[Feature] Support minicpmv v2.6 (#2785)

Co-authored-by: Chayenne <zhaochen20@outlook.com>
Co-authored-by: yizhang2077 <1109276519@qq.com>

python/sglang/srt/conversation.py

@@ -452,7 +452,6 @@ def generate_chat_conv(
 
     # Add a blank message for the assistant.
     conv.append_message(conv.roles[1], None)
-
     return conv
 
 
@@ -555,3 +554,17 @@ register_conv_template(
         image_token="<|vision_start|><|image_pad|><|vision_end|>",
     )
 )
+
+# Reference: https://huggingface.co/openbmb/MiniCPM-V-2_6#usage
+register_conv_template(
+    Conversation(
+        name="minicpmv",
+        system_message="You are a helpful assistant",
+        system_template="<|im_start|>system\n{system_message}.",
+        roles=("<|im_start|>user", "<|im_start|>assistant"),
+        sep="<|im_end|>\n",
+        sep_style=SeparatorStyle.ADD_NEW_LINE_SINGLE,
+        stop_str=("<|im_end|>", "<|endoftext|>"),
+        image_token="(<image>./</image>)",
+    )
+)