+    /*
+     * Sanitiy check for tdx:
+     * TDX uses generic loader to load bios instead of pflash.
+     */
+    for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
+        if (drive_get(IF_PFLASH, 0, i)) {
+            error_report("pflash not supported by VM type, "
+                         "use -device loader,file=<path>");
+            exit(1);
+        }

I suspect that catches only "-drive if=pflash,..."
but not "-machine pflash0=..."

Also: why does tdx not support flash?
Should be explained in the commit message.

thanks,
  Gerd