spec: add eagle3-v3 support for gpt-oss model (#25794)

src/llama-arch.cpp

@@ -317,6 +317,7 @@ static const std::map<llm_kv, const char *> LLM_KV_NAMES = {
     { LLM_KV_TARGET_LAYERS,         "%s.target_layers"        },
     { LLM_KV_TARGET_HIDDEN_SIZE,    "%s.target_hidden_size"   },
     { LLM_KV_NORM_BEFORE_RESIDUAL,  "%s.norm_before_residual" },
+    { LLM_KV_NORM_BEFORE_FC,        "%s.norm_before_fc"       },
 
     { LLM_KV_SHORTCONV_L_CACHE, "%s.shortconv.l_cache" },
     // sentence-transformers dense modules feature dims

src/llama-arch.h

@@ -363,6 +363,7 @@ enum llm_kv {
     LLM_KV_TARGET_LAYERS,
     LLM_KV_TARGET_HIDDEN_SIZE,
     LLM_KV_NORM_BEFORE_RESIDUAL,
+    LLM_KV_NORM_BEFORE_FC,
 
     LLM_KV_SHORTCONV_L_CACHE,
 

src/llama-hparams.h

@@ -47,6 +47,7 @@ struct llama_hparams {
     bool use_par_res;
     bool swin_norm;
     bool norm_before_residual = false;
+    bool norm_before_fc       = false;
 
     uint32_t n_ctx_train; // context size the model was trained on
     uint32_t n_embd;

src/models/eagle3.cpp

@@ -28,6 +28,10 @@ void llama_model_eagle3::load_arch_hparams(llama_model_loader & ml) {
         LLAMA_LOG_INFO("%s: EAGLE3gnorm_before_residual = true\n", __func__);
     }
 
+    // eagle3 norm_before_fc (optional, default false)
+    // compatible with eagle3.1 (e.g. nvidia/gpt-oss-120b-Eagle3-v3)
+    ml.get_key(LLM_KV_NORM_BEFORE_FC, hparams.norm_before_fc, false);
+
     type = LLM_TYPE_UNKNOWN;
 }
 
@@ -53,6 +57,11 @@ void llama_model_eagle3::load_arch_tensors(llama_model_loader &) {
     // Feature fusion layer: projects 3 target layers to draft hidden size
     fc = create_tensor(tn(LLM_TENSOR_FC, "weight"), {n_embd_inp, n_embd}, 0);
 
+    // RMSNorm on the fused target features (input to fc), only when norm_before_fc is set.
+    if (hparams.norm_before_fc) {
+        output_norm_enc = create_tensor(tn(LLM_TENSOR_ENC_OUTPUT_NORM, "weight"), {n_embd_inp}, 0);
+    }
+
     // Output layer (uses draft vocab size)
     output_norm = create_tensor(tn(LLM_TENSOR_OUTPUT_NORM, "weight"), {n_embd}, 0);
     output      = create_tensor(tn(LLM_TENSOR_OUTPUT,      "weight"), {n_embd, n_draft_vocab}, TENSOR_NOT_REQUIRED);
@@ -130,6 +139,12 @@ llama_model_eagle3::graph<true>::graph(const llama_model & model, const llm_grap
 
     cur = build_inp_embd_enc();
 
+    // RMSNorm on the fused target features before fc
+    if (hparams.norm_before_fc) {
+        cur = build_norm(cur, model.output_norm_enc, NULL, LLM_NORM_RMS, -1);
+        cb(cur, "enc_input_norm", -1);
+    }
+
     // Feature fusion layer
     cur = build_lora_mm(model.fc, cur);
     cb(cur, "fc_out", -1);

src/models/openai-moe.cpp

@@ -116,7 +116,7 @@ llama_model_openai_moe::graph::graph(const llama_model & model, const llm_graph_
 
             cb(cur, "attn_out", il);
         }
-        if (il == n_layer - 1) {
+        if (il == n_layer - 1 && inp_out_ids && cparams.embeddings_nextn_masked) {
             // skip computing output for unused tokens
             cur   = ggml_get_rows(ctx0,   cur, inp_out_ids);
             inpSA = ggml_get_rows(ctx0, inpSA, inp_out_ids);
@@ -154,6 +154,12 @@ llama_model_openai_moe::graph::graph(const llama_model & model, const llm_graph_
     }
     cur = inpL;
 
+    res->t_h_nextn = cur;
+
+    if (!cparams.embeddings_nextn_masked && inp_out_ids) {
+        cur = ggml_get_rows(ctx0, cur, inp_out_ids);
+    }
+
     cur = build_norm(cur,
             model.output_norm, NULL,
             LLM_NORM_RMS, -1);