The PCIe Passthrough bug is back

Hi Wendell

My Rig:

  • Mainboard: MSI X570A PRO.

  • CPU: Ryzen 5950X

  • RAM: 128GiB @ 3200MHz

  • host GPU: AMD Radeon HD5400

  • host NVME SSD: WD Blue SN550 2TB 4x PCIe 3.0 Chipset (Linux + Extra Storage)

  • guest GPU: AMD Radeon RX 590

  • guest NVME SSD: WD Blue SN850 1TB 4x PCIe 4.0 CPU (Win10 VM)

According to this code:

for d in $(find /sys/kernel/iommu_groups/ -type l sort -n -k5 -t/); do

n=${d#*/iommu_groups/*}; n=${n%%/*}

printf 'IOMMU Group %s ' "$n"

lspci -nns "${d##*/}"

done;

From here:

Shows that IOMMU is on.

dmesg | grep pci-stub
Shows nothing so the code is either wrong or something renders it ineffective.

If you really want to read up on my journey the main post is:

It is not a tutorial yet, but I included all errors I encountered.
Is rather convoluted but it tells how I got where I am now.