I am trying to passthrough a USB card to a guest, but I can't seem to make the VFIO driver stick, instead it seems that the host loads and takes over the card. I have a GPU successfully passed through, so I am sure that vfio/IOMMU are working.

card: Sonnet Allegro USB 3.1, Two-Port USB-C 10Gb PCIe Card (USB3C-2PM-E)
motherboard: ASRock x399 Taichi
CPU: Threadripper 1950x
I tried following the same procedure that I used to passthrough a GPU, which I mostly learned here:

First, get the ID of the card:

~ lspci | grep USB

01:00.0 USB controller: Advanced Micro Devices, Inc. [AMD] Device 43ba (rev 02)

0a:00.0 USB controller: ASMedia Technology Inc. ASM1142 USB 3.1 Host Controller

0b:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) USB 3.0 Host Controller

45:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) USB 3.0 Host Controller

Next. get the vendor, product ID, and an alias, then modify system files accordingly in hopes that it will prevent the card from being grabbed by the host:

~ lspci -nn | grep 0a:00

0a:00.0 USB controller [0c03]: ASMedia Technology Inc. ASM1142 USB 3.1 Host Controller [1b21:1242]

cat /sys/bus/pci/devices/0000:0a:00.0/modalias

pci:v00001B21d00001242sv000016B8sd00007230bc0Csc03i30

~ sudo nano /etc/modprobe.d/local.conf

paste at end:

alias pci:v00001B21d00001242sv000016B8sd00007230bc0Csc03i30 vfio-pci

options vfio-pci ids=1b21:1242

then:

~ sudo update-initramfs -u

and reboot and check if the card is using the vfio driver:

~ lspci -kn | grep -A 2 0a

0a:00.0 0c03: 1b21:1242

    Subsystem: 16b8:7230

    Kernel driver in use: xhci_hcd

I also tried making an override script as per the same blog mentioned above:

sudo nano /sbin/vfio-pci-override-usb.sh





#!/bin/sh



DEVS="0000:0a:00.0"



for DEV in $DEVS; do

echo "vfio-pci" > /sys/bus/pci/devices/$DEV/driver_override

done



modprobe -i vfio-pci



#####



sudo chmod 755 /sbin/vfio-pci-override-usb.sh



sudo nano /etc/modprobe.d/local.conf

commented out previous entry and added:

install vfio-pci /sbin/vfio-pci-override-usb.sh

sudo update-initramfs -u

reboot

but still no good:

 ~ lspci -kn | grep -A 2 0a:00

0a:00.0 0c03: 1b21:1242

    Subsystem: 16b8:7230

    Kernel driver in use: xhci_hcd

also: When I look for the driver, in lspci (to see what else is using it), it brings up a bunch of devices but not 0a:00.

~ lspci -kn | grep -A 2 xhci

    Kernel driver in use: xhci_hcd

01:00.1 0106: 1022:43b6 (rev 02)

    Subsystem: 1b21:1062

--

    Kernel driver in use: xhci_hcd

0b:00.0 1300: 1022:145a

    Subsystem: 1022:145a

--

    Kernel driver in use: xhci_hcd

0c:00.0 1300: 1022:1455

    Subsystem: 1022:1455

--

    Kernel driver in use: xhci_hcd

46:00.0 1300: 1022:1455

    Subsystem: 1022:1455

Next I tried Tried blacklisting the driver:

sudo nano /etc/default/grub



# original: GRUB_CMDLINE_LINUX_DEFAULT=”amd_iommu=on”

# to: 

GRUB_CMDLINE_LINUX_DEFAULT=”modprobe.blacklist=xhci_hcd amd_iommu=on”



##then:

 sudo update-grub



 ##Uncomment in local.conf:

# options vfio-pci ids=1b21:1242



 sudo update-initramfs -u

still no:

lspci -kn | grep -A 2 0a:00

0a:00.0 0c03: 1b21:1242

    Subsystem: 16b8:7230

    Kernel driver in use: xhci_hcd

What else might I try? Am I correct that the kernel driver in use for that device must be vfio-pci?