s390x: change the QEMU cpu model to a stripped down z12

We are good enough to boot upstream Linux kernels / Fedora 26/27. That
should be sufficient for now.

As the QEMU CPU model is migration safe, let's add compatibility code.
Generate the feature list to reduce the chance of messing things up in the
future.

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20171208165529.14124-1-david@redhat.com>
[CH: squashed 's390x/cpumodel: make qemu cpu model play with "none" machine'
(20171213132407.5227-1-david@redhat.com) and 's390x/tcg: don't include z13
features in the qemu model' (20171213171512.17601-1-david@redhat.com) into
patch]
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

1 files changed, 47 insertions, 59 deletions

diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
index edac7fdecf..212a5f0697 100644
--- a/target/s390x/cpu_models.c
+++ b/target/s390x/cpu_models.c
@@ -15,7 +15,6 @@
 #include "internal.h"
 #include "kvm_s390x.h"
 #include "sysemu/kvm.h"
-#include "gen-features.h"
 #include "qapi/error.h"
 #include "qapi/visitor.h"
 #include "qemu/error-report.h"
@@ -81,6 +80,12 @@ static S390CPUDef s390_cpu_defs[] = {
     CPUDEF_INIT(0x3906, 14, 1, 47, 0x08000000U, "z14", "IBM z14 GA1"),
 };
 
+#define QEMU_MAX_CPU_TYPE 0x2827
+#define QEMU_MAX_CPU_GEN 12
+#define QEMU_MAX_CPU_EC_GA 2
+static const S390FeatInit qemu_max_cpu_feat_init = { S390_FEAT_LIST_QEMU_MAX };
+static S390FeatBitmap qemu_max_cpu_feat;
+
 /* features part of a base model but not relevant for finding a base model */
 S390FeatBitmap ignored_base_feat;
 
@@ -812,51 +817,6 @@ static void check_compatibility(const S390CPUModel *max_model,
                   "available in the configuration: ");
 }
 
-/**
- * The base TCG CPU model "qemu" is based on the z900. However, we already
- * can also emulate some additional features of later CPU generations, so
- * we add these additional feature bits here.
- */
-static void add_qemu_cpu_model_features(S390FeatBitmap fbm)
-{
-    static const int feats[] = {
-        S390_FEAT_DAT_ENH,
-        S390_FEAT_IDTE_SEGMENT,
-        S390_FEAT_STFLE,
-        S390_FEAT_SENSE_RUNNING_STATUS,
-        S390_FEAT_EXTENDED_TRANSLATION_2,
-        S390_FEAT_MSA,
-        S390_FEAT_LONG_DISPLACEMENT,
-        S390_FEAT_LONG_DISPLACEMENT_FAST,
-        S390_FEAT_EXTENDED_IMMEDIATE,
-        S390_FEAT_EXTENDED_TRANSLATION_3,
-        S390_FEAT_ETF2_ENH,
-        S390_FEAT_STORE_CLOCK_FAST,
-        S390_FEAT_MOVE_WITH_OPTIONAL_SPEC,
-        S390_FEAT_ETF3_ENH,
-        S390_FEAT_EXTRACT_CPU_TIME,
-        S390_FEAT_COMPARE_AND_SWAP_AND_STORE,
-        S390_FEAT_COMPARE_AND_SWAP_AND_STORE_2,
-        S390_FEAT_GENERAL_INSTRUCTIONS_EXT,
-        S390_FEAT_EXECUTE_EXT,
-        S390_FEAT_SET_PROGRAM_PARAMETERS,
-        S390_FEAT_FLOATING_POINT_SUPPPORT_ENH,
-        S390_FEAT_STFLE_45,
-        S390_FEAT_STFLE_49,
-        S390_FEAT_LOCAL_TLB_CLEARING,
-        S390_FEAT_INTERLOCKED_ACCESS_2,
-        S390_FEAT_STFLE_53,
-        S390_FEAT_MSA_EXT_5,
-        S390_FEAT_MSA_EXT_3,
-        S390_FEAT_MSA_EXT_4,
-    };
-    int i;
-
-    for (i = 0; i < ARRAY_SIZE(feats); i++) {
-        set_bit(feats[i], fbm);
-    }
-}
-
 static S390CPUModel *get_max_cpu_model(Error **errp)
 {
     static S390CPUModel max_model;
@@ -869,12 +829,10 @@ static S390CPUModel *get_max_cpu_model(Error **errp)
     if (kvm_enabled()) {
         kvm_s390_get_host_cpu_model(&max_model, errp);
     } else {
-        /* TCG emulates a z900 (with some optional additional features) */
-        max_model.def = &s390_cpu_defs[0];
-        bitmap_copy(max_model.features, max_model.def->default_feat,
-                    S390_FEAT_MAX);
-        add_qemu_cpu_model_features(max_model.features);
-    }
+        max_model.def = s390_find_cpu_def(QEMU_MAX_CPU_TYPE, QEMU_MAX_CPU_GEN,
+                                          QEMU_MAX_CPU_EC_GA, NULL);
+        bitmap_copy(max_model.features, qemu_max_cpu_feat, S390_FEAT_MAX);
+   }
     if (!*errp) {
         cached = true;
         return &max_model;
@@ -1130,18 +1088,42 @@ static void s390_host_cpu_model_initfn(Object *obj)
 }
 #endif
 
+static S390CPUDef s390_qemu_cpu_def;
+static S390CPUModel s390_qemu_cpu_model;
+
+/* Set the qemu CPU model (on machine initialization). Must not be called
+ * once CPUs have been created.
+ */
+void s390_set_qemu_cpu_model(uint16_t type, uint8_t gen, uint8_t ec_ga,
+                             const S390FeatInit feat_init)
+{
+    const S390CPUDef *def = s390_find_cpu_def(type, gen, ec_ga, NULL);
+
+    g_assert(def);
+    g_assert(QTAILQ_EMPTY(&cpus));
+
+    /* TCG emulates some features that can usually not be enabled with
+     * the emulated machine generation. Make sure they can be enabled
+     * when using the QEMU model by adding them to full_feat. We have
+     * to copy the definition to do that.
+     */
+    memcpy(&s390_qemu_cpu_def, def, sizeof(s390_qemu_cpu_def));
+    bitmap_or(s390_qemu_cpu_def.full_feat, s390_qemu_cpu_def.full_feat,
+              qemu_max_cpu_feat, S390_FEAT_MAX);
+
+    /* build the CPU model */
+    s390_qemu_cpu_model.def = &s390_qemu_cpu_def;
+    bitmap_zero(s390_qemu_cpu_model.features, S390_FEAT_MAX);
+    s390_init_feat_bitmap(feat_init, s390_qemu_cpu_model.features);
+}
+
 static void s390_qemu_cpu_model_initfn(Object *obj)
 {
-    static S390CPUDef s390_qemu_cpu_defs;
     S390CPU *cpu = S390_CPU(obj);
 
     cpu->model = g_malloc0(sizeof(*cpu->model));
-    /* TCG emulates a z900 (with some optional additional features) */
-    memcpy(&s390_qemu_cpu_defs, &s390_cpu_defs[0], sizeof(s390_qemu_cpu_defs));
-    add_qemu_cpu_model_features(s390_qemu_cpu_defs.full_feat);
-    cpu->model->def = &s390_qemu_cpu_defs;
-    bitmap_copy(cpu->model->features, cpu->model->def->default_feat,
-                S390_FEAT_MAX);
+    /* copy the CPU model so we can modify it */
+    memcpy(cpu->model, &s390_qemu_cpu_model, sizeof(*cpu->model));
 }
 
 static void s390_cpu_model_finalize(Object *obj)
@@ -1282,11 +1264,13 @@ static void init_ignored_base_feat(void)
 
 static void register_types(void)
 {
+    static const S390FeatInit qemu_latest_init = { S390_FEAT_LIST_QEMU_LATEST };
     int i;
 
     init_ignored_base_feat();
 
     /* init all bitmaps from gnerated data initially */
+    s390_init_feat_bitmap(qemu_max_cpu_feat_init, qemu_max_cpu_feat);
     for (i = 0; i < ARRAY_SIZE(s390_cpu_defs); i++) {
         s390_init_feat_bitmap(s390_cpu_defs[i].base_init,
                               s390_cpu_defs[i].base_feat);
@@ -1296,6 +1280,10 @@ static void register_types(void)
                               s390_cpu_defs[i].full_feat);
     }
 
+    /* initialize the qemu model with latest definition */
+    s390_set_qemu_cpu_model(QEMU_MAX_CPU_TYPE, QEMU_MAX_CPU_GEN,
+                            QEMU_MAX_CPU_EC_GA, qemu_latest_init);
+
     for (i = 0; i < ARRAY_SIZE(s390_cpu_defs); i++) {
         char *base_name = s390_base_cpu_type_name(s390_cpu_defs[i].name);
         TypeInfo ti_base = {