Blacklist the nouveau driver on EC2

nixos/modules/virtualisation/amazon-image.nix

@@ -91,6 +91,10 @@ in
     boot.initrd.kernelModules = [ "xen-blkfront" ];
     boot.kernelModules = [ "xen-netfront" ];
 
+    # Prevent the nouveau kernel module from being loaded, as it
+    # interferes with the nvidia/nvidia-uvm modules needed for CUDA.
+    boot.blacklistedKernelModules = [ "nouveau" ];
+
     # Generate a GRUB menu.  Amazon's pv-grub uses this to boot our kernel/initrd.
     boot.loader.grub.version = if cfg.hvm then 2 else 1;
     boot.loader.grub.device = if cfg.hvm then "/dev/xvda" else "nodev";