Arch Linux

blakyris

Guest

[VFIO Kernel] PCI Passthrought - error opening /dev/vfio/1

Hii,

I'm trying to make a VM for playing GTA V with my GTX 970 on my Linux box usign KVM + QEMU + OVMF + PCI Passthrought using the VFIO Kernel.
I read a lot of tutorials on the arch wiki but when I try to launch the VM it says :

qemu-system-x86_64: -device vfio-pci,host=01:00.0: vfio: error opening /dev/vfio/1: Permission denied
qemu-system-x86_64: -device vfio-pci,host=01:00.0: vfio: failed to get group 1
qemu-system-x86_64: -device vfio-pci,host=01:00.0: Device initialization failed

on the ArchWiki it says :

QEMU also needs acces to VFIO files. Include every numbered file in /dev/vfio:

ls -1 /dev/vfio
___________________________________

/etc/libvirt/qemu.conf
--------------------------
...
cgroup_device_acl = [
    "/dev/null", "/dev/full", "/dev/zero",
    "/dev/random", "/dev/urandom",
    "/dev/ptmx", "/dev/kvm", "/dev/kqemu",
    "/dev/rtc","/dev/hpet", "/dev/vfio/vfio",
    "/dev/vfio/1"
]
...

But how i give access to /dev/vfio/ ?
Do I need to chmod on it ?
Is it insecure to do this ?

Thx

Last edited by blakyris (2015-10-23 06:27:55)

IlGab

Member

Registered: 2015-03-20

Posts: 2

Re: [VFIO Kernel] PCI Passthrought - error opening /dev/vfio/1

Check the group permission on /dev/vfio/1 and the group that run qemu in /etc/libvirt/qemu.conf