expert_id, shard_id)
+        return SharedFusedMoE.make_expert_params_mapping(
+            ckpt_gate_proj_name="gate_proj",
+            ckpt_down_proj_name="down_proj",
+            ckpt_up_proj_name="up_proj",
+            num_experts=self.config.num_experts,
+        )
+
+    def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]) -> set[str]:
+        stacked_params_mapping = [
+            # (param_name, shard_name, shard_id)
+            ("qkv_proj", "q_proj", "q"),
+            ("qkv_proj", "k_proj", "k"),
+            ("qkv_proj", "v_proj", "v"),
+            ("gate_up_proj", "gate_proj", 0),
+            ("gate_up_proj", "up_proj", 1),
+        ]
+
+        params_dict = dict(self.named_parameters())
+        loaded_params: set[str] = set()
+        expert_params_mapping = self.get_expert_mapping()
+
+        for name, loaded_weight in weights:
+            for param_name, weight_name, shard_id in stacked_params_mapping:
+                # Skip non-stacked layers and experts (experts handled below).
+                if (weight_name not in name) or ("self_attn.gate_proj" in name):
+                    continue
+                # We have mlp.experts[0].gate_proj in the checkpoint.
+                # Since we handle the experts below in expert_params_mapping,
+                # we need to skip here BEFORE we update the name, otherwise
+                # name will be updated to mlp.experts[0].gate_up_proj, which
+                # will then be updated below in expert_params_mapping
+                # for mlp.experts[0].gate_gate_up_proj, which breaks load.
+                if ("mlp.experts." in name) and name not in params_dict:
+                    continue
+
+                name = name.replace(weight_name, param_name)
+                # Skip loading extra bias for GPTQ models.
+                if name.endswith(".bias") and name not in params_dict:
+                    continue
+                if is_pp_missing_parameter(name, self):
+                    continue
+
+                param = params_dict[name]
+                weight_loader = param.weight_loader
+                weight_loader(param, loaded_weight, shard_id)
+                break
+            else:
+                is_expert_weight = False
+                for mapping in expert_params_mapping:
+                    param_name, weight_name, expert_id, shard_id = mapping
+                    if weight_name not in name:
+                        continue
+
+                    # Anyway, this is an expert weight and should not be
+                    # attempted to load as other weights later
+                    is_expert_weight = True
+
+                    # Do not modify `name` since the loop may continue here
+                    # Instead, create a new variable
+                    name_mapped = name.replace(weight_name, param_name)
+
+                    if is_pp_missing_parameter(name_mapped, self):
+                        continue
+
+                    param = params_dict[name_mapped]
+                    # We should ask the weight loader to return success or not
+                    # here since otherwise we may skip experts with other
+                    # available replicas.
+                    weight_loader = typing.cast(
+                        Callable[..., bool], param.weight_loader
+                    )
+                    success = weight_loader(
+                        param,
+                        loaded_weight,
+                        name_mapped,
+                        shard_id=shard_id,
+                        expert_id=expert_id,
+                        return_success=True,
+                    )
+                    if success:
+                        name = name_mapped
+                        break
+                else:
+                    if is_expert_weight:
+                        # We've checked that this is an expert weight
+                        # However it's not mapped locally to this rank
+                        # So we simply skip it
+                        continue
+
+                    # Skip loading extra bias for GPTQ models.
+                    if name.endswith(".bias") and name not in params_dict:
+                        continue
+
+                    # Remapping the name of FP8 kv-scale.
+                    name = maybe_remap_kv_scale_name(name, params_dict)
+                    if name is None:
+                        continue
+
+                    if is_pp_missing_parameter(name, self):
+                        continue
+
+                    param = params_dict[name]
+                    weight_loader = getattr(
+                        param, "weight_loader", default_weight_loader
+                    )
+                    weight_loader(param, loaded_weight)
+            loaded_params.add(name)
+
+        return loaded_params
+
+
+class AfmoeForCausalLM(nn.Module, SupportsPP, SupportsLoRA):
+    packed_modules_mapping = {
+        "qkv_proj": [
+            "q_proj",
+            "k_proj",
+            "v_proj",
+        ],
+        "gate_up_proj": [
+            "gate_proj",
+            "up_proj",
+        ],
+    }
+
+    hf_to_vllm_mapper = WeightsMapper(
+        orig_to_new_suffix={
+            ".router.gate.weight": ".gate.weight",
+        },
+    )
+
+    fall_back_to_pt_during_load = False
+
+    def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
+        super().__init__()
+        config = vllm_config.model_config.hf_config
+        quant_config = vllm_config.quant_config
+        self.config = config
+        self.quant_config = quant_config
+        self.model = AfmoeModel(
+            vllm_config=vllm_config, prefix=maybe_prefix(prefix, "model")
+        )
+        if get_pp_group().is_last_rank:
+            self.lm_head = ParallelLMHead(
+                config.vocab_size, config.hidden_size, quant_config=quant_config
+            )
+        else:
+            self.lm_head = PPMissingLayer()
+        self.logits_processor = LogitsProcessor(config.vocab_size)
+        self.make_empty_intermediate_tensors = (
+            self.model.make_empty_intermediate_tensors
+        )
+        self.expert_weights = []
+
+        # Set MoE hyperparameters
+        self.num_moe_layers = config.num_hidden_layers - config.num_dense_layers
+        self.num_expert_groups = config.n_group
+
+        self.moe_layers: list[SharedFusedMoE] = []
+        example_moe = None
+        for layer in self.model.layers:
+            if isinstance(layer, PPMissingLayer):
+                continue
+
+            assert isinstance(layer, AfmoeDecoderLayer)
+            if layer.moe_enabled:
+                example_moe = layer.mlp
+                self.moe_layers.append(layer.mlp.experts)
+
+        if example_moe is None and self.num_moe_layers > 0:
+            raise RuntimeError("No AfmoeMoE layer found in model.layers.")
+
+        if example_moe is not None:
+            self.num_logical_experts = example_moe.n_logical_experts
+            self.num_physical_experts = example_moe.n_physical_experts
+            self.num_local_physical_experts = example_moe.n_local_physical_experts
+            self.num_routed_experts = example_moe.n_routed_experts
+            self.num_shared_experts = example_moe.n_shared_experts
+            self.num_redundant_experts = example_moe.n_redundant_experts
+
+    def set_eplb_state(
+        self,
+        expert_load_view: torch.Tensor,
+        logical_to_physical_map: torch.Tensor,
+        logical_replica_count: torch.Tensor,
+    ) -> None:
+        for layer_idx, layer in enumerate(self.moe_layers):
+            # Register the expert weights.
+            self.expert_weights.append(layer.get_expert_weights())
+            layer.set_eplb_state(
+                moe_layer_idx=layer_idx,
+                expert_load_view=expert_load_view,
+                logical_to_physical_map=logical_to_physical_map,
+                logical_replica_count=logical_replica_count,
+            )
+
+    def embed_input_ids(self, input_ids: torch.Tensor) -> torch.Tensor:
+        return self.model.embed_input_ids(input_ids)
+
+    def forward(
+        self,
+        input_ids: torch.Tensor,
+        positions: torch.Tensor,
+        intermediate_tensors: IntermediateTensors | None = None,
+        inputs_embeds: torch.Tensor | None = None,
+    ) -> torch.Tensor | IntermediateTensors:
+        hidden_states = self.model(
+            input_ids, positions, intermediate_tensors, inputs_embeds
+        )
+        return hidden_states
+
+    def compute_logits(self, hidden_states: torch.Tensor) -> torch.Tensor | None:
+        logits = self.logits_processor(self.lm_head, hidden_states)
+        return logits
+
+    def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]) -> set[str]:
+        loader = AutoWeightsLoader(self)
+        return loader.load_weights(weights, mapper=self.hf_to_vllm_mapper)
+
+    def get_expert_mapping(self) -> list[tuple[str, str, int, str]]:
+        return self.model.get_expert_mapping()

vllm/model_executor/models/registry.py

@@ -56,6 +56,7 @@ logger = init_logger(__name__)
 
 _TEXT_GENERATION_MODELS = {
     # [Decoder-only]
+    "AfmoeForCausalLM": ("afmoe", "AfmoeForCausalLM"),
     "ApertusForCausalLM": ("apertus", "ApertusForCausalLM"),
     "AquilaModel": ("llama", "LlamaForCausalLM"),
     "AquilaForCausalLM": ("llama", "LlamaForCausalLM"),  # AquilaChat2

vllm/transformers_utils/config.py

@@ -77,6 +77,7 @@ class LazyConfigDict(dict):
 
 
 _CONFIG_REGISTRY: dict[str, type[PretrainedConfig]] = LazyConfigDict(
+    afmoe="AfmoeConfig",
     chatglm="ChatGLMConfig",
     deepseek_vl_v2="DeepseekVLV2Config",
     deepseek_v32=DeepseekV3Config,

vllm/transformers_utils/configs/__init__.py

@@ -7,6 +7,7 @@ Model configs may be defined in this directory for the following reasons:
 - There is a need to override the existing config to support vLLM.
 """
 
+from vllm.transformers_utils.configs.afmoe import AfmoeConfig
 from vllm.transformers_utils.configs.chatglm import ChatGLMConfig
 from vllm.transformers_utils.configs.deepseek_vl2 import DeepseekVLV2Config
 from vllm.transformers_utils.configs.dotsocr import DotsOCRConfig
@@ -40,6 +41,7 @@ from vllm.transformers_utils.configs.step3_vl import (
 from vllm.transformers_utils.configs.ultravox import UltravoxConfig
 
 __all__ = [
+    "AfmoeConfig",
     "ChatGLMConfig",
     "DeepseekVLV2Config",
     "DotsOCRConfig",

vllm/transformers_utils/configs/afmoe.py

@@ -0,0 +1,84 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from transformers.configuration_utils import PretrainedConfig
+
+
+class AfmoeConfig(PretrainedConfig):
+    model_type = "afmoe"
+
+    def __init__(
+        self,
+        vocab_size: int = 200_192,
+        hidden_size: int = 2048,
+        intermediate_size: int = 6144,
+        moe_intermediate_size: int = 1408,
+        num_hidden_layers: int = 32,
+        num_dense_layers: int = 1,
+        num_attention_heads: int = 16,
+        num_key_value_heads: int | None = None,
+        head_dim: int = 128,
+        hidden_act: str = "silu",
+        max_position_embeddings: int = 131072,
+        initializer_range: float = 0.02,
+        rms_norm_eps: float = 1e-5,
+        use_cache: bool = True,
+        tie_word_embeddings: bool = False,
+        rope_theta: float = 10000.0,
+        rope_scaling: dict | None = None,
+        num_experts: int = 64,
+        num_experts_per_tok: int = 6,
+        num_shared_experts: int = 2,
+        num_expert_groups: int = 1,
+        num_limited_groups: int = 1,
+        score_func: str = "sigmoid",
+        route_norm: bool = True,
+        route_scale: float = 1.0,
+        global_attn_every_n_layers: int = 4,
+        sliding_window: int = 2048,
+        layer_types: list[str] | None = None,
+        attention_dropout: float = 0.0,
+        mup_enabled: bool = False,
+        n_group: int = 1,
+        topk_group: int = 1,
+        **kwargs,
+    ):
+        self.vocab_size = vocab_size
+        self.hidden_size = hidden_size
+        self.intermediate_size = intermediate_size
+        self.num_hidden_layers = num_hidden_layers
+        self.num_dense_layers = num_dense_layers
+        self.num_attention_heads = num_attention_heads
+        self.num_key_value_heads = num_key_value_heads or num_attention_heads
+        self.head_dim = head_dim
+        self.hidden_act = hidden_act
+        self.max_position_embeddings = max_position_embeddings
+        self.initializer_range = initializer_range
+        self.rms_norm_eps = rms_norm_eps
+        self.use_cache = use_cache
+        self.rope_theta = rope_theta
+        self.rope_scaling = rope_scaling
+
+        self.moe_intermediate_size = moe_intermediate_size
+        self.num_experts = num_experts
+        self.num_experts_per_tok = num_experts_per_tok
+        self.num_shared_experts = num_shared_experts
+        self.num_expert_groups = num_expert_groups
+        self.num_limited_groups = num_limited_groups
+        self.score_func = score_func
+        self.route_norm = route_norm
+        self.route_scale = route_scale
+
+        self.global_attn_every_n_layers = global_attn_every_n_layers
+        self.sliding_window = sliding_window
+        self.layer_types = layer_types
+        self.attention_dropout = attention_dropout
+
+        self.mup_enabled = mup_enabled
+        self.n_group = n_group
+        self.topk_group = topk_group
+
+        super().__init__(tie_word_embeddings=tie_word_embeddings, **kwargs)
+
+
+__all__ = ["AfmoeConfig"]