This is an FYI but nvidia drivers do not work when AMD Secure Memory Encryption is enabled in the kernel. The only relevant message in dmesg is this one : nvidia 0000:41:00.0: SME is active, device will require DMA bounce buffers Kernel configuration to disable: Processor type and features --> CONFIG_AMD_MEM_ENCRYPT Tested against 4.14.31/32 but is probably the same on 14.15.x This feature was introduced in 4.14.x as far as I understand, so not a problem before this version. Maybe worth adding it to the wiki.
What doesn't work when AMD Secure Memory Encryption is enabled?
The kernel modules load properly, but when starting sddm I get a blank screen.
My bad, the nvidia modules do not initialize properly at all, I missed the logs earlier # dmesg [ 31.630667] nvidia 0000:41:00.0: SME is active, device will require DMA bounce buffers [ 31.832968] NVRM: RmInitAdapter failed! (0x24:0x1e:1087) [ 31.832991] NVRM: rm_init_adapter failed for device bearing minor number 0 Xorg.0.log [ 44.433] (**) NVIDIA(0): Depth 24, (--) framebuffer bpp 32 [ 44.433] (==) NVIDIA(0): RGB weight 888 [ 44.433] (==) NVIDIA(0): Default visual is TrueColor [ 44.433] (==) NVIDIA(0): Using gamma correction (1.0, 1.0, 1.0) [ 44.433] (**) NVIDIA(0): Enabling 2D acceleration [ 44.650] (EE) NVIDIA(GPU-0): Failed to initialize the NVIDIA GPU at PCI:65:0:0. Please [ 44.650] (EE) NVIDIA(GPU-0): check your system's kernel log for additional error [ 44.650] (EE) NVIDIA(GPU-0): messages and refer to Chapter 8: Common Problems in the [ 44.650] (EE) NVIDIA(GPU-0): README for additional information. [ 44.650] (EE) NVIDIA(GPU-0): Failed to initialize the NVIDIA graphics device! [ 44.650] (EE) NVIDIA(0): Failing initialization of X screen 0 By the way this was tested against sys-kernel/gentoo-sources-4.15.15 Again, disabling CONFIG_AMD_MEM_ENCRYPT makes things work again.
Update for kernel 4.18.5 (at the time of this writing this is a supposedly a supported kernel version by NVidia) The nvidia drivers now works when CONFIG_AMD_MEM_ENCRYPT is enabled, but not if SME is enabled by default, with CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT. Which is roughly the same to say that it does not work with SME. Same error messages.
Same here, Gentoo Linux amd64, AMD Ryzen 5 2600X, NVIDIA RTX 2060 Super. Errors in Xorg.0.log when starting X: (EE) NVIDIA(GPU-0): Failed to initialize DMA (EE) NVIDIA(0): Failed to allocate push buffer Tested with gentoo-sources 5.4.48 and nvidia-drivers 450.57. It would seem NVIDIA has been aware of this bug for quite a while, but is either unable or unwilling to fix it: https://forums.developer.nvidia.com/t/unable-to-start-x-failed-to-initialize-dma/64925/12
It would seem this is not going to be fixed anytime soon. This is the reply I now got from NVIDIA after opening a bug back in February: AMD SME is not supported in NVIDIA Linux driver. Driver README calls out that user needs to disable SME : [https://download.nvidia.com/XFree86/Linux-x86_64/450.57/README/dma_issues.html] Engineering team is currently evaluating multiple options to support this feature in future, however we can not commit any timeline for it at this moment.
I don't think there's much that can be done here about this. At best could add a kernel config check for CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT To at least discourage users from using it (can't check for merely enabled as this is a default in gentoo-kernel{,-bin}).
