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  • Host: Ubuntu 20.04
  • Guest: Ubuntu 20.04
  • GPU: NVIDIA® GeForce® RTX 2080 Ti

Enable IOMMU

Configure GRUB

Edit /etc/default/grub

# Intel CPU
GRUB_CMDLINE_LINUX_DEFAULT="amd_iommu=on iommu=pt kvm_amd.npt=1 kvm_amd.avic=1"

Update GRUB

sudo update-grub


sudo shutdown -r now

Verify IOMMU is enabled

dmesg | grep IOMMU


IOMMU enabled

Enable IOMMU group

Check IOMMU group is enabled

for a in /sys/kernel/iommu_groups/*; do find $a -type l; done | sort --version-sort



Edit BIOS setting is not enabled

If output is not expected, configure BIOS setting



  • Advanced => System Agent Configuration => Intel VT for Directed I/O (VT-d)


Isolation of the guest GPU

graph LR subgraph C [guest] C1[PCI device] end subgraph B [hypervisor] B1[VFIO] --> C1[PCI device] end subgraph A [Host] A1[PCI device] --> B1[VFIO] end

Using vfio-pci to manage PCI device

Find out vendor ID and device ID

lspci -nn | grep -i NVIDIA

01:00.0 VGA compatible controller [0300]: NVIDIA Corporation TU102 [GeForce RTX 2080 Ti] [10de:1e04] (rev a1)
01:00.1 Audio device [0403]: NVIDIA Corporation TU102 High Definition Audio Controller [10de:10f7] (rev a1)
01:00.2 USB controller [0c03]: NVIDIA Corporation TU102 USB 3.1 Host Controller [10de:1ad6] (rev a1)
01:00.3 Serial bus controller [0c80]: NVIDIA Corporation TU102 USB Type-C UCSI Controller [10de:1ad7] (rev a1)

GeForce RTX 2080 Ti VGA compatible controller: PCI ID:01:00.0 vendor ID: 10de device ID: 1e04

Configure GRUB


Apply all the related devices

GRUB_CMDLINE_LINUX_DEFAULT="intel_iommu=on vfio-pci.ids=10de:1e04,10de:10f7,10de:1ad6,10de:1ad7"

Update GRUB

sudo update-grub


sudo reboot

Verify PCI device is managed by vfio-pci

lspci -nnv

Find the line Kernel driver in use

0b:00.0 VGA compatible controller [0300]: NVIDIA Corporation TU102 [GeForce RTX 2080 Ti] [10de:1e04] (rev a1) (prog-if 00 [VGA controller])
Kernel driver in use: vfio-pci

Test GPU passthrough on kvm instance

Fresh install

Run virt-install with --host-device [device_id] and --features kvm_hidden=on parameters

virt-install ... \
--host-device 01:00.0 \
--features kvm_hidden=on \

Modify existing instance

virsh edit [domain]

Add PCI mapping hostdev block

0000:01:00.0 within the host will be mapped to 0000:04:00.0 within guest


bus number should less than virtio's

Increase virtio's bus number to spare small number for new added entry

<hostdev mode='subsystem' type='pci' managed='yes'>
<address domain='0x0000' bus='0x01' slot='0x00'function='0x0'/>
<address type='pci' domain='0x0000' bus='0x04'slot='0x00' function='0x0'/>
<memballoon model='virtio'>
<address type='pci' domain='0x0000' bus='0x05'slot='0x00' function='0x0'/>
<rng model='virtio'>
<backend model='random'>/dev/urandom</backend>
<address type='pci' domain='0x0000' bus='0x06'slot='0x00' function='0x0'/>

kvm hidden within features block

<hidden state='on'/>

Check GPU is working in guest


04:00.0 VGA compatible controller: NVIDIA Corporation TU102[GeForce RTX 2080 Ti] (rev a1)

Install NVIDIA driver

sudo apt update
sudo apt install nvidia-driver-460
sudo reboot


Wed Mar 10 08:19:43 2021
| NVIDIA-SMI 460.39 Driver Version: 460.39 CUDVersion: 11.2 |
| GPU Name Persistence-M| Bus-Id Disp.A Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage GPU-Util Compute M. |
| | | MIG M. |
| 0 GeForce RTX 208... Off | 00000000:04:00.0 Of| N/A |
| 15% 44C P0 1W / 250W | 0MiB / 11019Mi| 0% Default |
| | | N/A |
Processes: |
| GPU GI CI PID Type Procesname GPU Memory |
| ID ID Usage |
| No running processefound |