Comment 0 for bug 1770845

Because of
nazar-pc@nazar-pc ~> cat '/boot/config-4.15.0-21-generic' | grep CONFIG_USB_XHCI_HCD
CONFIG_USB_XHCI_HCD=y

Following doesn't work:
nazar-pc@nazar-pc ~> cat /etc/modprobe.d/gpu-passthrough.conf
options vfio-pci ids=10de:1b06,10de:10ef,1b21:2142
softdep nouveau pre: vfio-pci
softdep xhci_hcd pre: vfio-pci

GPU is fine (first 2 IDs), but USB controller is always occupied by xhci_hcd and I can't change that while xhci_hcd is built-in.

I'd like you to resolve this issue by either embedding vfio-pci module too (prefered solution) or making xhci_hcd optional.

There are some discussions withot clean solution online like this: https://www.reddit.com/r/VFIO/comments/4o6wla/cant_get_vfiopci_to_bind_to_usb_30_card_at_boot/

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: linux-image-4.15.0-21-generic 4.15.0-21.22
ProcVersionSignature: Ubuntu 4.15.0-21.22-generic 4.15.17
Uname: Linux 4.15.0-21-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version k4.15.0-21-generic.
ApportVersion: 2.20.10-0ubuntu2
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 1: S51 [SB Omni Surround 5.1], device 0: USB Audio [USB Audio]
   Subdevices: 0/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC1D0c: nazar-pc 2226 F...m pulseaudio
 /dev/snd/pcmC1D0p: nazar-pc 2226 F...m pulseaudio
 /dev/snd/controlC1: nazar-pc 2226 F.... pulseaudio
                      nazar-pc 2267 F.... volumeicon
Card1.Amixer.info:
 Card hw:1 'S51'/'Creative Technology Ltd SB Omni Surround 5.1 at usb-0000:00:14.0-9.2, full spee'
   Mixer name : 'USB Mixer'
   Components : 'USB041e:322c'
   Controls : 12
   Simple ctrls : 5
CurrentDesktop: Custom
Date: Sat May 12 16:44:11 2018
IwConfig: Error: [Errno 2] Немає такого файла або каталогу: 'iwconfig': 'iwconfig'
MachineType: Micro-Star International Co., Ltd. MS-7B45
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/root/boot/vmlinuz-4.15.0-21-generic root=UUID=5170aca4-061a-4c6c-ab00-bd7fc8ae6030 ro rootflags=subvol=root nosplash intel_pstate=disable scsi_mod.use_blk_mq=1 intel_iommu=on
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-21-generic N/A
 linux-backports-modules-4.15.0-21-generic N/A
 linux-firmware 1.173
RfKill: Error: [Errno 2] Немає такого файла або каталогу: 'rfkill': 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/29/2018
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: A.51
dmi.board.asset.tag: Default string
dmi.board.name: Z370 GAMING PRO CARBON (MS-7B45)
dmi.board.vendor: Micro-Star International Co., Ltd.
dmi.board.version: 2.0
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Micro-Star International Co., Ltd.
dmi.chassis.version: 2.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrA.51:bd03/29/2018:svnMicro-StarInternationalCo.,Ltd.:pnMS-7B45:pvr2.0:rvnMicro-StarInternationalCo.,Ltd.:rnZ370GAMINGPROCARBON(MS-7B45):rvr2.0:cvnMicro-StarInternationalCo.,Ltd.:ct3:cvr2.0:
dmi.product.family: Default string
dmi.product.name: MS-7B45
dmi.product.version: 2.0
dmi.sys.vendor: Micro-Star International Co., Ltd.