Intel Overhauls & Replaces Its RDMA Linux Driver

Intel has wrapped up a 3+ year effort to overhaul and replace its existing RDMA (Remote Direct Memory Access) driver. With Linux 5.14 is their shiny new "IRDMA" driver while their former driver is being immediately removed.

Linux 5.14 is landing Intel's replacement RDMA driver that is a complete rewrite of their older driver and continues supporting the older hardware as well as better supporting new/future hardware. Intel has been working on this new unified Ethernet Protocol Driver for RDMA (named the "irdma" driver) for X722 iWARP hardware as well as newer E810 hardware where the RDMA support isn't in place with their current (now prior) mainline driver. The IRDMA driver is a replacement to the existing i40iw kernel module that is being stripped from the kernel tree.

The X722 and E810 network adapters continue working with the i40e and ICE network drivers while this new Intel RDMA driver is just for handling the remote direct memory access functionality. With the E810 there is support in the new driver for RDMA over Converged Ethernet (RoCEv2) or switching back to iWARP.

While normally when a driver is being replaced in the kernel it's first marked as deprecated for some time, in the case of this Intel driver switch the i40iw driver is already being deleted with Linux 5.14 and just providing this new replacement. Previous to this Intel has been offering the IRDMA driver for X722/E810 hardware as an out-of-tree Linux driver available from Intel.com.

The RDMA pull to Linux 5.14 is thus a large one at more than 38k lines of new code added and 34k lines of code removed in this big Intel RDMA overhaul.