Hi ppl, hopefully this is fairly simple.
I’m following Oracle’s instructions to enable PCi-passthrough in VirtualBox. Manjaro Linux is my host. I’ve enabled the IOMMU in the EFI, and dmesg | grep IOMMU returns the following:
[ 0.802843] pci 0000:00:00.2: AMD-Vi: IOMMU performance counters supported
[ 0.810763] pci 0000:00:00.2: AMD-Vi: Found IOMMU cap 0x40
[ 0.811802] perf/amd_iommu: Detected AMD IOMMU #0 (2 banks, 4 counters/bank).
[ 0.844318] AMD-Vi: AMD IOMMUv2 driver by Joerg Roedel jroedel@suse.de
[ 4.249136] snd_emu10k1 0000:05:00.0: non-passthrough IOMMU detected, widening DMA allocations
well that last line doesn’t seem promising, but the instructions wanted me to make another check anyway so I continue with that. it says to search for DMAR and PCI-DMA in the kernel boot log, to check that the kernel “recognizes and uses” the IOMMU unit. dmesg | grep DMAR and dmesg | grep PCI-DMA both return nothing, cementing the concerns.
so now the issue: the instructions say the boot option “intel_iommu=on” may be necessary. I have a couple questions about that:
- Is /etc/default/grub the correct file to edit for this?
- Do I add the line anywhere in the file?
- is “intel_iommu=on” still the correct option if I’m using an AMD motherboard?
I’m running kernel 5.4.89-1 if that’s relevant.
Thank you!