PCIe Passthrough in Proxmox VE

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This guide explains how to configure PCIe passthrough in Proxmox VE using any PCIe device — such as a GPU, USB controller, or network card. As an example, we use an NVIDIA RTX 4080 Super. You will learn how to enable IOMMU, bind the device to VFIO, and attach it to a virtual machine.

Requirements

Proxmox VE 7.x or 8.x
A PCIe device (example: RTX 4080 Super)
Virtualization (VT-d / AMD-Vi) enabled in BIOS/UEFI

Video Guide

Step 1 – Enable IOMMU in GRUB

IOMMU (Input-Output Memory Management Unit) allows Proxmox to assign PCIe devices directly to virtual machines. Enable it in the GRUB bootloader:

nano /etc/default/grub

Find the line starting with GRUB_CMDLINE_LINUX_DEFAULT and modify it based on your CPU:

Intel:

GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_iommu=on iommu=pt"

AMD:

GRUB_CMDLINE_LINUX_DEFAULT="quiet amd_iommu=on iommu=pt"

Save with CTRL+O, exit with CTRL+X, then apply the changes:

update-grub

Step 2 – Load VFIO Kernel Modules

VFIO (Virtual Function I/O) handles PCIe passthrough in a safe and isolated way.

nano /etc/modules

Add these lines at the end of the file:

vfio
vfio_iommu_type1
vfio_pci
vfio_virqfd

Save and exit.

Step 3 – Blacklist Host Drivers

Prevent Proxmox from loading drivers for the PCIe device. This is especially important for GPUs:

nano /etc/modprobe.d/blacklist.conf

Add:

blacklist nouveau
blacklist nvidia
blacklist nvidiafb
blacklist nvidia_drm

This stops Proxmox from using the GPU itself, making it available to the VM.

Step 4 – Bind PCIe Device to VFIO

List your PCI devices to find the ID of your GPU or other device:

lspci -nn

Look for vendor and product IDs, for example:

10de:2704, 10de:22bb

Create a VFIO config file:

nano /etc/modprobe.d/vfio.conf

Add this line using your device IDs:

options vfio-pci ids=10de:2704,10de:22bb

Apply the changes:

update-initramfs -u

Step 5 – Reboot

Restart your Proxmox host to apply all changes:

reboot

Step 6 – Verify VFIO Binding

After rebooting, confirm that your device is now using the vfio-pci driver:

lspci -k

Step 7 – Add PCIe Device to VM

Open the VM config file (replace <vmid> with your VM ID):

nano /etc/pve/qemu-server/<vmid>.conf

Add these lines (replace 01:00.0 and 01:00.1 with your actual device addresses):

hostpci0: 01:00.0,pcie=1,x-vga=1
hostpci1: 01:00.1

Start the VM — your PCIe device is now passed through and available directly to the virtual machine.