What were you trying to do that didn't work?

Both the libvirt API and virsh aren't able to return me mtty as a viable device for creating mediated devices.

That said, both the API and virsh are able to return me the list of mediated devices that were created from any mtty type.

Please provide the package NVR for which bug is seen:

libvirt-8.0.0

How reproducible:

Always

Steps to reproduce

1. ensure that you built and loaded the mtty kernel module

lsmod | grep mtty

1. go check that sysfs shows you that mtty supports mdev creation with 2 types :

$ ll /sys/class/mdev_bus/mtty/mdev_supported_types/
total 0
drwxr-xr-x 4 root root 0 Oct 12 18:49 ./
drwxr-xr-x 6 root root 0 Oct 12 16:24 ../
drwxr-xr-x 3 root root 0 Oct 12 18:49 mtty-1/
drwxr-xr-x 3 root root 0 Oct 12 18:49 mtty-2/

1. ask virsh to give you the list of mdev-capable devices

$  sudo virsh nodedev-list --cap mdev_types

(nothing)

Expected results

you should see 'virtual/mtty' as a result.

Actual results

(nothing shows up)