nvidia,nixos/nvidia: add datacenter drivers compatible with default cudaPkgs

For NVLink topology systems we need fabricmanager. Fabricmanager itself is
dependent on the datacenter driver set and not the regular x11 ones, it is also
tightly tied to the driver version. Furhtermore the current cudaPackages
defaults to version 11.8, which corresponds to the 520 datacenter drivers.

Future improvement should be to switch the main nvidia datacenter driver version
on the `config.cudaVersion` since these are well known from:

> https://docs.nvidia.com/deploy/cuda-compatibility/index.html#use-the-right-compat-package

This adds nixos configuration options `hardware.nvidia.datacenter.enable` and
`hardware.nvidia.datacenter.settings` (the settings configure fabricmanager)

Other interesting external links related to this commit are:

* Fabricmanager download site:
    - https://developer.download.nvidia.com/compute/cuda/redist/fabricmanager/linux-x86_64/
* Data Center drivers:
    - https://www.nvidia.com/Download/driverResults.aspx/193711/en-us/

Implementation specific details:

* Fabricmanager is added as a passthru package, similar to settings and
  presistenced.
* Adds `use{Settings,Persistenced,Fabricmanager}` with defaults to preserve x11
  expressions.
* Utilizes mkMerge to split the `hardware.nvidia` module into three comment
  delimited sections:
    1. Common
    2. X11/xorg
    3. Data Center
* Uses asserts to make the configurations mutualy exclusive.

Notes:

* Data Center Drivers are `x86_64` only.
* Reuses the `nvidia_x11` attribute in nixpkgs on enable, e.g. doesn't change it
  to `nvidia_driver` and sets that to either `nvidia_x11` or `nvidia_dc`.
* Should have a helper function which is switched on `config.cudaVersion` like
  `selectHighestVersion` but rather `selectCudaCompatibleVersion`.

1 files changed, 2 insertions, 0 deletions

diff --git a/nixos/doc/manual/release-notes/rl-2311.section.md b/nixos/doc/manual/release-notes/rl-2311.section.md
index 307aeee6020..a59dccfbc42 100644
--- a/nixos/doc/manual/release-notes/rl-2311.section.md
+++ b/nixos/doc/manual/release-notes/rl-2311.section.md
@@ -265,6 +265,8 @@ The module update takes care of the new config syntax and the data itself (user
 
 - The `cawbird` package is dropped from nixpkgs, as it got broken by the Twitter API closing down and has been abandoned upstream.
 
+- `hardware.nvidia` gained `datacenter` options for enabling NVIDIA Data Center drivers and configuration of NVLink/NVSwitch topologies through `nv-fabricmanager`.
+
 - Certificate generation via the `security.acme` now limits the concurrent number of running certificate renewals and generation jobs, to avoid spiking resource usage when processing many certificates at once. The limit defaults to *5* and can be adjusted via `maxConcurrentRenewals`. Setting it to *0* disables the limits altogether.
 
 - New `boot.bcache.enable` (default enabled) allows completely removing `bcache` mount support.