Author: Mathias Gibbens <gibmat@debian.org>
Description: Fix issues with old NVRAM  (ported from Incus)
From: https://github.com/lxc/incus/commit/7f63ae9a9fd3b083a8148a69094abdd1c07111e9
diff --git a/lxd/instance/drivers/driver_qemu.go b/lxd/instance/drivers/driver_qemu.go
index 8f19feb95..d73ba9594 100644
--- a/lxd/instance/drivers/driver_qemu.go
+++ b/lxd/instance/drivers/driver_qemu.go
@@ -1210,13 +1210,21 @@ func (d *qemu) start(stateful bool, op *operationlock.InstanceOperation) error {
 	}
 
 	// Copy OVMF settings firmware to nvram file if needed.
-	// This firmware file can be modified by the VM so it must be copied from the defaults.
-	if d.architectureSupportsUEFI(d.architecture) && (!shared.PathExists(d.nvramPath()) || shared.IsTrue(d.localConfig["volatile.apply_nvram"])) {
-		err = d.setupNvram()
-		if err != nil {
-			op.Done(err)
+	// Set up EDK2 NVRAM when on EFI.
+	if d.architectureSupportsUEFI(d.architecture) {
+		fi, err := os.Lstat(d.nvramPath())
+		if err != nil && !errors.Is(err, fs.ErrNotExist) {
 			return err
 		}
+
+		// Generate new NVRAM if missing, or if requested by the user or if the NVRAM file is of an invalid format (needs to be a valid symlink).
+		if shared.IsTrue(d.localConfig["volatile.apply_nvram"]) || fi == nil || fi.Mode()&os.ModeSymlink != os.ModeSymlink {
+			err = d.setupNvram()
+			if err != nil {
+				op.Done(err)
+				return err
+			}
+		}
 	}
 
 	// Clear volatile.apply_nvram if set.