Linux v5.1.3 - visorbus
# Unisys visorbus configuration
tristate "Unisys visorbus driver"
depends on X86_64 && ACPI
The visorbus driver is a virtualized bus for the Unisys s-Par firmware.
Virtualized devices allow Linux guests on a system to share disks and
network cards that do not have SR-IOV support, and to be accessed using
the partition desktop application. The visorbus driver is required to
discover devices on an s-Par guest, and must be present for any other
s-Par guest driver to function correctly.