Thanks! I took a look at my IOMMU settings and did not disable them but enabled passthrough by default:
# CONFIG_CALGARY_IOMMU is not set
CONFIG_IOMMU_IOVA=y
CONFIG_IOMMU_API=y
CONFIG_IOMMU_SUPPORT=y
# Generic IOMMU Pagetable Support
# end of Generic IOMMU Pagetable Support
# CONFIG_IOMMU_DEBUGFS is not set
CONFIG_IOMMU_DEFAULT_PASSTHROUGH=y
CONFIG_OF_IOMMU=y
# CONFIG_AMD_IOMMU is not set
CONFIG_INTEL_IOMMU=y
# CONFIG_INTEL_IOMMU_SVM is not set
CONFIG_INTEL_IOMMU_DEFAULT_ON=y
CONFIG_INTEL_IOMMU_FLOPPY_WA=y
and the error:
NVRM: GPU 0000:01:00.0: Failed to copy vbios to system memory.
NVRM: GPU 0000:01:00.0: RmInitAdapter failed! (0x30:0xffff:755)
NVRM: GPU 0000:01:00.0: rm_init_adapter failed, device minor number 0
went away. Now CUDA works, the only thing is that there is no display output through the nvidia card yet. I don’t have any custom xorg configuration file. I tried disabling IOMMU but the problem still persists (no display output). I also tried several permutations of framebuffer support (EFI on/off, nvidia support on/off mark vgs/vbe/efi FB as generic on/off) to no avail. Of course I also switched default display device at my motherboard BIOS.