You found that you are using systemd, adding bits to GRUB will not work. Instead, follow these steps:
Open the /etc/kernel/cmdline file for editing:
nano /etc/kernel/cmdline
Add the following line for AMD CPUs:
root=ZFS=rpool/ROOT/pve-1 boot=zfs amd_iommu=on iommu=pt pcie_acs_override=downstream,multifunction
note: For intel, just replace amd
with intel
, like so: intel_iommu=on
After editing the /etc/kernel/cmdline
file, refresh the boot tool by running:
proxmox-boot-tool refresh
With these steps, you should have successfully enabled IOMMU and ACS patch using systemd for your Proxmox installation.
If anyone wants to make sure if systemd is indeed used, check Proxmox VE Administration Guide