GPU passthrough fails over looking glass, worked fine without it

# delete the ISHMEM file
sudo rm /dev/shm/looking-glass

# disable the service the helper script enabled
sudo systemctl disable  lg_start.service

# remove the service 
sudo rm /etc/systemd/system/lg_start.service

# remove the script the helper script created
sudo rm /usr/bin/lg_start.sh

Apart from the folder this helper script was ran into this should be it on the host at least. The installed dependencies should not hurt, since you would require them on the next attempt to compile the client application. I have not checked if the helper script installed unneeded dependencies, tough.

P.S. Also you should learn to read bash scripts yourself.

Even more buffing to me, as it was working properly without any 43 code, before LG

The infamous code 43. Again, has nothing to do with LG. Google “VFIO code 43” to see possible remedies. The usual culprits are missing vendor_id and hidden_state attributes in your libvirt’s XML. If you have those there, try to change the vendor_id string to something else.

You can have a look here!

As i am a bit frustrated with it all, and doubt my choices of guides. Could you help me with the following:

  1. Can you provide me with your go to GPU passthrough guide
  2. How can i reverse any original passthrough changes (and start from scratch)

Thank you all for your time and help

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The granddaddy for VFIO passthrough is the ArchWiki article @H-i-v-e gave you.

Beyond that, you should visit L1Tech’s VFIO forum, and the VFIO Discord. Both (especially the Discord server) have very helpful folks that can assist you in getting VFIO working.

Please remember that this forum is for LG assistance only and assumes you have a fully functional VFIO VM.

1 Like

The go-to guide of my choice is the one I already posted. But take note that I am on Arch, so I can follow this guide verbatim. The guide is universally applicable, but you would need to understand what is happening in order to be able to make the transfer to (K)Ubuntu.

Thank you both.

I will put them to good use.

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I’ve come to the point where vm_Win11 gpu passthrough works well. Attached monitor is hardware accelerated, and Nvidia drivers are installed and work fine.

The moment i modify the xml from:

 <features>
    <acpi/>
    <apic/>
    <hyperv mode='custom'>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
    </hyperv>
    <vmport state='off'/>
  </features>

To This:

 <features>
    <acpi/>
    <apic/>
    <hyperv mode='custom'>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
      <vpindex state='on'/>
      <synic state='on'/>
      <stimer state='on'>
        <direct state='on'/>
      </stimer>
      <reset state='on'/>
      <vendor_id state='on' value='1234567890ab'/>
      <frequencies state='on'/>
      <reenlightenment state='on'/>
      <tlbflush state='on'/>
      <ipi state='on'/>
      <evmcs state='off'/>
    </hyperv>
    <kvm>
      <hidden state='on'/>
    </kvm>
    <vmport state='off'/>
    <ioapic driver='kvm'/>
  </features>

The second monitor stops working, and the Nvidia driver get error 43.

If i revert to the original xml edit, all goes back to normal.

Any suggestions?

This is not related to Looking-Glass. Please post your question in the VFIO forum or the VFIO discord.