From 4226f6fdfd886bc16fcc75129e91d29fd7ed23be Mon Sep 17 00:00:00 2001
From: Git Sagar <git@sagar.ch>
Date: Mon, 8 Jun 2026 13:53:00 +0530
Subject: [PATCH] add spice.vgamem option for QXL video memory

When spice.vgamem is set (e.g. 64), uses -device qxl-vga,vgamem_mb=N
instead of -vga qxl (which defaults to 16MB). When null (default),
uses -vga qxl for backwards compatibility.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 nixos/vms/config.nix           | 2 +-
 nixos/vms/submoduleOptions.nix | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/nixos/vms/config.nix b/nixos/vms/config.nix
index 6be8a44..d851fa2 100644
--- a/nixos/vms/config.nix
+++ b/nixos/vms/config.nix
@@ -178,7 +178,7 @@ let
           ${optionalString vmCfg.vnc.enable "-vnc ${vncArgs}"} \
           ${optionalString (vmCfg.spice.enable && vmCfg.spice.passwordFile != null) "-object secret,id=spice-pass-${vmCfg.name},file=${escapeShellArg vmCfg.spice.passwordFile}"} \
           ${optionalString vmCfg.spice.enable "-spice addr=${vmCfg.spice.addr},port=${toString vmCfg.spice.port}${optionalString (vmCfg.spice.passwordFile == null) ",disable-ticketing=on"}${optionalString (vmCfg.spice.passwordFile != null) ",password-secret=spice-pass-${vmCfg.name}"}"} \
-          ${optionalString vmCfg.spice.enable "-vga ${vmCfg.spice.displayDevice}"} \
+          ${optionalString vmCfg.spice.enable (if vmCfg.spice.displayDevice == "qxl" && vmCfg.spice.vgamem != null then "-vga none -device qxl-vga,vgamem_mb=${toString vmCfg.spice.vgamem}" else "-vga ${vmCfg.spice.displayDevice}")} \
           ${optionalString (vmCfg.spice.enable && vmCfg.spice.agent.enable) "-device virtio-serial-pci -chardev spicevmc,id=vdagent,debug=0,name=vdagent -device virtserialport,chardev=vdagent,name=com.redhat.spice.0"} \
           ${# Guest agent channel — prevents qemu-ga from spinning when virtio-win guest tools are installed
             optionalString isWindows "${optionalString (!vmCfg.spice.enable || !vmCfg.spice.agent.enable) "-device virtio-serial-pci"} -chardev socket,path=/tmp/qga-${vmCfg.name}.sock,server=on,wait=off,id=qga0 -device virtserialport,chardev=qga0,name=org.qemu.guest_agent.0"} \
diff --git a/nixos/vms/submoduleOptions.nix b/nixos/vms/submoduleOptions.nix
index 5dcca25..e871ca1 100644
--- a/nixos/vms/submoduleOptions.nix
+++ b/nixos/vms/submoduleOptions.nix
@@ -97,6 +97,11 @@ with lib;
         default = "qxl";
         description = "QEMU -vga type to use with SPICE (qxl, virtio, std, none).";
       };
+      vgamem = mkOption {
+        type = types.nullOr types.int;
+        default = null;
+        description = "Video memory in MB for QXL device. When set, uses -device qxl-vga instead of -vga qxl.";
+      };
     };
     nographic = mkOption {
       type = types.bool;