Contributed by Mellanox to the Linux 5.3 kernel is an IPMB driver for the Intelligent Platform Management Bus.
IPMB initially didn’t ring a bell but after checking out the new driver and its associated documentation, it sounds quite interesting for supported server platforms.
The Intelligent Platform Management Bus or IPMB, is an I2C bus that provides a standardized interconnection between different boards within a chassis. This interconnection is between the baseboard management (BMC) and chassis electronics. IPMB is also associated with the messaging protocol through the IPMB bus.
The devices using the IPMB are usually management controllers that perform management functions such as servicing the front panel interface, monitoring the baseboard, hot-swapping disk drivers in the system chassis, etc…
When an IPMB is implemented in the system, the BMC serves as a controller to give system software access to the IPMB. The BMC sends IPMI requests to a device (usually a Satellite Management Controller or Satellite MC) via IPMB and the device sends a response back to the BMC.
So along with IPMI fixes for Linux 5.3 is this IPMB driver so Linux can serve as a slave device / satellite MC on an IPMI network.