mietzen/asmedia_1166_proxmox_passthrough.md

Guide: Setting Up ASMedia 1166 on Proxmox

To flash the controller with the correct firmware, you must have access to a Windows machine.

⚠️ Do NOT use version 241224-0000-00!

With this version, starting the VM in Proxmox will hang indefinitely. The VM start command never completes, and you're forced to hard reset the Proxmox host. This is also the version reporting 32 SATA Devices instead of 6.

Firmware

Download and flash this firmware version: 211108-0000-00 (archived version). Other might work as well, but this is the one I'm using.

My System:

AMD Ryzen Pro 5655G
GIGABYTE B550I AORUS PRO AX

Kernel Parameters

If Proxmox is installed using ZFS:

Edit /etc/kernel/cmdline and append the following parameter:

iommu=pt

If installed using LVM/ext4:

Edit /etc/default/grub and add it inside the GRUB_CMDLINE_LINUX line:

GRUB_CMDLINE_LINUX="... iommu=pt"

Check IOMMU Groups

Run the following to list your IOMMU groups:

shopt -s nullglob
for g in $(find /sys/kernel/iommu_groups/* -maxdepth 0 -type d | sort -V); do
  echo "IOMMU Group ${g##*/}:"
  for d in $g/devices/*; do
    echo -e "\t$(lspci -nns ${d##*/})"
  done
done

If your ASMedia 1166 controller shares an IOMMU group with other devices, add this parameter as well:

pcie_acs_override=downstream,multifunction

Add it to /etc/kernel/cmdline or /etc/default/grub, depending on your setup.

Load Required Modules

Edit /etc/modules and add the following lines:

vfio
vfio_iommu_type1
vfio_pci

Blacklist AHCI for ASM1166

Create /etc/modprobe.d/ahci-blacklist.conf with the following content:

options vfio-pci ids=1b21:1166
softdep ahci pre: vfio-pci

Rebuild Initramfs

Run:

update-initramfs -u -k all

Then reboot your system.

Verify the config

After reboot, run:

lspci -nnk | grep -A 3 ASM1166

You should see something like:

03:00.0 SATA controller [0106]: ASMedia Technology Inc. ASM1166 Serial ATA Controller [1b21:1166] (rev 02)
    Subsystem: ZyDAS Technology Corp. ASM1166 Serial ATA Controller [2116:2116]
    Kernel driver in use: vfio-pci
    Kernel modules: ahci

The line Kernel driver in use: vfio-pci confirms that the controller is bound correctly.

Add Device to VM

Now, you can add the ASM1166 controller to your VM under Hardware -> Add -> PCI Device in the Proxmox UI.

geobdesign · 2026-01-04T01:14:51Z

I'm new to Proxmox and trying to follow this tutorial.

I have a latest gen MSI Intel 125H NUC using M.2 to SATA ASM1166.

1 - I successfully downgraded the firmware to the recommended version.
2 - I have PVE OS installed on it's own Ext4 LVM NVMe.
3 - I want to create a ZFS RADI10 with 4x Ent. SSDs (for VMs and LXCs) using this ASM1166 M.2 to SATA card.
4 - It also looks like I do not have my ASM sharing a IOMMU group:
IOMMU Group 18: 01:00.0 SATA controller [0106]: ASMedia Technology Inc. ASM1166 Serial ATA Controller [1b21:1166] (rev 02) IOMMU Group 19:... etc

I'm new to Proxmox and only have basic Linux experience over the decades.
So unfortunately I'm confused about some of the recommended steps.
And I have been looking for YT and other posts to clear some of it up and only getting more confused.

Has any one come across a related article or YT video they can recommend that will clear up some of this?

Ideally a way to do some of this via the GUI?

So I can better view and understand what is changing?

Thank you!