introduce shim layers for cudaguard and cudastreamguard

backends/aoti/CMakeLists.txt

@@ -40,13 +40,8 @@ target_compile_options(aoti_common PUBLIC -fexceptions -frtti -fPIC)
 # Ensure symbols are exported properly
 target_link_options(aoti_common PUBLIC -Wl,--export-dynamic)
 
-# Link against PyTorch libraries and standard libraries
-target_link_libraries(
-  aoti_common
-  PUBLIC extension_tensor ${CMAKE_DL_LIBS}
-         # Link PyTorch libraries for AOTI functions
-         ${TORCH_LIBRARIES}
-)
+# Link against ExecuTorch libraries and standard libraries
+target_link_libraries(aoti_common PUBLIC extension_tensor ${CMAKE_DL_LIBS})
 executorch_target_link_options_shared_lib(aoti_common)
 
 install(

backends/aoti/aoti_model_container.h

@@ -77,6 +77,8 @@ struct AOTIDelegateHandle {
   void* so_handle;
   std::string so_path;
   AOTInductorModelContainerHandle container_handle;
+  void* cuda_stream; // cudaStream_t stored as void* to avoid CUDA header
+                     // dependency
 };
 
 } // namespace aoti

backends/aoti/common_shims.cpp

@@ -127,11 +127,18 @@ int32_t aoti_torch_layout_strided() {
 }
 
 // Dtype constants - these return the PyTorch dtype codes
-// Currently only float32 is supported, but using robust enum-based approach
 int32_t aoti_torch_dtype_float32() {
   return 6; // PyTorch's float32 dtype code
 }
 
+int32_t aoti_torch_dtype_bfloat16() {
+  return 15; // PyTorch's bfloat16 dtype code
+}
+
+int32_t aoti_torch_dtype_int64() {
+  return 4; // PyTorch's int64 dtype code
+}
+
 // Cleanup functions
 void cleanup_tensor_metadata() {
   internal::tensor_to_sizes.clear();

backends/aoti/common_shims.h

@@ -58,6 +58,8 @@ AOTITorchError aoti_torch_get_dim(Tensor* tensor, int64_t* ret_dim);
 int32_t aoti_torch_device_type_cpu();
 int32_t aoti_torch_layout_strided();
 int32_t aoti_torch_dtype_float32();
+int32_t aoti_torch_dtype_bfloat16();
+int32_t aoti_torch_dtype_int64();
 
 // Autograd mode functions
 int32_t aoti_torch_grad_mode_is_enabled();

backends/aoti/targets.bzl

@@ -51,7 +51,7 @@ def define_common_targets():
         link_whole = True,
         supports_python_dlopen = True,
         visibility = ["@EXECUTORCH_CLIENTS"],
-        deps = [
+        exported_deps = [
             ":common_shims",
             ":model_container",
         ],

backends/cuda/CMakeLists.txt

@@ -35,8 +35,10 @@ include(${EXECUTORCH_ROOT}/tools/cmake/Utils.cmake)
 find_package_torch()
 
 # CUDA-specific AOTI functionality
-set(_aoti_cuda_sources runtime/cuda_backend.cpp runtime/shims/memory.cpp
-                       runtime/shims/tensor_attribute.cpp runtime/guard.cpp
+set(_aoti_cuda_sources
+    runtime/cuda_backend.cpp runtime/shims/memory.cpp
+    runtime/shims/tensor_attribute.cpp runtime/guard.cpp
+    runtime/shims/cuda_guard.cpp
 )
 add_library(aoti_cuda STATIC ${_aoti_cuda_sources})
 target_include_directories(
@@ -53,10 +55,7 @@ target_link_options(aoti_cuda PUBLIC -Wl,--export-dynamic)
 
 # Link against CUDA::cudart, common AOTI library, and PyTorch CUDA libraries
 target_link_libraries(
-  aoti_cuda
-  PUBLIC aoti_common CUDA::cudart ${CMAKE_DL_LIBS}
-         # Link PyTorch libraries for AOTI CUDA functions
-         ${TORCH_LIBRARIES}
+  aoti_cuda PUBLIC aoti_common CUDA::cudart ${CMAKE_DL_LIBS}
 )
 # If you need other CUDA libraries, link them similarly:
 # target_link_libraries(aoti_cuda PUBLIC CUDA::cublas CUDA::cufft ...)

backends/cuda/runtime/TARGETS

@@ -6,11 +6,13 @@ runtime.cxx_library(
     name = "runtime_shims",
     srcs = [
         "guard.cpp",
+        "shims/cuda_guard.cpp",
         "shims/memory.cpp",
         "shims/tensor_attribute.cpp",
     ],
     headers = [
         "guard.h",
+        "shims/cuda_guard.h",
         "shims/memory.h",
         "shims/tensor_attribute.h",
         "utils.h",
@@ -32,3 +34,25 @@ runtime.cxx_library(
         ("cuda", None, "cuda-lazy"),
     ],
 )
+
+runtime.cxx_library(
+    name = "cuda_backend",
+    srcs = [
+        "cuda_backend.cpp",
+    ],
+    # @lint-ignore BUCKLINT: Avoid `link_whole=True` (https://fburl.com/avoid-link-whole)
+    link_whole = True,
+    supports_python_dlopen = True,
+    # Constructor needed for backend registration.
+    compiler_flags = ["-Wno-global-constructors"],
+    visibility = ["@EXECUTORCH_CLIENTS"],
+    deps = [
+        ":runtime_shims",
+        "//executorch/backends/aoti:aoti_common",
+        "//executorch/runtime/backend:interface",
+        "//executorch/runtime/core/exec_aten/util:tensor_util",
+    ],
+    external_deps = [
+        ("cuda", None, "cuda-lazy"),
+    ],
+)