After passthrough of integrated graphics, PVE fails to start.

[matrixchu]

After upgrading PVE from version 7 to 8, I noticed that I could select integrated graphics in the PCI options. After adding this PCI device to the Windows virtual machine and starting it, I lost access to the PVE management interface. After restarting PVE, the monitor goes black shortly after reaching the login screen. How can I recover from this?

In addition, when I enter PVE’s Linux system in emergency mode, I find that the /etc/pve directory is empty, without any directories or configuration files. I am unable to perform backups or modify virtual machine configurations. Do I need to mount an additional disk? How can I mount it?

My hardware:

CPU: AMD Athlon 3000G
software: pve 8.0.4

 

[leesteken]

After upgrading PVE from version 7 to 8, I noticed that I could select integrated graphics in the PCI options. After adding this PCI device to the Windows virtual machine and starting it, I lost access to the PVE management interface.

Probably because there are many other devices (like the network controller) in the same IOMMU group as the GPU and you cannot share devices from the same group between VMs and/or the Proxmox host.

After restarting PVE, the monitor goes black shortly after reaching the login screen. How can I recover from this?

If you did not make configuration changes to /etc/modprobe.d/, the kernel parameters, etc. Then what you describe you did should not have lasting effects.
Does your Windows VM start automatically then Proxmox boots? Then make sure it does not. Press e in the boot menu and add amd_iommu=off to the kernel parameters to prevent VMs with PCI(e) passthrough from starting, or simply disable IOMMU in the motherboard BIOS.

In addition, when I enter PVE’s Linux system in emergency mode, I find that the /etc/pve directory is empty, without any directories or configuration files. I am unable to perform backups or modify virtual machine configurations. Do I need to mount an additional disk? How can I mount it?

It's not a real filesystem but a database. The Proxmox services need to be started normally for it to be there. There is no official "emergency mode", so I'm not sure how you booted and why the services are not running. Lots of threads about this on the forum but I suggest you try the work-around for your automatically starting VM first.

 

[matrixchu]

Probably because there are many other devices (like the network controller) in the same IOMMU group as the GPU and you cannot share devices from the same group between VMs and/or the Proxmox host.

If you did not make configuration changes to /etc/modprobe.d/, the kernel parameters, etc. Then what you describe you did should not have lasting effects.
Does your Windows VM start automatically then Proxmox boots? Then make sure it does not. Press e in the boot menu and add amd_iommu=off to the kernel parameters to prevent VMs with PCI(e) passthrough from starting, or simply disable IOMMU in the motherboard BIOS.

It's not a real filesystem but a database. The Proxmox services need to be started normally for it to be there. There is no official "emergency mode", so I'm not sure how you booted and why the services are not running. Lots of threads about this on the forum but I suggest you try the work-around for your automatically starting VM first.

Thanks for your reply. I config Windows VM automatically start then Proxmox boot. I will try to set amd_iommu=off later. The emergency mode is the Debain Linux. I press e in the boot menu and add systemd.unit=emergency.target. So when I enter emergency mode, I can not find conf, so I can not disable Windows VM automatically start.
If I not enter emergency mode , the monitor goes black, ssh can not connect. I can not do anything.

 

[matrixchu]

Thanks for your reply. I config Windows VM automatically start then Proxmox boot. I will try to set amd_iommu=off later. The emergency mode is the Debain Linux. I press e in the boot menu and add systemd.unit=emergency.target. So when I enter emergency mode, I can not find conf, so I can not disable Windows VM automatically start.
If I not enter emergency mode , the monitor goes black, ssh can not connect. I can not do anything.

I try to set amd_iommu=off is successfully, thanks.