[Model] Update support for NemotronNAS models (#15008)

Signed-off-by: Nave Assaf <nassaf@nvidia.com>

vllm/config.py

@@ -411,6 +411,7 @@ class ModelConfig:
 
         self.is_attention_free = self._init_attention_free()
         self.is_hybrid = self._init_is_hybrid()
+        self.has_noops = self._init_has_noops()
         self.has_inner_state = self._init_has_inner_state()
 
         if current_platform.is_neuron():
@@ -510,6 +511,10 @@ class ModelConfig:
     def _init_is_hybrid(self) -> bool:
         return self.registry.is_hybrid_model(self.architectures)
 
+    def _init_has_noops(self) -> bool:
+        architectures = getattr(self.hf_config, "architectures", [])
+        return self.registry.is_noops_model(architectures)
+
     def _init_has_inner_state(self) -> bool:
         return self.registry.model_has_inner_state(self.architectures)
 
@@ -872,6 +877,14 @@ class ModelConfig:
             return getattr(self.hf_config.attn_config, "kv_n_heads",
                            self.hf_config.num_attention_heads)
 
+        if self.hf_config.model_type == "nemotron-nas":
+            for block in self.hf_config.block_configs:
+                if not block.attention.no_op:
+                    return self.hf_config.num_attention_heads \
+                        // block.attention.n_heads_in_group
+
+            raise RuntimeError("Couldn't determine number of kv heads")
+
         if self.is_attention_free:
             return 0
 
@@ -940,7 +953,9 @@ class ModelConfig:
         # This function relies on 'layers_block_type' in hf_config,
         # for w/o this attribute, we will need to have workarounds like so
         attn_block_type = block_type == LayerBlockType.attention
-        is_transformer = not self.is_hybrid and not self.is_attention_free
+        is_transformer = not self.is_hybrid and \
+                            not self.has_noops and \
+                            not self.is_attention_free
         start, end = self.get_layers_start_end_indices(parallel_config)
 
         if is_transformer:
@@ -951,6 +966,10 @@ class ModelConfig:
             # Note that this code assumes there
             # is only one type of attention-free block type.
             return 0 if attn_block_type else end - start
+        elif self.has_noops:
+            block_configs = self.hf_config.block_configs
+            return sum(not bc.attention.no_op
+                       for bc in block_configs[start:end])
         else:
             # Hybrid model
             layers_block_type_value = getattr(self.hf_config,