Comment 2 for bug 1770254

I was able to pass through a PCIE virtual function NIC from the host to the guest. No kernel panics seen in the host.

-- Host with kernel patches --
ubuntu@seuss:~$ ethtool -i enP2p1s0f1
driver: thunder-nicvf
version: 1.0
firmware-version:
expansion-rom-version:
bus-info: 0002:01:00.1
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: yes
supports-priv-flags: no

ubuntu@seuss:~$ readlink /sys/bus/pci/devices/0002\:01\:00.1/driver
../../../../../../../bus/pci/drivers/thunder-nicvf
ubuntu@seuss:~$

ubuntu@seuss:~$ virsh nodedev-detach pci_0002_01_00_1
Device pci_0002_01_00_1 detached

ubuntu@seuss:~$ readlink /sys/bus/pci/devices/0002\:01\:00.1/driver
../../../../../../../bus/pci/drivers/vfio-pci
ubuntu@seuss:~$

-- Bionic Guest --

ubuntu@vm1:~$ lspci -k
00:00.0 Host bridge: Red Hat, Inc. QEMU PCIe Host bridge
        Subsystem: Red Hat, Inc QEMU PCIe Host bridge
00:01.0 PCI bridge: Red Hat, Inc. QEMU PCIe Root port
        Kernel driver in use: pcieport
        Kernel modules: shpchp
00:01.1 PCI bridge: Red Hat, Inc. QEMU PCIe Root port
        Kernel driver in use: pcieport
        Kernel modules: shpchp
00:01.2 PCI bridge: Red Hat, Inc. QEMU PCIe Root port
        Kernel driver in use: pcieport
        Kernel modules: shpchp
00:01.3 PCI bridge: Red Hat, Inc. QEMU PCIe Root port
        Kernel driver in use: pcieport
        Kernel modules: shpchp
00:01.4 PCI bridge: Red Hat, Inc. QEMU PCIe Root port
        Kernel driver in use: pcieport
        Kernel modules: shpchp
00:01.5 PCI bridge: Red Hat, Inc. QEMU PCIe Root port
        Kernel driver in use: pcieport
        Kernel modules: shpchp
01:00.0 Ethernet controller: Red Hat, Inc Virtio network device (rev 01)
        Subsystem: Red Hat, Inc Virtio network device
        Kernel driver in use: virtio-pci
02:00.0 Communication controller: Red Hat, Inc Virtio console (rev 01)
        Subsystem: Red Hat, Inc Virtio console
        Kernel driver in use: virtio-pci
03:00.0 SCSI storage controller: Red Hat, Inc Virtio block device (rev 01)
        Subsystem: Red Hat, Inc Virtio block device
        Kernel driver in use: virtio-pci
04:00.0 SCSI storage controller: Red Hat, Inc Virtio block device (rev 01)
        Subsystem: Red Hat, Inc Virtio block device
        Kernel driver in use: virtio-pci
05:00.0 Ethernet controller: Cavium, Inc. THUNDERX Network Interface Controller virtual function (rev 09)
        Subsystem: Cavium, Inc. THUNDERX Network Interface Controller virtual function
        Kernel driver in use: thunder-nicvf
        Kernel modules: nicvf
ubuntu@vm1:~$

ubuntu@vm1:~$ ethtool -i enp5s0
driver: thunder-nicvf
version: 1.0
firmware-version:
expansion-rom-version:
bus-info: 0000:05:00.0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: yes
supports-priv-flags: no
ubuntu@vm1:~$