Nvidia GPU passthrough error 43 Windows Server 2019

Hi everyone!

I am trying to set up a server with 2 VMs for doing graphics test workloads. One of the VMs has an AMD RX6800, the other one an Nvida RTX3080. The system has 64 core epyc CPU with about 80GB or working RAM (turns out the RAM was not officially supported so we only got 80 of the 128GB working. For the host OS I am using Ubuntu Server 20.04. I wasn’t sure what the best host OS was, but I found a guide of someone doing GPU passthrough with Ubuntu.

So far I have managed to get the VM with the AMD GPU set up all correctly and it’s working wonderfully. The only real issue I had was that I had to manually install the graphics driver via a .inf file.

Unfortunately, I have had less luck with the other VM. I first had blue screens, but fixed those by specifying the vfio driver in the grub bootloader for both the GPUs in the system (also including the audio PCI device). After that I am managed to get the GPU working with the latest driver (511.79) installed. I managed to run vkcube and vulkaninfo without issues. However, at some point the GPU will stop working and gives me an error 43 in the device manager. After rebooting the VM it will sometimes work again for a while, but it eventually errors.

From what I understand, error 43 was Nvidia blocking GPU passthrough on geforce by detecting if it was running in a VM or not. But that was unlocked almost a year ago in the driver as a ‘beta’ feature.

When googling around I can only find articles working around the error 43 by hiding the fact that it is running in a VM, but I don’t think that is related to my issue. I tried some of the workarounds, but they don’t seem to make a difference.

I was wondering, since there are a lot of people going GPU passthrough here, if anyone could help me debug this issue. I am not sure where I can even find any error information other than error 43 in windows.

Any help would be greatly appreciated.

PS For reference this is the XML of my NV VM configuration:

<domain type='kvm' id='7' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
    <libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0">
      <libosinfo:os id="http://microsoft.com/win/2k19"/>
  <memory unit='KiB'>33554432</memory>
  <currentMemory unit='KiB'>33554432</currentMemory>
  <vcpu placement='static'>62</vcpu>
    <type arch='x86_64' machine='pc-q35-4.2'>hvm</type>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
  <cpu mode='custom' match='exact' check='full'>
    <model fallback='forbid'>EPYC-Rome</model>
    <topology sockets='1' cores='31' threads='2'/>
    <feature policy='require' name='x2apic'/>
    <feature policy='require' name='tsc-deadline'/>
    <feature policy='require' name='hypervisor'/>
    <feature policy='require' name='tsc_adjust'/>
    <feature policy='require' name='spec-ctrl'/>
    <feature policy='require' name='stibp'/>
    <feature policy='require' name='arch-capabilities'/>
    <feature policy='require' name='ssbd'/>
    <feature policy='require' name='xsaves'/>
    <feature policy='require' name='cmp_legacy'/>
    <feature policy='require' name='ibrs'/>
    <feature policy='require' name='amd-ssbd'/>
    <feature policy='require' name='virt-ssbd'/>
    <feature policy='require' name='rdctl-no'/>
    <feature policy='require' name='skip-l1dfl-vmentry'/>
    <feature policy='require' name='mds-no'/>
    <feature policy='require' name='pschange-mc-no'/>
  <clock offset='localtime'>
    <timer name='rtc' tickpolicy='catchup'/>
    <timer name='pit' tickpolicy='delay'/>
    <timer name='hpet' present='no'/>
    <timer name='hypervclock' present='yes'/>
    <suspend-to-mem enabled='no'/>
    <suspend-to-disk enabled='no'/>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/home/traverse/windows_server_2019_eval.iso' index='3'/>
      <target dev='sda' bus='sata'/>
      <boot order='1'/>
      <alias name='sata0-0-0'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/home/traverse/virtio-win-0.1.215.iso' index='2'/>
      <target dev='sdb' bus='sata'/>
      <alias name='sata0-0-1'/>
      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/home/traverse/vm-disks/gronhaj-win-rtx3090.qcow2' index='1'/>
      <target dev='vdb' bus='virtio'/>
      <alias name='virtio-disk1'/>
      <address type='pci' domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
    <controller type='usb' index='0' model='qemu-xhci' ports='15'>
      <alias name='usb'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x0'/>
    <controller type='sata' index='0'>
      <alias name='ide'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
    <controller type='pci' index='0' model='pcie-root'>
      <alias name='pcie.0'/>
    <controller type='pci' index='1' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='1' port='0x10'/>
      <alias name='pci.1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0' multifunction='on'/>
    <controller type='pci' index='2' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='2' port='0x11'/>
      <alias name='pci.2'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x1'/>
    <controller type='pci' index='3' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='3' port='0x12'/>
      <alias name='pci.3'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x2'/>
    <controller type='pci' index='4' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='4' port='0x13'/>
      <alias name='pci.4'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x3'/>
    <controller type='pci' index='5' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='5' port='0x14'/>
      <alias name='pci.5'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x4'/>
    <interface type='direct'>
      <mac address='52:54:00:5c:da:cf'/>
      <source dev='bond0' mode='vepa'/>
      <target dev='macvtap1'/>
      <model type='e1000e'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
    <serial type='pty'>
      <source path='/dev/pts/2'/>
      <target type='isa-serial' port='0'>
        <model name='isa-serial'/>
      <alias name='serial0'/>
    <console type='pty' tty='/dev/pts/2'>
      <source path='/dev/pts/2'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
    <input type='tablet' bus='usb'>
      <alias name='input0'/>
      <address type='usb' bus='0' port='1'/>
    <input type='mouse' bus='ps2'>
      <alias name='input1'/>
    <input type='keyboard' bus='ps2'>
      <alias name='input2'/>
    <graphics type='vnc' port='5900' autoport='yes' listen=''>
      <listen type='address' address=''/>
      <model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1' primary='yes'/>
      <alias name='video0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <driver name='vfio'/>
        <address domain='0x0000' bus='0x81' slot='0x00' function='0x0'/>
      <alias name='hostdev0'/>
      <address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x0' multifunction='on'/>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <driver name='vfio'/>
        <address domain='0x0000' bus='0x81' slot='0x00' function='0x1'/>
      <alias name='hostdev1'/>
      <address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x1'/>
    <memballoon model='virtio'>
      <alias name='balloon0'/>
      <address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x0'/>
  <seclabel type='dynamic' model='apparmor' relabel='yes'>
  <seclabel type='dynamic' model='dac' relabel='yes'>
    <qemu:arg value='-cpu'/>
    <qemu:arg value='host,hv_time,kvm=off,hv_vendor_id=null'/>
    <qemu:arg value='-machine'/>
    <qemu:arg value='q35,kernel_irqchip=on'/>

If you’re not using a quadro or tesla, you need to hide the VM. kvm state=hidden and vendorid=c0f3c0f3 need to be set.

There may be some additional flags needed, but I haven’t played with nvidia in passthrough since I had a 1080.

I already had set kvm=off and hw_vendor_id=null. However, I can’t quite figure out what the exact settings are you mentioned.

I am also not sure if those settings are still needed since Nvidia doesn’t actively block the usage of geforce cards in a VM anymore. They call it ‘beta’ support for GPU passthrough of geforce cards.

Maybe it’s the typo in your config?

hv → hw

Oh I totally missed that! Trying it right now!

I get this error now: error: internal error: qemu unexpectedly closed the monitor: 2022-03-14T09:20:14.757373Z qemu-system-x86_64: can't apply global host-x86_64-cpu.hw-vendor-id=null: Property '.hw-vendor-id' not found

According to a post I can’t link, it’s supposed to be hv_vendor_id

I’m headed to bed, but I guess I’m curious what version of things you’re running? I don’t remember what version of qemu it was, but at some point I remember changing my XML file and removing all of the qemu args at the bottom and into other parts of the file. See → Arch Wiki

Plus, not sure if the cpu arg should be used for those options? …but I honestly don’t know :person_shrugging:

Here’s my <feature/>, as an example:


Good luck!

1 Like

Qemu version

[email protected]:~$ /usr/bin/qemu-system-x86_64 --version
QEMU emulator version 4.2.1 (Debian 1:4.2-3ubuntu6.21)
Copyright (c) 2003-2019 Fabrice Bellard and the QEMU Project developers

I’ll go try out the settings you posted and the guide you linked!

Thanks ^.^

… really off to bed this time… I’m running a much newer version so ymmv!!

λ ~ → qemu-system-x86_64 --version
QEMU emulator version 6.2.0
Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers

Oh that’s good to know!
Have a good night!

So I found out that it was failing to reserve address space for the bar. Thanks to the posted guide I found out that I needed to add video=vesafb:off,efifb:off to the GRUB_CMDLINE_LINUX_DEFAULT variable. That way the host OS really doesn’t use the NV GPU (even though I already passed the hardware IDs to vfio-pci.ids.

That solved my error 43 problem, but it’s still not quite as smoothly as I was hoping. It keeps resetting the graphics driver in windows with this message Display driver nvlddmkm stopped responding and has successfully recovered.. I am not sure what causes this so I am currently investigating that.

1 Like

I managed to get the VM running for a while, running vkcube for a couple of hours. Then I tried to resize my remote desktop screen, at which point the entire machine crashed and rebooted. I now get error 43 again, so I am probably missing another setting. I don’t think it’s NV blocking anything though, just a bad config.

I’ll keep this thread updated with my findings.