MSI Interrupt Support

configname: CONFIG_NTB_MSI

Linux Kernel Configuration
└─>Device Drivers
└─>Non-Transparent Bridge support
└─>MSI Interrupt Support
In linux kernel since version 5.1 (release Date: 2019-05-05)  
Support using MSI interrupt forwarding instead of (or in addition to)
hardware doorbells. MSI interrupts typically offer lower latency
than doorbells and more MSI interrupts can be made available to
clients. However this requires an extra memory window and support
in the hardware driver for creating the MSI interrupts.

If unsure, say N.