models: enable deepseek2 (deepseek v3.1 w/ MLA) on the new engine (#13151)

fs/ggml/ggml.go

@@ -250,6 +250,7 @@ func (kv KV) OllamaEngineRequired() bool {
 		"qwen3", "qwen3moe",
 		"qwen3vl", "qwen3vlmoe",
 		"deepseekocr",
+		"deepseek2",
 	}, kv.Architecture())
 }
 

model/models/deepseek2/model.go

@@ -236,6 +236,11 @@ type Model struct {
 }
 
 func New(c fs.Config) (model.Model, error) {
+	if c.Uint("attention.key_length_mla") == 0 {
+		// non-MLA models aren't yet supported
+		return nil, model.ErrUnsupportedModel
+	}
+
 	layers := make([]Layer, c.Uint("block_count"))
 
 	firstDenseLayerIndex := int(c.Uint("leading_dense_block_count"))