diff --git a/gdbstub.c b/gdbstub.c
index de9b62b8f8..27e0923781 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -18,6 +18,7 @@
  */
 #include "qemu/osdep.h"
 #include "qapi/error.h"
+#include "qemu/error-report.h"
 #include "qemu/cutils.h"
 #include "cpu.h"
 #ifdef CONFIG_USER_ONLY
@@ -1732,6 +1733,12 @@ int gdbserver_start(const char *device)
     CharDriverState *mon_chr;
     ChardevCommon common = { 0 };
 
+    if (!first_cpu) {
+        error_report("gdbstub: meaningless to attach gdb to a "
+                     "machine without any CPU.");
+        return -1;
+    }
+
     if (!device)
         return -1;
     if (strcmp(device, "none") != 0) {