PCI Passthrough

[Kaiz]

Hi All

I installed Proxmox yesterday to test the PCI Passthrough of one of my PCI Cards. The PCI card is really old and I require it to work a Software on Windows XP. I know it seems weird to use such an old system but I require it for some testing. I managed to install proxmox and get XP working as well. I went through the PCI passthrough documentation and enabled iommu and followed all the required steps in the article. Now the issue I am facing is with passing through this particular PCI card. When I attach the PCI card and start the VM I am getting the following error;

Error: Failed to run vncproxy
Error: start failed. QEMU exited with code 1

Please note: If I attached another PCI card and start the VM, I do not get an error and the VM starts up.

The PCI card I am trying to passthrough works just fine on the physical machine. So its not the card and its not the PCI port on the board as I can see the card in the proxmox web interface and also using the command "lspci" on the shell.

Any help or suggestion would be highly appreciated.

Thank you

 

[oguz]

When I attach the PCI card and start the VM I am getting the following error;

Error: Failed to run vncproxy
Error: start failed. QEMU exited with code 1

that means the VM didn't start (Error: Failed to run vncproxy isn't very telling, but it's because the VM isn't running at all)

he PCI card I am trying to passthrough works just fine on the physical machine. So its not the card and its not the PCI port on the board as I can see the card in the proxmox web interface and also using the command "lspci" on the shell.

if you want to passthrough the device to your VM, you'll have to blacklist the kernel module on the host first.

in any case you should post the output of the following commands:
* pveversion -v
* qm config VMID (VMID is your VM, f.e. 123)
* lspci -nnk will tell you which kernel module is loaded for the device

then you can add that in the blacklist (replace FOO with the actual module after you've identified it):

echo "blacklist FOO" >> /etc/modprobe.d/blacklist.conf

and reboot the machine.

 

[leesteken]

Often PCI and even PCIe card just don't reset properly and don't work with passthrough. This is also not a common use case and vendors don't support or test for it.
It might help if you tell use which PCI card you are trying to passthrough: show the output of sudo lspci -vvvns <PCI-ID>. It will also help if you show us the VM configuration file from the /etc/pve/qemu-server./ directory. Do you happen to know about people on the internet that have successfully passed trough this particular PCI device? Can you show us your IOMMU groups and confirm that the device is alone in its own group (without using pcie_acs_override)?

 

[Kaiz]

that means the VM didn't start (Error: Failed to run vncproxy isn't very telling, but it's because the VM isn't running at all)


if you want to passthrough the device to your VM, you'll have to blacklist the kernel module on the host first.

in any case you should post the output of the following commands:
* pveversion -v
* qm config VMID (VMID is your VM, f.e. 123)
* lspci -nnk will tell you which kernel module is loaded for the device

then you can add that in the blacklist (replace FOO with the actual module after you've identified it):

echo "blacklist FOO" >> /etc/modprobe.d/blacklist.conf

and reboot the machine.

Some cards have kernel module mentioned with the PCI device and some modules just have kernel driver.

 

[Kaiz]

Often PCI and even PCIe card just don't reset properly and don't work with passthrough. This is also not a common use case and vendors don't support or test for it.
It might help if you tell use which PCI card you are trying to passthrough: show the output of sudo lspci -vvvns <PCI-ID>. It will also help if you show us the VM configuration file from the /etc/pve/qemu-server./ directory. Do you happen to know about people on the internet that have successfully passed trough this particular PCI device? Can you show us your IOMMU groups and confirm that the device is alone in its own group (without using pcie_acs_override)?

I tried looking online but could not find anyone that uses this card

 

[leesteken]

Some cards have kernel module mentioned with the PCI device and some modules just have kernel driver.

Are you unable to run the commands from post #2 or do you not want to share the output?