From 8d68e1daf9a406b6bdc9fe4578d7fd8306d39f16 Mon Sep 17 00:00:00 2001
From: Joshua Bell <abc@joshuabell.xyz>
Date: Mon, 26 Jan 2026 10:21:23 -0600
Subject: [PATCH] Source system and user qvm.conf; add memory/cpus options; fix
 flake path

---
 bin/qvm-rebuild |  6 +++---
 bin/qvm-start   |  9 +++++++++
 flake.nix       | 24 ++++++++++++++++++++++++
 lib/common.sh   |  1 +
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/bin/qvm-rebuild b/bin/qvm-rebuild
index 9c67366..edea1f0 100755
--- a/bin/qvm-rebuild
+++ b/bin/qvm-rebuild
@@ -32,9 +32,9 @@ ensure_user_flake() {
     # In development: $(dirname "$0")/../flake/default-vm/
     local default_flake_dir
     
-    # Try installed location first
-    if [[ -d "$QVM_LIB_DIR/../share/qvm/default-vm" ]]; then
-        default_flake_dir="$QVM_LIB_DIR/../share/qvm/default-vm"
+    # Try installed location first ($QVM_LIB_DIR is $out/lib/qvm)
+    if [[ -d "$QVM_LIB_DIR/../../share/qvm/default-vm" ]]; then
+        default_flake_dir="$QVM_LIB_DIR/../../share/qvm/default-vm"
     else
         # Fall back to development location
         default_flake_dir="$(dirname "$(readlink -f "$0")")/../flake/default-vm"
diff --git a/bin/qvm-start b/bin/qvm-start
index 0f0b702..0a5b712 100755
--- a/bin/qvm-start
+++ b/bin/qvm-start
@@ -116,6 +116,15 @@ main() {
     # First-run initialization
     ensure_dirs
     
+    # Source config file if it exists (sets QVM_MEMORY, QVM_CPUS, etc.)
+    # Check system-wide config first, then user config (user overrides system)
+    if [[ -f "/etc/xdg/qvm/qvm.conf" ]]; then
+        source "/etc/xdg/qvm/qvm.conf"
+    fi
+    if [[ -f "$QVM_CONFIG_FILE" ]]; then
+        source "$QVM_CONFIG_FILE"
+    fi
+    
     # Check if VM runner exists, build if not
     if [[ ! -L "$QVM_VM_RUNNER" || ! -f "$(readlink -f "$QVM_VM_RUNNER" 2>/dev/null || echo "")" ]]; then
         log_info "First run detected - building VM..."
diff --git a/flake.nix b/flake.nix
index 9f7cecb..880e023 100644
--- a/flake.nix
+++ b/flake.nix
@@ -15,12 +15,36 @@
     {
       nixosModules.default =
         {
+          config,
+          lib,
           pkgs,
           ...
         }:
+        let
+          cfg = config.programs.qvm;
+        in
         {
+          options.programs.qvm = {
+            memory = lib.mkOption {
+              type = lib.types.str;
+              default = "8G";
+              description = "Amount of memory to allocate to the VM (e.g., '8G', '16G')";
+            };
+
+            cpus = lib.mkOption {
+              type = lib.types.int;
+              default = 4;
+              description = "Number of CPU cores to allocate to the VM";
+            };
+          };
+
           config = {
             environment.systemPackages = [ self.packages.${pkgs.system}.qvm ];
+
+            environment.etc."xdg/qvm/qvm.conf".text = ''
+              QVM_MEMORY="${cfg.memory}"
+              QVM_CPUS="${toString cfg.cpus}"
+            '';
           };
         };
     }
diff --git a/lib/common.sh b/lib/common.sh
index eb62440..61b5525 100644
--- a/lib/common.sh
+++ b/lib/common.sh
@@ -24,6 +24,7 @@ readonly QVM_SERIAL_LOG="$QVM_STATE_DIR/serial.log"
 readonly QVM_WORKSPACES_FILE="$QVM_STATE_DIR/workspaces.json"
 readonly QVM_USER_FLAKE="$QVM_CONFIG_DIR/flake"
 readonly QVM_VM_RUNNER="$QVM_DATA_DIR/run-vm"
+readonly QVM_CONFIG_FILE="$QVM_CONFIG_DIR/qvm.conf"
 
 # Cache directories for 9p mounts (shared between host and VM)
 readonly QVM_CARGO_HOME="$QVM_CACHE_DIR/cargo-home"