Dear all, in my first two messages from today, I have described how intel_iommu=on makes the AHCI / SATA driver misbehave when trying to initialize an additional PCIe SATA controller card on one of our servers, and how intel_iommu=igfx_off changed that situation. This message is to report that I can't pass through the SATA controller in question to a VM when the kernel has been booted with intel_iommu=igfx_off. Things are going wrong already during the boot process. dmesg | grep vfio says: [ 1.074239] vfio-pci: probe of 0000:02:00.0 failed with error -22 [ 1.074309] vfio_pci: add [1b4b:9128[ffff:ffff]] class 0x000000/00000000 1b4b:9128 is indeed the correct Vendor / Device ID, and it finds the device correctly (bus 2, device 0, function 0 is exactly the place where the controller resides, according to lspci after having booted without any kernel parameters). But although it finds the device, it fails when probing it (I admit that I have no clue what this means). Now I am in the following situation: - I have to turn on "some sort of" intel_iommu (otherwise, I can't use vfio at all). - intel_iommu=on would probably be the right thing, but the AHCI driver misbehaves when trying to initialize the SATA controller in question. - intel_iommu=igfx_off heals that misbehavior, but probably is the reason that vfio can't probe the device (am I right here?) Consequently, I can't pass through that controller into a virtual machine. Please refer to my first two messages from today if you would like to know the hardware and software setup and the further circumstances. As said in my previous messages, I would be glad if I could help with debugging the issues if someone could give me appropriate instructions. Thank you very much, Binarus
