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Beehive LevelZero JNI

Baremetal GPU and FPGA programming for Java using Intel's Level Zero API. This project is a Java Native Interface (JNI) binding for Intel's Level Zero. This library is designed to be as closed as possible to the Level Zero API for C++ API, and it supports a subset of the Level Zero 1.4.0 API (Level Zero as in May 2022). This library is used by TornadoVM, and the subset of the Level Zero API 1.4.0 is the minimum required to dispatch SPIR-V kernels on Intel ARC and Intel integrated GPUs under the TornadoVM Runtime. It is, by no means, a complete port of the Level Zero API, but external contributions are very welcome.

Compilation & configuration of the JNI Level Zero API

1) Compile Native Library: Level Zero API

Linux (Tested for Fedora 35-39 and Ubuntu 22.X-24.X)

git clone https://github.com/oneapi-src/level-zero.git
cd level-zero
mkdir build
cd build
cmake ..
cmake --build . --config Release
cmake --build . --config Release --target package

Windows 10/11

Tested Configurations:

Run commands in x64 Native Tools Command Prompt for VS 2022.

git clone https://github.com/oneapi-src/level-zero
cd level-zero
md build
cd build
cmake ..
cmake --build . --config Release

rem check
.\bin\Release\zello_world.exe

Note: If zello_world.exe fails, search for existing Level Zero API DLLs (file names start with ze_, e.g. ze_tracing_layer.dll) in c:\windows\system32 and move them to another folder.

2) Compile Level Zero Java JNI native code

Set the paths to the directory of Level Zero installation. Here are examples:

Linux

scl enable devtoolset-9 bash # << Only for CentOS/RHEL
git clone https://github.com/beehive-lab/levelzero-jni
export ZE_SHARED_LOADER="<path-to-levelzero>/build/lib/libze_loader.so"
export CPLUS_INCLUDE_PATH=<path-to-levelzero>/include:$CPLUS_INCLUDE_PATH
export C_INCLUDE_PATH=<path-to-levelzero>/include:$CPLUS_INCLUDE_PATH
cd levelzero-jni/levelZeroLib
mkdir build
cd build
cmake ..
make

Windows 10/11

Note: Run commands in x64 Native Tools Command Prompt for VS 2022.

git clone https://github.com/beehive-lab/levelzero-jni
set ZE_SHARED_LOADER=%USERPROFILE%\lab\level-zero\build\lib\release\ze_loader.lib
set CPLUS_INCLUDE_PATH=%USERPROFILE%\lab\level-zero\include
set C_INCLUDE_PATH=%USERPROFILE%\lab\level-zero\include

rem add the folder with Intel's Level Zero API DLLs to PATH
set PATH=%USERPROFILE%\lab\level-zero\build\bin\release;%PATH%

cd levelzero-jni\levelZeroLib
md build
cd build
cmake ..
cmake --build . --config Release

Obtain a SPIR-V compiler (Linux and Windows)

In case you want to compile kernels from OpenCL C to SPIR-V and use the Level Zero API, you need to download the llvm-spirv compiler. The implementation we are currently using is Intel LLVM.

3) Compile the Java Library and Run Tests

Linux

mvn clean package
./scripts/run.sh   ## < This script compiles an OpenCL C program to SPIR-V using the llvm-spirv compiler (see 2.1)

The OpenCL C kernel provided for this example is as follows:

__kernel void copyData(__global int* input, __global int* output) {
	uint idx = get_global_id(0);
	output[idx] = input[idx];
}

To compile from OpenCL C to SPIR-V:

clang -cc1 -triple spir copyData.cl -O0 -finclude-default-header -emit-llvm-bc -o copyData.bc
llvm-spirv copyData.bc -o copyData.spv

Windows

Note: Java programs that use levelzero-jni are based on DLLs, which are provided by Intel's Level Zero API. For these programs to find these DLLs, the PATH environment variable must contain the folder that contains the DLLs.

mvn clean package

rem add the folder with Intel's Level Zero API DLLs to PATH
set PATH=%USERPROFILE%\lab\level-zero\build\bin\release;%PATH%

rem copyData.spv file expected in CWD
.\scripts\run.cmd

# more tests
.\scripts\copies.cmd
.\scripts\events.cmd
.\scripts\fences.cmd
.\scripts\kernelTimers.cmd
.\scripts\transferTimers.cmd
.\scripts\largeBuffers.cmd
.\scripts\testZelloWorld.cmd

Some Examples

Instance Driver Pointer

 // Obtain the Level Zero Driver
LevelZeroDriver driver = new LevelZeroDriver();
int result = driver.zeInit(ZeInitFlag.ZE_INIT_FLAG_GPU_ONLY);
LevelZeroUtils.errorLog("zeInit", result);

int[] numDrivers = new int[1];
result = driver.zeDriverGet(numDrivers, null);
LevelZeroUtils.errorLog("zeDriverGet", result);

ZeDriverHandle driverHandler = new ZeDriverHandle(numDrivers[0]);
result = driver.zeDriverGet(numDrivers, driverHandler);
LevelZeroUtils.errorLog("zeDriverGet", result);

Create Level Zero Context

ZeContextDescriptor contextDescription = new ZeContextDescriptor();
LevelZeroContext context = new LevelZeroContext(driverHandler, contextDescription);
result = context.zeContextCreate(driverHandler.getZe_driver_handle_t_ptr()[0]);
LevelZeroUtils.errorLog("zeContextCreate", result);

Allocate Shared Memory:

ZeDeviceMemAllocDescriptor deviceMemAllocDesc = new ZeDeviceMemAllocDescriptor();
deviceMemAllocDesc.setFlags(ZeDeviceMemAllocFlags.ZE_DEVICE_MEM_ALLOC_FLAG_BIAS_UNCACHED);


ZeHostMemAllocDescriptor hostMemAllocDesc = new ZeHostMemAllocDescriptor();
hostMemAllocDesc.setFlags(ZeHostMemAllocFlags.ZE_HOST_MEM_ALLOC_FLAG_BIAS_UNCACHED);


LevelZeroBufferInteger bufferA = new LevelZeroBufferInteger();
result = context.zeMemAllocShared(context.getContextHandle().getContextPtr()[0], deviceMemAllocDesc, hostMemAllocDesc, bufferSize, 1, device.getDeviceHandlerPtr(), bufferA);
LevelZeroUtils.errorLog("zeMemAllocShared", result);

See the full list of examples here.

License

This project is developed at The University of Manchester, and it is fully open source under the MIT license.

Acknowledgments

The work was partially funded by the EU Horizon 2020 Elegant 957286 project, and Intel Coorporation.