nixpkgs/nixos/modules/virtualisation/kvmgt.nix
pennae 8f8e101527 nixos/*: normalize <package> to <literal>
this renders the same in the manpage and a little more clearly in the
html manual. in the manpage there continues to be no distinction from
regular text, the html manual gets code-type markup (which was probably
the intention for most of these uses anyway).
2022-08-19 22:40:58 +02:00

87 lines
2.9 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.virtualisation.kvmgt;
kernelPackages = config.boot.kernelPackages;
vgpuOptions = {
uuid = mkOption {
type = with types; listOf str;
description = "UUID(s) of VGPU device. You can generate one with <literal>libossp_uuid</literal>.";
};
};
in {
options = {
virtualisation.kvmgt = {
enable = mkEnableOption ''
KVMGT (iGVT-g) VGPU support. Allows Qemu/KVM guests to share host's Intel integrated graphics card.
Currently only one graphical device can be shared. To allow users to access the device without root add them
to the kvm group: <literal>users.extraUsers.&lt;yourusername&gt;.extraGroups = [ "kvm" ];</literal>
'';
# multi GPU support is under the question
device = mkOption {
type = types.str;
default = "0000:00:02.0";
description = lib.mdDoc "PCI ID of graphics card. You can figure it with {command}`ls /sys/class/mdev_bus`.";
};
vgpus = mkOption {
default = {};
type = with types; attrsOf (submodule [ { options = vgpuOptions; } ]);
description = ''
Virtual GPUs to be used in Qemu. You can find devices via <command>ls /sys/bus/pci/devices/*/mdev_supported_types</command>
and find info about device via <command>cat /sys/bus/pci/devices/*/mdev_supported_types/i915-GVTg_V5_4/description</command>
'';
example = {
i915-GVTg_V5_8.uuid = [ "a297db4a-f4c2-11e6-90f6-d3b88d6c9525" ];
};
};
};
};
config = mkIf cfg.enable {
assertions = singleton {
assertion = versionAtLeast kernelPackages.kernel.version "4.16";
message = "KVMGT is not properly supported for kernels older than 4.16";
};
boot.kernelModules = [ "kvmgt" ];
boot.kernelParams = [ "i915.enable_gvt=1" ];
services.udev.extraRules = ''
SUBSYSTEM=="vfio", OWNER="root", GROUP="kvm"
'';
systemd = let
vgpus = listToAttrs (flatten (mapAttrsToList
(mdev: opt: map (id: nameValuePair "kvmgt-${id}" { inherit mdev; uuid = id; }) opt.uuid)
cfg.vgpus));
in {
paths = mapAttrs (_: opt:
{
description = "KVMGT VGPU ${opt.uuid} path";
wantedBy = [ "multi-user.target" ];
pathConfig = {
PathExists = "/sys/bus/pci/devices/${cfg.device}/mdev_supported_types/${opt.mdev}/create";
};
}) vgpus;
services = mapAttrs (_: opt:
{
description = "KVMGT VGPU ${opt.uuid}";
serviceConfig = {
Type = "oneshot";
RemainAfterExit = true;
ExecStart = "${pkgs.runtimeShell} -c 'echo ${opt.uuid} > /sys/bus/pci/devices/${cfg.device}/mdev_supported_types/${opt.mdev}/create'";
ExecStop = "${pkgs.runtimeShell} -c 'echo 1 > /sys/bus/pci/devices/${cfg.device}/${opt.uuid}/remove'";
};
}) vgpus;
};
};
meta.maintainers = with maintainers; [ patryk27 ];
}