From 7f026cc6d02746d553e5e3701d44fc89869bc7af Mon Sep 17 00:00:00 2001
From: Arthur Gautier <arthur.gautier@arista.com>
Date: Mon, 5 Sep 2022 17:10:59 -0700
Subject: [PATCH] qemu-vm: ensure we do not overwrite the partition table when
 EFI is in use

---
 nixos/modules/virtualisation/qemu-vm.nix | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/virtualisation/qemu-vm.nix b/nixos/modules/virtualisation/qemu-vm.nix
index 0207bfba82ad..b2e10da6891e 100644
--- a/nixos/modules/virtualisation/qemu-vm.nix
+++ b/nixos/modules/virtualisation/qemu-vm.nix
@@ -858,7 +858,8 @@ in
         # If the disk image appears to be empty, run mke2fs to
         # initialise.
         FSTYPE=$(blkid -o value -s TYPE ${cfg.bootDevice} || true)
-        if test -z "$FSTYPE"; then
+        PARTTYPE=$(blkid -o value -s PTTYPE ${cfg.bootDevice} || true)
+        if test -z "$FSTYPE" -a -z "$PARTTYPE"; then
             mke2fs -t ext4 ${cfg.bootDevice}
         fi
       '';