Fix CuTe DSL DSA paged MQA export (#30627)

python/sglang/jit_kernel/dsa/__init__.py

@@ -1,4 +1,12 @@
-from sglang.srt.utils import is_hip
+from sglang.srt.utils import is_cuda
+
+_is_cuda = is_cuda()
+
+if _is_cuda:
+    from .cutedsl_paged_mqa_logits import CuteDSLPagedMQALogitsRunner, pick_dsl_expand
+else:
+    CuteDSLPagedMQALogitsRunner = None
+    pick_dsl_expand = None
 
 from .paged_mqa_logits import (
     aiter_paged_mqa_logits,
@@ -7,10 +15,6 @@ from .paged_mqa_logits import (
     deepgemm_paged_mqa_logits_split,
 )
 
-if not is_hip():
-    # Preserve the original eager import behavior on non-ROCm platforms.
-    from .cutedsl_paged_mqa_logits import CuteDSLPagedMQALogitsRunner, pick_dsl_expand
-
 __all__ = [
     "CuteDSLPagedMQALogitsRunner",
     "pick_dsl_expand",

python/sglang/srt/layers/attention/dsa/dsa_indexer.py

@@ -58,6 +58,7 @@ global _use_multi_stream
 _is_cuda = is_cuda()
 _is_hip = is_hip()
 _is_npu = is_npu()
+
 if not _is_npu:
     from sglang.jit_kernel.dsa import (
         aiter_paged_mqa_logits,
@@ -71,11 +72,11 @@ else:
     deepgemm_paged_mqa_logits_native = None
     deepgemm_paged_mqa_logits_split = None
 
-if not _is_hip and not _is_npu:
+if _is_cuda:
-    # Preserve the original eager import behavior on non-ROCm platforms.
     from sglang.jit_kernel.dsa import pick_dsl_expand
 else:
     pick_dsl_expand = None
+
 _use_aiter = get_bool_env_var("SGLANG_USE_AITER") and _is_hip
 _is_fp8_fnuz = is_fp8_fnuz()
 _is_gfx95_supported = is_gfx95_supported()
@@ -928,7 +929,7 @@ class Indexer(MultiPlatformOp):
             and forward_batch.forward_mode.is_target_verify()
             and next_n >= 2
         ):
-            assert pick_dsl_expand is not None, "Not supported on AMD/ROCm. "
+            assert pick_dsl_expand is not None, "CuTe DSL paged MQA is CUDA-only."
             dsl_expand_factor, dsl_atom = pick_dsl_expand(
                 next_n,
                 batch_size=B,