[xpu]support moe models on XPU platform

vllm/model_executor/layers/fused_moe/layer.py

@@ -327,7 +327,14 @@ def process_weights_after_loading(self, layer: torch.nn.Module) -> None:
             layer.w13_weight.data = shuffled_w13
             layer.w2_weight.data = shuffled_w2
 
-        if current_platform.is_cpu():
+        if current_platform.is_xpu():
+            import intel_extension_for_pytorch as ipex
+            layer.ipex_fusion = ipex.llm.modules.GatedMLPMOE(
+                layer.w13_weight,
+                layer.w2_weight,
+                use_prepack=True,
+            )
+        elif current_platform.is_cpu():
             if current_platform.get_cpu_architecture() == CpuArchEnum.X86:
                 from vllm.model_executor.layers.fused_moe import cpu_fused_moe
                 dtype = layer.w13_weight.dtype
@@ -509,6 +516,44 @@ def forward_cpu(
             activation,
         )
 
+    def forward_xpu(
+        self,
+        layer: torch.nn.Module,
+        x: torch.Tensor,
+        use_grouped_topk: bool,
+        top_k: int,
+        router_logits: torch.Tensor,
+        renormalize: bool,
+        topk_group: Optional[int] = None,
+        num_expert_group: Optional[int] = None,
+        global_num_experts: int = -1,
+        expert_map: Optional[torch.Tensor] = None,
+        custom_routing_function: Optional[Callable] = None,
+        scoring_func: str = "softmax",
+        e_score_correction_bias: Optional[torch.Tensor] = None,
+        apply_router_weight_on_input: bool = False,
+        activation: str = "silu",
+        enable_eplb: bool = False,
+        expert_load_view: Optional[torch.Tensor] = None,
+        logical_to_physical_map: Optional[torch.Tensor] = None,
+        logical_replica_count: Optional[torch.Tensor] = None,
+    ):
+        if enable_eplb is not False or expert_load_view is not None or \
+                logical_to_physical_map is not None or \
+                logical_replica_count is not None:
+            raise NotImplementedError("Expert load balancing is not supported "
+                                      "for XPU.")
+        assert custom_routing_function is None
+        return layer.ipex_fusion(
+            x,
+            use_grouped_topk,
+            top_k,
+            router_logits,
+            renormalize,
+            topk_group,
+            num_expert_group,
+        )
+
     def forward_tpu(
         self,
         layer: torch.nn.Module,