Hello,Po-Hsu Lin

$ uname -r
5.11.0-27-generic

$ lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 20.04.2 LTS
Release:	20.04
Codename:	focal



$ sudo vi /etc/modules

vfio
vfio_iommu_type1
vfio_pci
vfio_virqfd
kvm
kvm_intel

:wq

Reboot Ubuntu.

$ lsmod | grep vfio

empty...

$ lsmod | grep kvm

kvm_intel             294912  0
kvm                   819200  1 kvm_intel

$ modinfo vfio
name:           vfio
filename:       (builtin)
softdep:        post: vfio_iommu_type1 vfio_iommu_spapr_tce
alias:          devname:vfio/vfio
alias:          char-major-10-196
description:    VFIO - User Level meta-driver
author:         Alex Williamson <email address hidden>
license:        GPL v2
file:           drivers/vfio/vfio
version:        0.3
parm:           enable_unsafe_noiommu_mode:Enable UNSAFE, no-IOMMU mode.  This mode provides no device isolation, no DMA translation, no host kernel protection, cannot be used for device assignment to virtual machines, requires RAWIO permissions, and will taint the kernel.  If you do not know what this is for, step away. (default: false) (bool)

$ modinfo vfio_iommu_type1
name:           vfio_iommu_type1
filename:       (builtin)
description:    Type1 IOMMU driver for VFIO
author:         Alex Williamson <email address hidden>
license:        GPL v2
file:           drivers/vfio/vfio_iommu_type1
version:        0.2
parm:           allow_unsafe_interrupts:Enable VFIO IOMMU support for on platforms without interrupt remapping support. (bool)
parm:           disable_hugepages:Disable VFIO IOMMU support for IOMMU hugepages. (bool)
parm:           dma_entry_limit:Maximum number of user DMA mappings per container (65535). (uint)

$ modinfo vfio_pci
name:           vfio_pci
filename:       (builtin)
description:    VFIO PCI - User Level meta-driver
author:         Alex Williamson <email address hidden>
license:        GPL v2
file:           drivers/vfio/pci/vfio-pci
version:        0.2
parm:           ids:Initial PCI IDs to add to the vfio driver, format is "vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]" and multiple comma separated entries can be specified (string)
parm:           nointxmask:Disable support for PCI 2.3 style INTx masking.  If this resolves problems for specific devices, report lspci -vvvxxx to <email address hidden> so the device can be fixed automatically via the broken_intx_masking flag. (bool)
parm:           disable_vga:Disable VGA resource access through vfio-pci (bool)
parm:           disable_idle_d3:Disable using the PCI D3 low power state for idle, unused devices (bool)
parm:           enable_sriov:Enable support for SR-IOV configuration.  Enabling SR-IOV on a PF typically requires support of the userspace PF driver, enabling VFs without such support may result in non-functional VFs or PF. (bool)
parm:           disable_denylist:Disable use of device denylist. Disabling the denylist allows binding to devices with known errata that may lead to exploitable stability or security issues when accessed by untrusted users. (bool)

$ modinfo vfio_virqfd
name:           vfio_virqfd
filename:       (builtin)
description:    IRQFD support for VFIO bus drivers
author:         Alex Williamson <email address hidden>
license:        GPL v2
file:           drivers/vfio/vfio_virqfd
version:        0.1

Po-Hsu Lin
Would you please fix this bug as well?