libvirt.libvirtError: internal error: libxenlight failed to attach pci device 0000:04:00.0

[tempmail]

If it runs with let’s say 1848MB RAM, after that you want to patch xen.xml and related:

Quick howto: GPU passthrough with lots of RAM

Users in this community have had a difficult time with GPU passthrough over the years. I want to share a quick recipe for how I got mine working. Motherboard chipset: Intel z790 CPU: Intel Raptor Lake series GPU: NVIDIA RTX 4090 (24GB VRAM) QubesOS version: 4.1.2 (R4.1) I followed the guide by @neowutran . However, like others, I couldn’t run the GPU VM with more than a few GB of memory. The trick was to set the max-ram-below-4g variable to 2G instead of 3.5G. I now have a VM with a 409…