Exclude building flashMLA kernels under sm90.

Signed-off-by: Bo Li <[email protected]>

Author: bobboli

cpp/tensorrt_llm/kernels/flashMLA/CMakeLists.txt

@@ -21,3 +21,27 @@ file(GLOB_RECURSE SRC_CU *.cu)
 add_library(flash_mla_src OBJECT ${SRC_CPP} ${SRC_CU})
 set_property(TARGET flash_mla_src PROPERTY POSITION_INDEPENDENT_CODE ON)
 set_property(TARGET flash_mla_src PROPERTY CUDA_RESOLVE_DEVICE_SYMBOLS ON)
+
+# Get all targeted architectures from parent CMake
+if(CMAKE_CUDA_ARCHITECTURES)
+  # Create a list for FlashMLA's supported architectures
+  set(FLASH_MLA_CUDA_ARCHS "")
+
+  # Only include architectures 90 and above
+  foreach(arch ${CMAKE_CUDA_ARCHITECTURES})
+    # Extract the numeric part before any dash
+    string(REGEX MATCH "^([0-9]+)" arch_num "${arch}")
+
+    # Only add architectures 90 and above
+    if(arch_num GREATER_EQUAL 90)
+      list(APPEND FLASH_MLA_CUDA_ARCHS "${arch}")
+    endif()
+  endforeach()
+
+  # Set specific architectures for this target only
+  set_property(TARGET flash_mla_src PROPERTY CUDA_ARCHITECTURES
+                                             ${FLASH_MLA_CUDA_ARCHS})
+
+  # Log which architectures we're building for
+  message(STATUS "Building FlashMLA for architectures: ${FLASH_MLA_CUDA_ARCHS}")
+endif()