diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
index 0acc9a3107..95cb0f935b 100644
--- a/hw/acpi/ich9.c
+++ b/hw/acpi/ich9.c
@@ -460,6 +460,18 @@ void ich9_pm_device_unplug_request_cb(HotplugHandler *hotplug_dev,
                                       errp);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU) &&
                !lpc->pm.cpu_hotplug_legacy) {
+        uint64_t negotiated = lpc->smi_negotiated_features;
+
+        if (negotiated & BIT_ULL(ICH9_LPC_SMI_F_BROADCAST_BIT) &&
+            !(negotiated & BIT_ULL(ICH9_LPC_SMI_F_CPU_HOT_UNPLUG_BIT))) {
+            error_setg(errp, "cpu hot-unplug with SMI wasn't enabled "
+                             "by firmware");
+            error_append_hint(errp, "update machine type to a version having "
+                                    "x-smi-cpu-hotunplug=on and firmware that "
+                                    "supports CPU hot-unplug with SMM");
+            return;
+        }
+
         acpi_cpu_unplug_request_cb(hotplug_dev, &lpc->pm.cpuhp_state,
                                    dev, errp);
     } else {