From 7ea1e6ae16d019273e1b934260bb28d892eadaba Mon Sep 17 00:00:00 2001
From: Ryan Yin <xiaoyin_c@qq.com>
Date: Sun, 8 Mar 2026 00:50:43 +0800
Subject: [PATCH] feat: idols-akane - add virtfs file sharing between host &
 guest

---
 hosts/idols-akane/default.nix |  3 +++
 hosts/idols-akane/virtfs.nix  | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 hosts/idols-akane/virtfs.nix

diff --git a/hosts/idols-akane/default.nix b/hosts/idols-akane/default.nix
index e3607de1..cdcb329c 100644
--- a/hosts/idols-akane/default.nix
+++ b/hosts/idols-akane/default.nix
@@ -27,6 +27,9 @@ in
     "fat"
     "vfat"
     "exfat"
+
+    # for file sharing between host & guests
+    "virtiofs"
   ];
 
   boot.initrd.availableKernelModules = [
diff --git a/hosts/idols-akane/virtfs.nix b/hosts/idols-akane/virtfs.nix
new file mode 100644
index 00000000..6da0d91f
--- /dev/null
+++ b/hosts/idols-akane/virtfs.nix
@@ -0,0 +1,18 @@
+{
+  fileSystems."/mnt/utm" = {
+    device = "share"; # 9p tag name from UTM/QEMU configuration
+    fsType = "9p"; # Virtio-9p filesystem type
+    options = [
+      "trans=virtio" # Use virtio transport for paravirtualized I/O
+      "version=9p2000.L" # 9P protocol version (best Linux compatibility)
+      "ro" # Read-only access
+      "_netdev" # Mark as network-dependent (waits for network)
+      "nofail" # Don't fail boot if mount fails
+      "auto" # Mount automatically with -a
+
+      # Ownership mapping - all files appear as specified user/group
+      "uid=1000" # Map to user ID 1000
+      "gid=1000" # Map to group ID 100
+    ];
+  };
+}