From e40595797825e70b16e01c848692fe09c21eb92b Mon Sep 17 00:00:00 2001
From: Artemis Tosini <me@artem.ist>
Date: Tue, 1 Feb 2022 06:59:17 +0000
Subject: [PATCH] Add vfio on starlight

---
 system/starlight/default.nix |  1 +
 system/starlight/vfio.nix    | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 system/starlight/vfio.nix

diff --git a/system/starlight/default.nix b/system/starlight/default.nix
index b8a0a7c..d4976da 100644
--- a/system/starlight/default.nix
+++ b/system/starlight/default.nix
@@ -5,6 +5,7 @@
     ./boot-config.nix
     ./hardware-configuration.nix
     ./scripts.nix
+    ./vfio.nix
     ../../sets/builder.nix
     ../../sets/cpu/amd.nix
     ../../sets/fpga.nix
diff --git a/system/starlight/vfio.nix b/system/starlight/vfio.nix
new file mode 100644
index 0000000..0f2fb2f
--- /dev/null
+++ b/system/starlight/vfio.nix
@@ -0,0 +1,34 @@
+{ pkgs, pkgs-unstable, ... }:
+
+# based on https://alexbakker.me/post/nixos-pci-passthrough-qemu-vfio.html
+{
+  environment.systemPackages = [
+    pkgs-unstable.looking-glass-client
+    pkgs.scream
+  ];
+
+  boot.initrd = {
+    availableKernelModules = [ "amdgpu" "vfio-pci" ];
+    preDeviceCommands = ''
+      echo vfio-pci > /sys/bus/pci/devices/0000:0b:00.0/driver_override
+      echo vfio-pci > /sys/bus/pci/devices/0000:0b:00.1/driver_override
+      modprobe -i vfio-pci
+    '';
+  };
+
+  systemd.tmpfiles.rules = [
+    "f /dev/shm/scream 0660 artemis qemu-libvirtd -"
+    "f /dev/shm/looking-glass 0660 artemis qemu-libvirtd -"
+  ];
+
+  systemd.user.services.scream-ivshmem = {
+    enable = true;
+    description = "Scream IVSHMEM";
+    serviceConfig = {
+      ExecStart = "${pkgs.scream}/bin/scream -m /dev/shm/scream -o pulse";
+      Restart = "always";
+    };
+    wantedBy = [ "multi-user.target" ];
+    requires = [ "pulseaudio.service" ];
+  };
+}