cannot prepare PCI pass-through, IOMMU not present

[Homer-S]

Hello,
my Proxmox Server was running for years and always the PCI pass-through worked like a charm.
Yesterday night I did a reboot and today I recognized my fileserver (the vm with the passed through PCI) did not start.

I did a journal log but I will not be smarter with it.

May I ask you for some help please?

 

[Homer-S]

I tried it now with 5.15.30-2 and this worked
5.15.35-2 brought up all the errors ....

 

[leesteken]

Jun 11 14:38:57 srv-proxmox kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-5.15.35-2-pve root=/dev/mapper/pve-root ro quiet
I don't see the intel_iommu=on kernel parameter in that log line. That might be the problem? Can you attach your /etc/default/grub?

 

[Homer-S]

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet"
GRUB_CMDLINE_LINUX=""

 

[leesteken]

That does not look like the /etc/default/grub installed by Proxmox (on the Proxmox host) and I don't think it would work with kernel 5.15.30-2 and passthrough. Did you remove GRUB and reinstall the Debian package? Did you copy the /etc/default/grub from a Debian VM?

 

[Homer-S]

This is exactly the grub file from my proxmox host which is working with 5.15.30-2 and it is working. I do not remember that I change something in grub I just added the PCI Controller to the VM conf file.
I did not change something. As I wrote, after a reboot (probably with installing new kernel) it stopped working.