Steps required for p2p data transfer - 2022.2 English - XD099

To transfer the data through p2p the following steps are needed

1. Enable the p2p of the source device

2. Declare the source buffer out1 as P2P buffer

Step 1: Enabling p2p of the device

sudo /opt/xilinx/xrt/bin/xbutil configure --device 0000:65:00.1 --p2p enable

After the warm reboot (sudo reboot now) check the p2p enablement status through xbutil examine

xbutil examine -d 0000:65:00.1 -r platform

----------------------------------------------------
1/1 [0000:65:00.1] : xilinx_u50_gen3x16_xdma_base_5
----------------------------------------------------
Platform
    ...
    ...
   P2P Status             : enabled

Step 2: P2P version of the host-code inspection

The final p2p version of the host code is host_p2p.cpp. There are only two differences

1. Output buffer of the source device is declared as p2p buffer

auto out1 = xrt::bo(device1, vector_size_bytes, xrt::bo::flags::p2p, krnl.group_id(1));

2. Output buffer synchronization of the source device is commented out out1.sync(XCL_BO_SYNC_BO_FROM_DEVICE)

 for (int i = 0; i < loop; i++) {
  //out1.sync(XCL_BO_SYNC_BO_FROM_DEVICE);
  in2.sync(XCL_BO_SYNC_BO_TO_DEVICE);
}