diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi
index 11b870c5c1..5d2d7a3588 100644
--- a/qemu-deprecated.texi
+++ b/qemu-deprecated.texi
@@ -86,6 +86,18 @@ for these file types is 'host_cdrom' or 'host_device' as appropriate.
 The @option{name} parameter of the @option{-net} option is a synonym
 for the @option{id} parameter, which should now be used instead.
 
+@subsection -smp (invalid topologies) (since 3.1)
+
+CPU topology properties should describe whole machine topology including
+possible CPUs.
+
+However, historically it was possible to start QEMU with an incorrect topology
+where @math{@var{n} <= @var{sockets} * @var{cores} * @var{threads} < @var{maxcpus}},
+which could lead to an incorrect topology enumeration by the guest.
+Support for invalid topologies will be removed, the user must ensure
+topologies described with -smp include all possible cpus, i.e.
+  @math{@var{sockets} * @var{cores} * @var{threads} = @var{maxcpus}}.
+
 @section QEMU Machine Protocol (QMP) commands
 
 @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0)
diff --git a/tests/cpu-plug-test.c b/tests/cpu-plug-test.c
index 3e93c8e096..f4a677d238 100644
--- a/tests/cpu-plug-test.c
+++ b/tests/cpu-plug-test.c
@@ -32,12 +32,12 @@ static void test_plug_with_cpu_add(gconstpointer data)
     unsigned int i;
 
     args = g_strdup_printf("-machine %s -cpu %s "
-                           "-smp sockets=%u,cores=%u,threads=%u,maxcpus=%u",
+                           "-smp 1,sockets=%u,cores=%u,threads=%u,maxcpus=%u",
                            s->machine, s->cpu_model,
                            s->sockets, s->cores, s->threads, s->maxcpus);
     qtest_start(args);
 
-    for (i = s->sockets * s->cores * s->threads; i < s->maxcpus; i++) {
+    for (i = 1; i < s->maxcpus; i++) {
         response = qmp("{ 'execute': 'cpu-add',"
                        "  'arguments': { 'id': %d } }", i);
         g_assert(response);
@@ -56,7 +56,7 @@ static void test_plug_without_cpu_add(gconstpointer data)
     QDict *response;
 
     args = g_strdup_printf("-machine %s -cpu %s "
-                           "-smp sockets=%u,cores=%u,threads=%u,maxcpus=%u",
+                           "-smp 1,sockets=%u,cores=%u,threads=%u,maxcpus=%u",
                            s->machine, s->cpu_model,
                            s->sockets, s->cores, s->threads, s->maxcpus);
     qtest_start(args);
@@ -79,12 +79,12 @@ static void test_plug_with_device_add_x86(gconstpointer data)
     unsigned int s, c, t;
 
     args = g_strdup_printf("-machine %s -cpu %s "
-                           "-smp sockets=%u,cores=%u,threads=%u,maxcpus=%u",
+                           "-smp 1,sockets=%u,cores=%u,threads=%u,maxcpus=%u",
                            td->machine, td->cpu_model,
                            td->sockets, td->cores, td->threads, td->maxcpus);
     qtest_start(args);
 
-    for (s = td->sockets; s < td->maxcpus / td->cores / td->threads; s++) {
+    for (s = 1; s < td->sockets; s++) {
         for (c = 0; c < td->cores; c++) {
             for (t = 0; t < td->threads; t++) {
                 char *id = g_strdup_printf("id-%i-%i-%i", s, c, t);
@@ -113,7 +113,7 @@ static void test_plug_with_device_add_coreid(gconstpointer data)
                            td->sockets, td->cores, td->threads, td->maxcpus);
     qtest_start(args);
 
-    for (c = td->cores; c < td->maxcpus / td->sockets / td->threads; c++) {
+    for (c = 1; c < td->cores; c++) {
         char *id = g_strdup_printf("id-%i", c);
         qtest_qmp_device_add(td->device_model, id, "{'core-id':%u}", c);
         g_free(id);
@@ -148,7 +148,7 @@ static void add_pc_test_case(const char *mname)
     data->sockets = 1;
     data->cores = 3;
     data->threads = 2;
-    data->maxcpus = data->sockets * data->cores * data->threads * 2;
+    data->maxcpus = data->sockets * data->cores * data->threads;
     if (g_str_has_suffix(mname, "-1.4") ||
         (strcmp(mname, "pc-1.3") == 0) ||
         (strcmp(mname, "pc-1.2") == 0) ||
@@ -203,7 +203,7 @@ static void add_pseries_test_case(const char *mname)
     data->sockets = 2;
     data->cores = 3;
     data->threads = 1;
-    data->maxcpus = data->sockets * data->cores * data->threads * 2;
+    data->maxcpus = data->sockets * data->cores * data->threads;
 
     path = g_strdup_printf("cpu-plug/%s/device-add/%ux%ux%u&maxcpus=%u",
                            mname, data->sockets, data->cores,
@@ -229,7 +229,7 @@ static void add_s390x_test_case(const char *mname)
     data->sockets = 1;
     data->cores = 3;
     data->threads = 1;
-    data->maxcpus = data->sockets * data->cores * data->threads * 2;
+    data->maxcpus = data->sockets * data->cores * data->threads;
 
     data2 = g_memdup(data, sizeof(PlugTestData));
     data2->machine = g_strdup(data->machine);
diff --git a/vl.c b/vl.c
index b2a405f80f..31febe965c 100644
--- a/vl.c
+++ b/vl.c
@@ -1266,6 +1266,13 @@ static void smp_parse(QemuOpts *opts)
             exit(1);
         }
 
+        if (sockets * cores * threads != max_cpus) {
+            warn_report("Invalid CPU topology deprecated: "
+                        "sockets (%u) * cores (%u) * threads (%u) "
+                        "!= maxcpus (%u)",
+                        sockets, cores, threads, max_cpus);
+        }
+
         smp_cpus = cpus;
         smp_cores = cores;
         smp_threads = threads;