1.. SPDX-License-Identifier: BSD-3-Clause 2 Copyright(c) 2018 Intel Corporation. 3 4NTB Rawdev Driver 5================= 6 7The ``ntb`` rawdev driver provides a non-transparent bridge between two 8separate hosts so that they can communicate with each other. Thus, many 9user cases can benefit from this, such as fault tolerance and visual 10acceleration. 11 12This PMD allows two hosts to handshake for device start and stop, memory 13allocation for the peer to access and read/write allocated memory from peer. 14Also, the PMD allows to use doorbell registers to notify the peer and share 15some information by using scratchpad registers. 16 17BIOS setting on Intel Skylake 18----------------------------- 19 20Intel Non-transparent Bridge needs special BIOS setting. Since the PMD only 21supports Intel Skylake platform, introduce BIOS setting here. The referencce 22is https://www.intel.com/content/dam/support/us/en/documents/server-products/Intel_Xeon_Processor_Scalable_Family_BIOS_User_Guide.pdf 23 24- Set the needed PCIe port as NTB to NTB mode on both hosts. 25- Enable NTB bars and set bar size of bar 23 and bar 45 as 12-29 (2K-512M) 26 on both hosts. Note that bar size on both hosts should be the same. 27- Disable split bars for both hosts. 28- Set crosslink control override as DSD/USP on one host, USD/DSP on 29 another host. 30- Disable PCIe PII SSC (Spread Spectrum Clocking) for both hosts. This 31 is a hardware requirement. 32 33Build Options 34------------- 35 36- ``CONFIG_RTE_LIBRTE_PMD_NTB_RAWDEV`` (default ``y``) 37 38 Toggle compilation of the ``ntb`` driver. 39 40Device Setup 41------------ 42 43The Intel NTB devices need to be bound to a DPDK-supported kernel driver 44to use, i.e. igb_uio, vfio. The ``dpdk-devbind.py`` script can be used to 45show devices status and to bind them to a suitable kernel driver. They will 46appear under the category of "Misc (rawdev) devices". 47 48Limitation 49---------- 50 51- The FIFO hasn't been introduced and will come in 19.11 release. 52- This PMD only supports Intel Skylake platform. 53