Xen PCI-device stub driver

modulename: xen-pciback.ko

configname: CONFIG_XEN_PCIDEV_STUB

Linux Kernel Configuration
└─>Device Drivers
└─>Xen driver support
└─>PCI support
└─>Xen PCI-device stub driver
In linux kernel since version 5.2 (release Date: 2019-07-07)  
The PCI device stub driver provides limited version of the PCI
device backend driver without para-virtualized support for guests.
If you select this to be a module, you will need to make sure no
other driver has bound to the device(s) you want to make visible to
other guests.

The "hide" parameter (only applicable if backend driver is compiled
into the kernel) allows you to bind the PCI devices to this module
from the default device drivers. The argument is the list of PCI BDFs:
xen-pciback.hide=(03:00.0)(04:00.0)

If in doubt, say m.

source code: