diff --git a/nixos/tests/installer.nix b/nixos/tests/installer.nix
index b6cb6a0c6d45..603448dfacc1 100644
--- a/nixos/tests/installer.nix
+++ b/nixos/tests/installer.nix
@@ -83,46 +83,34 @@ let
                   , postInstallCommands, preBootCommands, postBootCommands, extraConfig
                   , testSpecialisationConfig, testFlakeSwitch, clevisTest, clevisFallbackTest
                   }:
-    let iface = "virtio";
-        isEfi = bootLoader == "systemd-boot" || (bootLoader == "grub" && grubUseEfi);
-        bios  = if pkgs.stdenv.isAarch64 then "QEMU_EFI.fd" else "OVMF.fd";
+    let
+      qemu-common = import ../lib/qemu-common.nix { inherit (pkgs) lib pkgs; };
+      isEfi = bootLoader == "systemd-boot" || (bootLoader == "grub" && grubUseEfi);
+      qemu = qemu-common.qemuBinary pkgs.qemu_test;
     in if !isEfi && !pkgs.stdenv.hostPlatform.isx86 then ''
       machine.succeed("true")
     '' else ''
-      import subprocess
-      tpm_folder = os.environ['NIX_BUILD_TOP']
-      def assemble_qemu_flags():
-          flags = "-cpu max"
-          ${if (system == "x86_64-linux" || system == "i686-linux")
-            then ''flags += " -m 1024"''
-            else ''flags += " -m 768 -enable-kvm -machine virt,gic-version=host"''
-          }
-          ${optionalString clevisTest ''flags += f" -chardev socket,id=chrtpm,path={tpm_folder}/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0"''}
-          ${optionalString clevisTest ''flags += " -device virtio-net-pci,netdev=vlan1,mac=52:54:00:12:11:02 -netdev vde,id=vlan1,sock=\"$QEMU_VDE_SOCKET_1\""''}
-          return flags
-
-
-      qemu_flags = {"qemuFlags": assemble_qemu_flags()}
-
       import os
+      import subprocess
+
+      tpm_folder = os.environ['NIX_BUILD_TOP']
+
+      startcommand = "${qemu} -m 2048"
+
+      ${optionalString clevisTest ''
+        startcommand += f" -chardev socket,id=chrtpm,path={tpm_folder}/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0"
+        startcommand += " -device virtio-net-pci,netdev=vlan1,mac=52:54:00:12:11:02 -netdev vde,id=vlan1,sock=\"$QEMU_VDE_SOCKET_1\""
+      ''}
+      ${optionalString isEfi ''
+        startcommand +=" -drive if=pflash,format=raw,unit=0,readonly=on,file=${pkgs.OVMF.firmware} -drive if=pflash,format=raw,unit=1,readonly=on,file=${pkgs.OVMF.variables}"
+      ''}
 
       image_dir = machine.state_dir
       disk_image = os.path.join(image_dir, "machine.qcow2")
-
-      hd_flags = {
-          "hdaInterface": "${iface}",
-          "hda": disk_image,
-      }
-      ${optionalString isEfi ''
-        hd_flags.update(
-            bios="${pkgs.OVMF.fd}/FV/${bios}"
-        )''
-      }
-      default_flags = {**hd_flags, **qemu_flags}
-
+      startcommand += f" -drive file={disk_image},if=virtio,werror=report"
 
       def create_machine_named(name):
-          return create_machine({**default_flags, "name": name})
+          return create_machine({"startCommand": startcommand, "name": name})
 
       class Tpm:
             def __init__(self):
@@ -471,7 +459,7 @@ let
           # builds stuff in the VM, needs more juice
           virtualisation.diskSize = 8 * 1024;
           virtualisation.cores = 8;
-          virtualisation.memorySize = 1536;
+          virtualisation.memorySize = 2048;
 
           boot.initrd.systemd.enable = systemdStage1;