GPU passthrough

https://gist.github.com/SimonTod/72945457c4d7e741a382ba9ce9c4731b

echo "blacklist nouveau" >> /etc/modprobe.d/blacklist.conf
echo "blacklist nvidia" >> /etc/modprobe.d/blacklist.conf
update-initramfs -u

lcpci
26:00.0 VGA compatible controller: NVIDIA Corporation GT218 [GeForce 210] (rev a2)
 
lspci -n -s 26:00.0
26:00.0 0300: 10de:0a65 (rev a2)
 
echo "options vfio-pci ids=10de:0a65" > /etc/modprobe.d/vfio.conf
 
rmmod vfio-pci
modprobe vfio-pci
 
dmesg
[536167.737504] vfio-pci 0000:26:00.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem
[536170.155565] vfio-pci 0000:26:00.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem
[536170.173544] vfio_pci: add [10de:0a65[ffffffff:ffffffff]] class 0x000000/00000000

It is generic error code. Possible reasons:

Problem with NVidia card GT218. Device detected under Windows 10, driver installed automatically, but device is not working. Error code 43.

Nvidia drivers detects KVM. KVM can be hidden for guest OS:

/etc/pve/qemu-server/702.conf

cpu: host,hidden=1

NOTE: Proxmox already contains fixes for Nvidia, so it is not needed.

Lots of errors on host dmesg:

vfio-pci 0000:26:00.0: BAR 3: can't reserve [mem 0xf0000000-0xf1ffffff 64bit pref]
...
pcieport 0000:00:03.1: AER: Multiple Uncorrected (Non-Fatal) error received: 0000:26:00.0
pcieport 0000:00:03.1: AER: Multiple Uncorrected (Non-Fatal) error received: 0000:26:00.0
pcieport 0000:00:03.1: AER: Multiple Uncorrected (Non-Fatal) error received: 0000:26:00.0

GPU was used as host main adapter in graphic mode. To fix it add following kernel arguments:

nomodeset textonly video=vesafb:off video=efifb:off

GRUB_CMDLINE_LINUX_DEFAULT="nomodeset textonly video=vesafb:off video=efifb:off"

root=ZFS=rpool/ROOT/pve-1 boot=zfs rootdelay=4 mitigations=off panic=30 nomodeset textonly video=vesafb:off video=efifb:off

update-grub
pve-efiboot-tool refresh

Solution was to select “Primary GPU” on PCI Device (x-vga=1 option in Proxmox config file)