nixpkgs/nixos/modules/hardware/cpu/amd-sev.nix
2024-08-30 22:58:32 +02:00

80 lines
2.3 KiB
Nix

{ config, options, lib, ... }:
let
cfgSev = config.hardware.cpu.amd.sev;
cfgSevGuest = config.hardware.cpu.amd.sevGuest;
optionsFor = device: group: {
enable = lib.mkEnableOption "access to the AMD ${device} device";
user = lib.mkOption {
description = "Owner to assign to the ${device} device.";
type = lib.types.str;
default = "root";
};
group = lib.mkOption {
description = "Group to assign to the ${device} device.";
type = lib.types.str;
default = group;
};
mode = lib.mkOption {
description = "Mode to set for the ${device} device.";
type = lib.types.str;
default = "0660";
};
};
in
with lib; {
options.hardware.cpu.amd.sev = optionsFor "SEV" "sev";
options.hardware.cpu.amd.sevGuest = optionsFor "SEV guest" "sev-guest";
config = lib.mkMerge [
# /dev/sev
(lib.mkIf cfgSev.enable {
assertions = [
{
assertion = lib.hasAttr cfgSev.user config.users.users;
message = "Given user does not exist";
}
{
assertion = (cfgSev.group == options.hardware.cpu.amd.sev.group.default) || (lib.hasAttr cfgSev.group config.users.groups);
message = "Given group does not exist";
}
];
boot.extraModprobeConfig = ''
options kvm_amd sev=1
'';
users.groups = lib.optionalAttrs (cfgSev.group == options.hardware.cpu.amd.sev.group.default) {
"${cfgSev.group}" = { };
};
services.udev.extraRules = with cfgSev; ''
KERNEL=="sev", OWNER="${user}", GROUP="${group}", MODE="${mode}"
'';
})
# /dev/sev-guest
(lib.mkIf cfgSevGuest.enable {
assertions = [
{
assertion = lib.hasAttr cfgSevGuest.user config.users.users;
message = "Given user does not exist";
}
{
assertion = (cfgSevGuest.group == options.hardware.cpu.amd.sevGuest.group.default) || (lib.hasAttr cfgSevGuest.group config.users.groups);
message = "Given group does not exist";
}
];
users.groups = lib.optionalAttrs (cfgSevGuest.group == options.hardware.cpu.amd.sevGuest.group.default) {
"${cfgSevGuest.group}" = { };
};
services.udev.extraRules = with cfgSevGuest; ''
KERNEL=="sev-guest", OWNER="${user}", GROUP="${group}", MODE="${mode}"
'';
})
];
}