Hello, I need help & I would appreciate any help to get my setup working. When I try to start a domU on Arch/Xen, I am getting the following error: xl create w7.cfg Parsing config from w7.cfg libxl: error: libxl_pci.c:1235:libxl__device_pci_add: PCI device 0:1:0.0 is not assignable libxl: error: libxl_create.c:1566:domcreate_attach_pci: libxl_device_pci_add failed: -3 libxl: error: libxl.c:1583:libxl__destroy_domid: non-existant domain 2 libxl: error: libxl.c:1542:domain_destroy_callback: unable to destroy guest with domid 2 libxl: error: libxl.c:1471:domain_destroy_cb: destruction of domain 2 failed Checking the GPU with lspci, I get: 01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GF108M [GeForce GT 525M] [10de:0df5] (rev a1) Subsystem: Dell Device [1028:0446] Kernel driver in use: nouveau Kernel modules: nouveau Background... I am relatively new to Arch and Xen (coming from Fedora and KVM) but I decided to see if Xen on Arch would support GPU passthrough for my Dell XPS 15z. It has Nvidia GeForce GT 525M. On Fedora/KVM, GPU passthrough works but there is the nasty error code 43. So that proved that the GPU can be passed through. I am trying Xen to see if the HVM will hide whatever it is that Nvidia uses to identify a VM platform and then disable drivers, giving error code 43. I have successfully installed xen and created a test VM. The config is as follows: name = 'w7' builder = 'hvm' vcpus = '2' memory = '2048' boot = 'd' on_poweroff = 'destroy' on_reboot = 'restart' on_crash = 'destroy' device_model_version = 'qemu-xen-traditional' disk = [ '/home/tim/Downloads/w7.iso,,hdc,cdrom', '/home/tim/vms/w7/w7.img,raw,hda,rw' ] vif = ['mac=00:16:3e:54:86:18,bridge=xenbr0'] acpi = '1' apic = '1' serial = 'pty' localtime = 1 # Keyboard and mouse passthrough usb = '1' usbdevice = ['tablet'] # VGA and sound passthrough viridian = '1' xen_platform_pci = '1' gfx_passthru = '1' pci_permissive = '1' pci = ['01:00.0,rdm_policy=relaxed'] # Remote vnc access vnc = '1' # vnclisten = 'x.x.x.x' The BDF of the GPU is 01:00.0 and it is what I have set for the pci parameter. I have also set intel_iommu=on in my /etc/default/grub file. I am booting the Xen kernel. I have also set the vfio-pci id for the GPU in /etc/modprobe.d/vfio.conf as: options vfio--pci ids=10de:0df5 After that, I set the vfio modules to load first in /etc/mkinitcpio.conf as follows: MODULES="vfio vfio_iommu_type1 vfio_pci vfio_virqfd i915 nouveau" HOOKS="base udev autodetect modconf block filesystems keyboard fsck" After that, I did: mkinitcpio -p linux grub-mkconfig -o /boot/grb/grub.cfg reboot After reboot, I ran the following checks: dmesg | grep vfio [ 3.856580] vfio-pci: probe of 0000:01:00.0 failed with error -22 [ 3.856584] vfio_pci: add [10de:0df5[ffff:ffff]] class 0x000000/00000000 [ 18.960859] xen_pciback xen_netback xenfs xen_privcmd xen_blkback xen_gntalloc xen_gntdev xen_evtchn ip_tables x_tables ext4 crc16 jbd2 fscrypto mbcache sd_mod serio_raw atkbd libps2 ahci libahci xhci_pci xhci_hcd libata ehci_pci ehci_hcd scsi_mod usbcore usb_common i8042 serio nouveau mxm_wmi wmi ttm i915 video button intel_gtt i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio dmesg | egrep -i iommu [ 0.000000] Command line: /boot/vmlinuz-linux root=UUID=d8ee1f55-14c6-4401-bc22-24b78eaf8863 rw intel_iommu=on quiet console=tty0 [ 0.000000] Kernel command line: /boot/vmlinuz-linux root=UUID=d8ee1f55-14c6-4401-bc22-24b78eaf8863 rw intel_iommu=on quiet console=tty0 [ 0.000000] DMAR: IOMMU enabled [ 18.960859] xen_pciback xen_netback xenfs xen_privcmd xen_blkback xen_gntalloc xen_gntdev xen_evtchn ip_tables x_tables ext4 crc16 jbd2 fscrypto mbcache sd_mod serio_raw atkbd libps2 ahci libahci xhci_pci xhci_hcd libata ehci_pci ehci_hcd scsi_mod usbcore usb_common i8042 serio nouveau mxm_wmi wmi ttm i915 video button intel_gtt i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio Is it possible that the root of the problem might the vfio-pci error -22 at boot? Thanks