From 7c195b9151627320b2a4688251adc12975712a86 Mon Sep 17 00:00:00 2001
From: Tuan Nguyen Gia <tnguyeng@amd.com>
Date: Sat, 12 Sep 2026 10:50:41 +0300
Subject: [PATCH] [AMD] Fix Quark load of MiniMax-M3 MXFP4 index_qkv_proj
 (#37254)

---
 python/sglang/srt/models/minimax_m3.py        |  3 +-
 python/sglang/srt/models/minimax_m3_vl.py     |  3 +-
 .../layers/quantization/test_quark_utils.py   | 51 ++++++++++++++++++-
 3 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/python/sglang/srt/models/minimax_m3.py b/python/sglang/srt/models/minimax_m3.py
index fa2c30723..443de34b6 100644
--- a/python/sglang/srt/models/minimax_m3.py
+++ b/python/sglang/srt/models/minimax_m3.py
@@ -1559,7 +1559,8 @@ class MiniMaxM3SparseForCausalLM(nn.Module):
     )
     packed_modules_mapping = {
         "qkv_proj": ["q_proj", "k_proj", "v_proj"],
-        "index_qkv_proj": ["index_q_proj", "index_k_proj", "index_v_proj"],
+        # no index_v_proj in the M3 checkpoint
+        "index_qkv_proj": ["index_q_proj", "index_k_proj"],
         "gate_up_proj": ["gate_proj", "up_proj"],
     }
 
diff --git a/python/sglang/srt/models/minimax_m3_vl.py b/python/sglang/srt/models/minimax_m3_vl.py
index 5eed7654c..68a6e39b2 100644
--- a/python/sglang/srt/models/minimax_m3_vl.py
+++ b/python/sglang/srt/models/minimax_m3_vl.py
@@ -63,7 +63,8 @@ class MiniMaxM3SparseForConditionalGeneration(nn.Module):
     )
     packed_modules_mapping = {
         "qkv_proj": ["q_proj", "k_proj", "v_proj"],
-        "index_qkv_proj": ["index_q_proj", "index_k_proj", "index_v_proj"],
+        # no index_v_proj in the M3 checkpoint
+        "index_qkv_proj": ["index_q_proj", "index_k_proj"],
         "gate_up_proj": ["gate_proj", "up_proj"],
     }
 
diff --git a/test/registered/unit/layers/quantization/test_quark_utils.py b/test/registered/unit/layers/quantization/test_quark_utils.py
index 6ae108bd4..5ed8240b2 100644
--- a/test/registered/unit/layers/quantization/test_quark_utils.py
+++ b/test/registered/unit/layers/quantization/test_quark_utils.py
@@ -8,10 +8,59 @@ import unittest
 
 import torch
 
-from sglang.srt.layers.quantization.quark.utils import e8m0_to_f32
+from sglang.srt.layers.quantization.quark.utils import (
+    e8m0_to_f32,
+    should_ignore_layer,
+)
 from sglang.test.test_utils import CustomTestCase
 
 
+class TestShouldIgnoreLayer(CustomTestCase):
+    """MiniMax-M3 MXFP4: sparse index_qkv_proj packs only q/k (the DSA value
+    projection is disabled, so index_v_proj is absent on disk)."""
+
+    _LAYER = "language_model.model.layers.3.self_attn.index_qkv_proj"
+    _IGNORE = (
+        "language_model.model.layers.3.self_attn.index_q_proj",
+        "language_model.model.layers.3.self_attn.index_k_proj",
+    )
+    # The fix lives in the model: index_qkv_proj maps to only q/k (no v).
+    _MAPPING = {
+        "index_qkv_proj": ["index_q_proj", "index_k_proj"],
+    }
+
+    def test_minimax_dsa_index_qkv_ignored(self):
+        # Both present shards are excluded -> fused module stays bf16, no raise.
+        self.assertTrue(should_ignore_layer(self._LAYER, self._IGNORE, self._MAPPING))
+
+    def test_all_shards_agree_still_works(self):
+        layer = "model.layers.0.self_attn.qkv_proj"
+        ignore = (
+            "model.layers.0.self_attn.q_proj",
+            "model.layers.0.self_attn.k_proj",
+            "model.layers.0.self_attn.v_proj",
+        )
+        mapping = {"qkv_proj": ["q_proj", "k_proj", "v_proj"]}
+        self.assertTrue(should_ignore_layer(layer, ignore, mapping))
+
+    def test_no_shards_ignored(self):
+        layer = "model.layers.0.self_attn.qkv_proj"
+        mapping = {"qkv_proj": ["q_proj", "k_proj", "v_proj"]}
+        self.assertFalse(should_ignore_layer(layer, (), mapping))
+
+    def test_mixed_schemes_raise(self):
+        # Safety net preserved: if a fused module genuinely mixes excluded and
+        # quantized shards, the loader must fail loudly rather than guess.
+        layer = "model.layers.0.self_attn.qkv_proj"
+        ignore = (
+            "model.layers.0.self_attn.q_proj",
+            "model.layers.0.self_attn.k_proj",
+        )  # v_proj NOT excluded -> inconsistent with q/k
+        mapping = {"qkv_proj": ["q_proj", "k_proj", "v_proj"]}
+        with self.assertRaises(ValueError):
+            should_ignore_layer(layer, ignore, mapping)
+
+
 class TestE8M0ToF32(CustomTestCase):
     """Cover OCP MX-format v1.0 e8m0 decoding:
     encoded 0..254 -> 2^(x-127); encoded 255 -> NaN.