Host Memory Copy Kernel¶
This is a Host Memory Example to describe how data can be copied between host-only buffer and device-only buffer using User Copy Kernel.
KEY CONCEPTS: host memory
KEYWORDS: XCL_MEM_EXT_HOST_ONLY, CL_MEM_HOST_NO_ACCESS, enqueueMapBuffer
Here a user copy kernel is instantiated inside container which copies data between host and device memory.
Host only buffer is created using XCL_MEM_EXT_HOST_ONLY
flag whereas device only buffer is created using CL_MEM_HOST_NO_ACCESS
flag. The following data transfers take place in the example -
Enqueue kernel
copy_kernel
to copy the HOST_ONLY input bufferbuffer_in_host
into DEVICE_ONLY input bufferbuffer_in_dev
.Enqueue kernel
krnl_vadd
to do computations on DEVICE_ONLY input bufferbuffer_in_dev
and put output in DEVICE_ONLY output bufferbuffer_out_dev
.Enqueue kernel
copy_kernel
to copy the DEVICE_ONLY output bufferbuffer_out_dev
into HOST_ONLY output bufferbuffer_out_host
.
EXCLUDED PLATFORMS:
Alveo U25 SmartNIC
Alveo U30
Alveo U50lv
Alveo U50 gen3x4
All Embedded Zynq Platforms, i.e zc702, zcu102 etc
All Versal Platforms, i.e vck190 etc
All Platforms with 2019 Version
All Platforms with 2018 Version
Samsung U.2 SmartSSD
DESIGN FILES¶
Application code is located in the src directory. Accelerator binary files will be compiled to the xclbin directory. The xclbin directory is required by the Makefile and its contents will be filled during compilation. A listing of all the files in this example is shown below
src/copy_kernel.cpp
src/host.cpp
src/krnl_vadd.cpp
Access these files in the github repo by clicking here.
COMMAND LINE ARGUMENTS¶
Once the environment has been configured, the application can be executed by
./host_memory_copy_kernel.exe <krnl_vadd XCLBIN>