1. Go to OpenWRT release page, select the latest release stable release, then targets -> x86 -> 64. Right-click generic-ext4-combined.img.gz (not the "efi"!) and copy the link.

2. On the Proxmox host, download the archive and unpack it:

wget *paste link here*
gunzip openwrt-*.img.gz

3. Resize the image to be the size you want your VM's disk to be (example with 8 GiB):

qemu-img resize -f raw openwrt-*.img 8G

4. Create a new VM in Proxmox. Make sure to use:

• No installation media
• SeaBIOS
• No drives

Do not start the VM yet.

5. Import the resized OpenWRT image into the new VM (replace VMID and STORAGEID with yours):

qm importdisk VMID openwrt-*.img STORAGEID

6. Go to the VM -> Hardware, select the newly imported disk named "Unused Disk 0", press "Edit", set it to VirtIO with "Discard" and "IO Thread" enabled, then press OK.

7. Go to the VM -> Options -> Boot Order, make sure that virtio0 is at the top and is the only one that is ticked.

8. Add whatever networking or other devices you need.

9. You're done! Start the VM and enjoy all the routing.