[Misc] Support FP8 MoE for compressed-tensors (#8588)

tests/weight_loading/models-large.txt

 compressed-tensors, nm-testing/Mixtral-8x7B-Instruct-v0.1-W4A16-quantized, main
 compressed-tensors, nm-testing/Mixtral-8x7B-Instruct-v0.1-W4A16-channel-quantized, main
 compressed-tensors, nm-testing/Mixtral-8x7B-Instruct-v0.1-W8A16-quantized, main
+compressed-tensors, mgoin/DeepSeek-Coder-V2-Lite-Instruct-FP8, main
 gptq_marlin, TheBloke/Mixtral-8x7B-v0.1-GPTQ, main

vllm/model_executor/layers/fused_moe/layer.py

@@ -323,10 +323,12 @@ class FusedMoE(torch.nn.Module):
                       loaded_weight: torch.Tensor, weight_name: str,
                       shard_id: str, expert_id: int) -> None:
 
-        # compressed-tensors represents weights on disk which are flipped
+        # compressed-tensors checkpoints with packed weights are stored flipped
+        # TODO (mgoin): check self.quant_method.quant_config.quant_format
+        # against known CompressionFormat enum values that have this quality
         loaded_weight = loaded_weight.t().contiguous() if (
             self.quant_method.__class__.__name__
-            == "CompressedTensorsMoEMethod") else loaded_weight
+            == "CompressedTensorsWNA16MoEMethod") else loaded_weight
 
         if shard_id not in ("w1", "w2", "w3"):
             raise ValueError(f"shard_id must be ['w1','w2','w3'] but "
@@ -353,6 +355,9 @@ class FusedMoE(torch.nn.Module):
 
         # Case input scale: input_scale loading is only supported for fp8
         if "input_scale" in weight_name:
+            # this is needed for compressed-tensors only
+            loaded_weight = loaded_weight.to(param.data.device)
+
             if param.data[expert_id] != 1 and (param.data[expert_id] -
                                                loaded_weight).abs() > 1e-5:
                 raise ValueError(

vllm/model_executor/layers/quantization/compressed_tensors/compressed_tensors.py

@@ -73,7 +73,7 @@ class CompressedTensorsConfig(QuantizationConfig):
         if isinstance(layer, Attention):
             return CompressedTensorsKVCacheMethod(self)
         if isinstance(layer, FusedMoE):
-            return CompressedTensorsMoEMethod(self)
+            return CompressedTensorsMoEMethod.get_moe_method(self)
         return None
 
     @classmethod

vllm/model_executor/layers/quantization/compressed_tensors/compressed_tensors_moe.py

@@ -5,12 +5,16 @@ from typing import Callable, List, Optional
 import torch
 
 from vllm import _custom_ops as ops
-from vllm.model_executor.layers.fused_moe import FusedMoE, FusedMoEMethodBase
+from vllm.model_executor.layers.fused_moe import (FusedMoE, FusedMoEMethodBase,
+                                                  FusedMoeWeightScaleSupported)
 from vllm.model_executor.layers.quantization.compressed_tensors.schemes import (
     WNA16_SUPPORTED_BITS)
 from vllm.model_executor.layers.quantization.compressed_tensors.utils import (
-    CompressionFormat)
+    CompressionFormat, QuantizationStrategy)
+from vllm.model_executor.layers.quantization.utils.w8a8_utils import (
+    all_close_1d, normalize_e4m3fn_to_e4m3fnuz, per_tensor_dequantize)
 from vllm.model_executor.utils import set_weight_attrs
+from vllm.utils import is_hip, print_warning_once
 
 
 class GPTQMarlinState(Enum):
@@ -18,11 +22,219 @@ class GPTQMarlinState(Enum):
     READY = enum.auto()
 
 
-__all__ = ["CompressedTensorsMoEMethod"]
+__all__ = [
+    "CompressedTensorsMoEMethod", "CompressedTensorsW8A8Fp8MoEMethod",
+    "CompressedTensorsWNA16MoEMethod"
+]
 
 
 class CompressedTensorsMoEMethod(FusedMoEMethodBase):
 
+    @staticmethod
+    def get_moe_method(
+        quant_config: "CompressedTensorsConfig"  # type: ignore # noqa E501
+    ) -> "CompressedTensorsMoEMethod":
+        # TODO: @dsikka: refactor this to use schemes as other kernels
+        # are supported + check if the layer is being ignored.
+        weight_quant = quant_config.target_scheme_map["Linear"].get("weights")
+        input_quant = quant_config.target_scheme_map["Linear"].get(
+            "input_activations")
+
+        if quant_config._is_wNa16_group_channel(weight_quant, input_quant):
+            return CompressedTensorsWNA16MoEMethod(quant_config)
+        elif quant_config._is_fp8_w8a8(weight_quant, input_quant):
+            return CompressedTensorsW8A8Fp8MoEMethod(quant_config)
+        else:
+            raise RuntimeError(
+                f"Unsupported FusedMoe scheme: {weight_quant}, {input_quant}")
+
+
+class CompressedTensorsW8A8Fp8MoEMethod(CompressedTensorsMoEMethod):
+
+    def __init__(
+            self,
+            quant_config: "CompressedTensorsConfig"  # type: ignore # noqa E501
+    ):
+        self.quant_config = quant_config
+        self.weight_quant = self.quant_config.target_scheme_map["Linear"].get(
+            "weights")
+        self.input_quant = self.quant_config.target_scheme_map["Linear"].get(
+            "input_activations")
+
+        if not (self.weight_quant.strategy == QuantizationStrategy.TENSOR
+                and self.input_quant.strategy == QuantizationStrategy.TENSOR):
+            raise ValueError(
+                "For FP8 Fused MoE layers, only per-tensor scales"
+                "for weights and activations are supported. Found "
+                f"{self.weight_quant}, {self.input_quant}")
+
+        self.static_input_scales = not self.input_quant.dynamic
+
+    def create_weights(self, layer: torch.nn.Module, num_experts: int,
+                       hidden_size: int, intermediate_size: int,
+                       params_dtype: torch.dtype, **extra_weight_attrs):
+
+        params_dtype = torch.float8_e4m3fn
+
+        # WEIGHTS
+        w13_weight = torch.nn.Parameter(torch.empty(num_experts,
+                                                    2 * intermediate_size,
+                                                    hidden_size,
+                                                    dtype=params_dtype),
+                                        requires_grad=False)
+        layer.register_parameter("w13_weight", w13_weight)
+        set_weight_attrs(w13_weight, extra_weight_attrs)
+
+        w2_weight = torch.nn.Parameter(torch.empty(num_experts,
+                                                   hidden_size,
+                                                   intermediate_size,
+                                                   dtype=params_dtype),
+                                       requires_grad=False)
+        layer.register_parameter("w2_weight", w2_weight)
+        set_weight_attrs(w2_weight, extra_weight_attrs)
+
+        # WEIGHT_SCALES
+        # Allocate 2 scales for w1 and w3 respectively.
+        # They will be combined to a single scale after weight loading.
+        w13_weight_scale = torch.nn.Parameter(torch.ones(num_experts,
+                                                         2,
+                                                         dtype=torch.float32),
+                                              requires_grad=False)
+        layer.register_parameter("w13_weight_scale", w13_weight_scale)
+
+        w2_weight_scale = torch.nn.Parameter(torch.ones(num_experts,
+                                                        dtype=torch.float32),
+                                             requires_grad=False)
+        layer.register_parameter("w2_weight_scale", w2_weight_scale)
+        # Add the quantization method used (per tensor/grouped/channel)
+        # to ensure the weight scales are loaded in properly
+        extra_weight_attrs.update(
+            {"quant_method": FusedMoeWeightScaleSupported.TENSOR.value})
+        set_weight_attrs(w13_weight_scale, extra_weight_attrs)
+        set_weight_attrs(w2_weight_scale, extra_weight_attrs)
+
+        # INPUT_SCALES
+        if self.static_input_scales:
+            w13_input_scale = torch.nn.Parameter(torch.ones(
+                num_experts, dtype=torch.float32),
+                                                 requires_grad=False)
+            layer.register_parameter("w13_input_scale", w13_input_scale)
+            set_weight_attrs(w13_input_scale, extra_weight_attrs)
+
+            w2_input_scale = torch.nn.Parameter(torch.ones(
+                num_experts, dtype=torch.float32),
+                                                requires_grad=False)
+            layer.register_parameter("w2_input_scale", w2_input_scale)
+            set_weight_attrs(w2_input_scale, extra_weight_attrs)
+        else:
+            layer.w13_input_scale = None
+            layer.w2_input_scale = None
+
+    def process_weights_after_loading(self, layer: torch.nn.Module) -> None:
+        # Fp8 moe kernels require a single activation scale.
+        # We take the max of all the scales in case they differ.
+        if self.static_input_scales:
+            if (layer.w13_input_scale is None or layer.w2_input_scale is None):
+                raise ValueError(
+                    "QuantConfig has static quantization, but found "
+                    "activation scales are None.")
+            if (not all_close_1d(layer.w13_input_scale)
+                    or not all_close_1d(layer.w2_input_scale)):
+                print_warning_once(
+                    "Found input_scales that are not equal for "
+                    "fp8 MoE layer. Using the maximum across experts "
+                    "for each layer. ")
+            layer.w13_input_scale = torch.nn.Parameter(
+                layer.w13_input_scale.max(), requires_grad=False)
+            layer.w2_input_scale = torch.nn.Parameter(
+                layer.w2_input_scale.max(), requires_grad=False)
+
+        # If rocm, normalize the weights and scales to e4m3fnuz
+        if is_hip():
+            # Normalize the weights and scales
+            w13_weight, w13_weight_scale, w13_input_scale = \
+                normalize_e4m3fn_to_e4m3fnuz(
+                    layer.w13_weight, layer.w13_weight_scale,
+                    layer.w13_input_scale)
+            w2_weight, w2_weight_scale, w2_input_scale = \
+                normalize_e4m3fn_to_e4m3fnuz(
+                    layer.w2_weight, layer.w2_weight_scale,
+                    layer.w2_input_scale)
+            # Reset the parameter
+            layer.w13_weight = torch.nn.Parameter(w13_weight,
+                                                  requires_grad=False)
+            layer.w13_weight_scale = torch.nn.Parameter(w13_weight_scale,
+                                                        requires_grad=False)
+            if w13_input_scale is not None:
+                layer.w13_input_scale = torch.nn.Parameter(w13_input_scale,
+                                                           requires_grad=False)
+            layer.w2_weight = torch.nn.Parameter(w2_weight,
+                                                 requires_grad=False)
+            layer.w2_weight_scale = torch.nn.Parameter(w2_weight_scale,
+                                                       requires_grad=False)
+            if w2_input_scale is not None:
+                layer.w2_input_scale = torch.nn.Parameter(w2_input_scale,
+                                                          requires_grad=False)
+
+        # Fp8 moe kernel needs single weight scale for w13 per expert.
+        # We take the max then dequant and requant each expert.
+        assert layer.w13_weight_scale is not None
+        shard_size = layer.intermediate_size_per_partition
+        max_w13_scales = layer.w13_weight_scale.max(dim=1).values
+        for expert_id in range(layer.num_experts):
+            start = 0
+            for shard_id in range(2):
+                dq_weight = per_tensor_dequantize(
+                    layer.w13_weight[expert_id][start:start + shard_size, :],
+                    layer.w13_weight_scale[expert_id][shard_id])
+                layer.w13_weight[expert_id][
+                    start:start + shard_size, :], _ = ops.scaled_fp8_quant(
+                        dq_weight, max_w13_scales[expert_id])
+                start += shard_size
+
+        layer.w13_weight_scale = torch.nn.Parameter(max_w13_scales,
+                                                    requires_grad=False)
+
+    def apply(
+        self,
+        layer: torch.nn.Module,
+        x: torch.Tensor,
+        router_logits: torch.Tensor,
+        top_k: int,
+        renormalize: bool = True,
+        use_grouped_topk: bool = False,
+        num_expert_group: Optional[int] = None,
+        topk_group: Optional[int] = None,
+        custom_routing_function: Optional[Callable] = None,
+    ) -> torch.Tensor:
+
+        from vllm.model_executor.layers.fused_moe import fused_experts
+
+        topk_weights, topk_ids = FusedMoE.select_experts(
+            hidden_states=x,
+            router_logits=router_logits,
+            use_grouped_topk=use_grouped_topk,
+            top_k=top_k,
+            renormalize=renormalize,
+            topk_group=topk_group,
+            num_expert_group=num_expert_group,
+            custom_routing_function=custom_routing_function)
+
+        return fused_experts(x,
+                             layer.w13_weight,
+                             layer.w2_weight,
+                             topk_weights=topk_weights,
+                             topk_ids=topk_ids,
+                             inplace=True,
+                             use_fp8_w8a8=True,
+                             w1_scale=layer.w13_weight_scale,
+                             w2_scale=layer.w2_weight_scale,
+                             a1_scale=layer.w13_input_scale,
+                             a2_scale=layer.w2_input_scale)
+
+
+class CompressedTensorsWNA16MoEMethod(CompressedTensorsMoEMethod):
+
     def __init__(
             self,
             quant_config: "CompressedTensorsConfig"  # type: ignore # noqa E501

vllm/model_executor/models/phimoe.py

@@ -321,13 +321,13 @@ class PhiMoEAttention(nn.Module):
             self.total_num_heads,
             self.total_num_kv_heads,
             bias=True,
-            quant_config=None,
+            quant_config=quant_config,
         )
         self.o_proj = RowParallelLinear(
             self.total_num_heads * self.head_dim,
             hidden_size,
             bias=True,
-            quant_config=None,
+            quant_config=quant_config,
         )
         self.rotary_emb = get_rope(
             self.head_dim,