[OpenVINO] Windows Support

backends/openvino/CMakeLists.txt

@@ -35,7 +35,11 @@ include(${EXECUTORCH_ROOT}/tools/cmake/Utils.cmake)
 add_library(openvino_backend STATIC)
 
 # Enable exceptions and RTTI for OpenVINO backend
-target_compile_options(openvino_backend PRIVATE -frtti -fexceptions)
+target_compile_options(
+  openvino_backend
+  PRIVATE $<$<CXX_COMPILER_ID:MSVC>:/GR /EHsc>
+          $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-frtti -fexceptions>
+)
 
 # Add source files for OpenVINO backend
 target_sources(

backends/openvino/README.md

@@ -14,20 +14,26 @@ For more information on the supported hardware, please refer to [OpenVINO System
 
 ## Quick Start (pip wheel)
 
-On Linux, the OpenVINO backend is included in the ExecuTorch pip wheel. Install the OpenVINO runtime to activate it:
+On Linux and Windows, the OpenVINO backend is included in the ExecuTorch pip wheel. Install the OpenVINO runtime to activate it:
 
 ```bash
 pip install executorch[openvino]
 ```
 
-The backend automatically discovers the OpenVINO C library from the pip-installed package — no `LD_LIBRARY_PATH` setup is needed.
+The backend automatically discovers the OpenVINO C library from the pip-installed package — no `LD_LIBRARY_PATH` (Linux) or `PATH` (Windows) setup is needed.
 
 If auto-discovery fails (e.g. non-standard install), you can point to the library explicitly:
 
+**Linux:**
 ```bash
 export OPENVINO_LIB_PATH=$(python3 -c "import openvino, os; print(os.path.join(os.path.dirname(openvino.__file__), 'libs', 'libopenvino_c.so'))")
 ```
 
+**Windows (PowerShell):**
+```powershell
+$env:OPENVINO_LIB_PATH = python -c "import openvino, os; print(os.path.join(os.path.dirname(openvino.__file__), 'libs', 'openvino_c.dll'))"
+```
+
 Verify the backend is available:
 
 ```python
@@ -44,50 +50,169 @@ print(_get_registered_backend_names())
 executorch
 ├── backends
 │   └── openvino
+│       ├── _passes
+│       │   ├── __init__.py
+│       │   └── decompose_floor_divide_pass.py
 │       ├── quantizer
-│           ├── observers
-│               └── nncf_observers.py
-│           ├── __init__.py
-│           └── quantizer.py
+│       │   ├── __init__.py
+│       │   ├── llm_compression.py
+│       │   ├── observers.py
+│       │   └── quantizer.py
 │       ├── runtime
-│           ├── OpenvinoApi.h
-│           ├── OpenvinoBackend.cpp
-│           └── OpenvinoBackend.h
+│       │   ├── OpenvinoApi.h
+│       │   ├── OpenvinoBackend.cpp
+│       │   └── OpenvinoBackend.h
 │       ├── scripts
-│           └── openvino_build.sh
+│       │   └── openvino_build.sh
+│       ├── test
+│       │   └── tester
+│       │       ├── __init__.py
+│       │       └── tester.py
 │       ├── tests
+│       │   ├── models
+│       │   │   └── test_classification.py
+│       │   ├── ops
+│       │   │   ├── base_openvino_op_test.py
+│       │   │   └── test_*.py
+│       │   ├── quantizer
+│       │   │   ├── synthetic_test_models.py
+│       │   │   └── test_llm_compression.py
+│       │   ├── README.md
+│       │   └── test_runner.py
 │       ├── CMakeLists.txt
 │       ├── README.md
 │       ├── __init__.py
 │       ├── partitioner.py
 │       ├── preprocess.py
 │       └── requirements.txt
 └── examples
-    └── openvino
-        ├── aot_optimize_and_infer.py
-        └── README.md
+    └── openvino                          # See examples/openvino/README.md
 ```
 
 ## Build Instructions
 
-### Prerequisites
+### Setup
+
+Follow the steps below to setup your build environment:
+
+
+1. **Create a Virtual Environment**
+- Create a virtual environment and activate it by executing the commands below.
+
+   **Linux:**
+   ```bash
+   python -m venv env
+   source env/bin/activate
+   ```
+
+   **Windows (PowerShell):**
+   ```powershell
+   python -m venv env
+   env\Scripts\Activate.ps1
+   ```
+2. **Clone ExecuTorch Repository from GitHub**
+- On Windows, enable symlinks before cloning. Refer to [Building from Source](https://docs.pytorch.org/executorch/main/using-executorch-building-from-source.html#environment-setup) for more details.
+- Clone Executorch repository by executing the command below.
+   ```bash
+   git clone --recurse-submodules https://github.com/pytorch/executorch.git
+   ```
+3. **Build ExecuTorch with OpenVINO Backend**
+- The following commands build and install ExecuTorch with the OpenVINO backend into `cmake-out`.
+
+   **Linux:**
+   ```bash
+   cmake -DCMAKE_INSTALL_PREFIX=cmake-out \
+         -DCMAKE_BUILD_TYPE=Release \
+         -DEXECUTORCH_BUILD_OPENVINO=ON \
+         -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON \
+         -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON \
+         -DEXECUTORCH_BUILD_EXTENSION_NAMED_DATA_MAP=ON \
+         -DEXECUTORCH_BUILD_EXTENSION_RUNNER_UTIL=ON \
+         -DEXECUTORCH_BUILD_EXTENSION_FLAT_TENSOR=ON \
+         -DEXECUTORCH_BUILD_EXTENSION_TENSOR=ON \
+         -DEXECUTORCH_BUILD_EXECUTOR_RUNNER=ON \
+         -DEXECUTORCH_BUILD_KERNELS_QUANTIZED=ON \
+         -Bcmake-out
+   cmake --build cmake-out --target install --config Release -j $(nproc)
+   ```
+
+   **Windows (PowerShell):**
+   ```powershell
+   cmake -DCMAKE_INSTALL_PREFIX=cmake-out `
+         -DCMAKE_BUILD_TYPE=Release `
+         -DEXECUTORCH_BUILD_OPENVINO=ON `
+         -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON `
+         -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON `
+         -DEXECUTORCH_BUILD_EXTENSION_NAMED_DATA_MAP=ON `
+         -DEXECUTORCH_BUILD_EXTENSION_RUNNER_UTIL=ON `
+         -DEXECUTORCH_BUILD_EXTENSION_FLAT_TENSOR=ON `
+         -DEXECUTORCH_BUILD_EXTENSION_TENSOR=ON `
+         -DEXECUTORCH_BUILD_EXECUTOR_RUNNER=ON `
+         -DEXECUTORCH_BUILD_KERNELS_QUANTIZED=ON `
+         -Bcmake-out
+   cmake --build cmake-out --target install --config Release -j $env:NUMBER_OF_PROCESSORS
+   ```
+
+   To additionally build with LLM extension support, append `-DEXECUTORCH_BUILD_EXTENSION_LLM=ON -DEXECUTORCH_BUILD_EXTENSION_LLM_RUNNER=ON` to the configure step.
+
+#### Build Python Package with Pybindings
+
+Compiles and installs the ExecuTorch Python package with the OpenVINO backend into your Python environment, enabling python bindings required to execute OpenVINO backend tests and `aot_optimize_and_infer.py` script inside `executorch/examples/openvino` folder.
+
+**Linux:**
+```bash
+pip install -r backends/openvino/requirements.txt
+CMAKE_ARGS="-DEXECUTORCH_BUILD_OPENVINO=ON -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON" \
+CMAKE_BUILD_ARGS="--target openvino_backend" \
+./install_executorch.sh --use-pt-pinned-commit
+```
+- On Linux, `backends/openvino/scripts/openvino_build.sh` can be used as a convenience wrapper with `--enable_python`, `--cpp_runtime`, and `--cpp_runtime_llm` options instead of running the above commands directly.
+
+**Windows (PowerShell):**
+```powershell
+pip install -r backends/openvino/requirements.txt
+$env:CMAKE_ARGS = "-DEXECUTORCH_BUILD_OPENVINO=ON -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON"
+$env:CMAKE_BUILD_ARGS = "--target openvino_backend"
+.\install_executorch.bat --use-pt-pinned-commit
+```
+
+
+
+For more information about ExecuTorch environment setup, refer to the [Environment Setup](https://pytorch.org/executorch/main/getting-started-setup#environment-setup) guide.
+
+## Runtime Setup
+
+OpenVINO is a runtime-only dependency — it is not required at build time. The backend discovers and loads the OpenVINO C library dynamically when first used. You can provide the library via pip (recommended) or a manual install.
 
-Before you begin, ensure you have openvino installed and configured on your system.
+### Install via pip (Recommended)
+
+```bash
+pip install openvino
+```
 
 ### Use OpenVINO from Release Packages
 
 1. Download the OpenVINO release package from [here](https://docs.openvino.ai/2025/get-started/install-openvino.html). Make sure to select your configuration and click on **OpenVINO Archives** under the distribution section to download the appropriate archive for your platform.
 
 2. Extract the release package from the archive and set the environment variables.
 
+   **Linux:**
    ```bash
    tar -zxf openvino_toolkit_<your_release_configuration>.tgz
    cd openvino_toolkit_<your_release_configuration>
    source setupvars.sh
    ```
 
+   **Windows (PowerShell):**
+   ```powershell
+   Expand-Archive openvino_toolkit_<your_release_configuration>.zip
+   cd openvino_toolkit_<your_release_configuration>
+   .\setupvars.ps1
+   ```
+
 ### (Optional) Build OpenVINO from Source
 
+**Linux:**
 ```bash
 git clone https://github.com/openvinotoolkit/openvino.git
 cd openvino
@@ -103,46 +228,23 @@ cd <your_preferred_install_location>
 source setupvars.sh
 ```
 
-For more information about OpenVINO build, refer to the [OpenVINO Build Instructions](https://github.com/openvinotoolkit/openvino/blob/master/docs/dev/build_linux.md).
-
-### Setup
-
-Follow the steps below to setup your build environment:
-
-
-1. **Create a Virtual Environment**
-- Create a virtual environment and activate it by executing the commands below.
-   ```bash
-   python -m venv env
-   source env/bin/activate
-   ```
-2. **Clone ExecuTorch Repository from Github**
-- Clone Executorch repository by executing the command below.
-   ```bash
-   git clone --recurse-submodules https://github.com/pytorch/executorch.git
-   ```
-3. **Build ExecuTorch with OpenVINO Backend**
-- Ensure that you are inside `executorch/backends/openvino/scripts` directory. The following command builds and installs ExecuTorch with the OpenVINO backend, also compiles the C++ runtime libraries and binaries into `<executorch_root>/cmake-out` for quick inference testing.
-   ```bash
-   openvino_build.sh
-   ```
-- Optionally, `openvino_build.sh` script can be used to build python package or C++ libraries/binaries seperately.
+**Windows (PowerShell):**
+```powershell
+git clone https://github.com/openvinotoolkit/openvino.git
+cd openvino
+git submodule update --init --recursive
+mkdir build; cd build
+cmake .. -DCMAKE_BUILD_TYPE=Release -DENABLE_PYTHON=ON
+cmake --build . --config Release -j $env:NUMBER_OF_PROCESSORS
 
-   **Build OpenVINO Backend Python Package with Pybindings**: To build and install the OpenVINO backend Python package with Python bindings, run the `openvino_build.sh` script with the `--enable_python` argument as shown in the below command. This will compile and install the ExecuTorch Python package with the OpenVINO backend into your Python environment. This option will also enable python bindings required to execute OpenVINO backend tests and `aot_optimize_and_infer.py` script inside `executorch/examples/openvino` folder.
-     ```bash
-   ./openvino_build.sh --enable_python
-   ```
-   **Build C++ Runtime Libraries for OpenVINO Backend**: Run the `openvino_build.sh` script with the `--cpp_runtime` flag to build the C++ runtime libraries as shown in the below command. The compiled libraries files and binaries can be found in the `<executorch_root>/cmake-out` directory. The binary located at `<executorch_root>/cmake-out/executor_runner` can be used to run inference with vision models.
-     ```bash
-   ./openvino_build.sh --cpp_runtime
-   ```
-   **Build C++ Runtime Libraries with LLM Extension**: Run the `openvino_build.sh` script with the `--cpp_runtime_llm` flag to build the C++ runtime libraries with LLM extension as shown in the below command. Use this option instead of `--cpp_runtime` for LLM extension support which is required by LLM examples.
-     ```bash
-   ./openvino_build.sh --cpp_runtime_llm
-   ```
+cd ..
+cmake --install build --prefix <your_preferred_install_location>
+cd <your_preferred_install_location>
+.\setupvars.ps1
+```
 
-For more information about ExecuTorch environment setup, refer to the [Environment Setup](https://pytorch.org/executorch/main/getting-started-setup#environment-setup) guide.
+For more information about OpenVINO build, refer to the [OpenVINO Build Instructions](https://github.com/openvinotoolkit/openvino/blob/master/docs/dev/build_linux.md).
 
-### Run
+### Examples
 
-Please refer to [README.md](../../examples/openvino/README.md) for instructions on running examples of various of models with openvino backend.
+Please refer to [README.md](../../examples/openvino/README.md) for instructions on running examples of various models with the OpenVINO backend.

backends/openvino/runtime/OpenvinoApi.h

@@ -8,7 +8,11 @@
 
 #pragma once
 
+#ifdef _WIN32
+#include <windows.h>
+#else
 #include <dlfcn.h>
+#endif
 #include <cstddef>
 #include <cstdint>
 #include <memory>
@@ -99,7 +103,11 @@ using ov_shape_free_fn = ov_status_e (*)(ov_shape_t*);
 struct DlCloser {
   void operator()(void* handle) {
     if (handle) {
+#ifdef _WIN32
+      FreeLibrary(static_cast<HMODULE>(handle));
+#else
       dlclose(handle);
+#endif
     }
   }
 };

backends/openvino/runtime/OpenvinoBackend.cpp

@@ -23,17 +23,34 @@ namespace openvino {
 
 namespace {
 
+#ifdef _WIN32
+constexpr const char* kDefaultLibName = "openvino_c.dll";
+#else
 constexpr const char* kDefaultLibName = "libopenvino_c.so";
+#endif
 
 template <typename FuncPtr>
 FuncPtr load_symbol(void* handle, const char* name) {
+#ifdef _WIN32
+  void* sym = reinterpret_cast<void*>(
+      GetProcAddress(static_cast<HMODULE>(handle), name));
+  if (!sym) {
+    ET_LOG(
+        Error,
+        "OpenVINO: failed to resolve symbol '%s': error %lu",
+        name,
+        GetLastError());
+    return nullptr;
+  }
+#else
   dlerror(); // Clear any stale error state.
   void* sym = dlsym(handle, name);
   const char* err = dlerror();
   if (err) {
     ET_LOG(Error, "OpenVINO: failed to resolve symbol '%s': %s", name, err);
     return nullptr;
   }
+#endif
   return reinterpret_cast<FuncPtr>(sym);
 }
 
@@ -47,6 +64,19 @@ bool OpenvinoBackend::ensure_loaded() const {
     const char* lib_path = std::getenv("OPENVINO_LIB_PATH");
     const char* effective_path = lib_path ? lib_path : kDefaultLibName;
 
+#ifdef _WIN32
+    void* handle = static_cast<void*>(LoadLibrary(effective_path));
+    if (!handle) {
+      ET_LOG(
+          Error,
+          "OpenVINO runtime not found (LoadLibrary failed: error %lu). "
+          "Set OPENVINO_LIB_PATH to the full path of 'openvino_c.dll', "
+          "or add its containing directory to PATH, or install with: "
+          "pip install \"openvino>=2025.1.0,<2026.0.0\"",
+          GetLastError());
+      return;
+    }
+#else
     void* handle = dlopen(effective_path, RTLD_NOW | RTLD_LOCAL);
     if (!handle) {
       ET_LOG(
@@ -58,6 +88,7 @@ bool OpenvinoBackend::ensure_loaded() const {
           dlerror());
       return;
     }
+#endif
     lib_handle_.reset(handle);
 
 #define LOAD_SYM(field, symbol_name)                                  \