[PATCH v4] target/s390x: filter deprecated properties based on model expansion type

[Collin Walling <walling@linux.ibm.com>]

Currently, there is no way to execute the query-cpu-model-expansion
command to retrieve a comprehenisve list of deprecated properties, as
the result is dependent per-model. To enable this, the expansion output
is modified as such:

When reporting a "static" CPU model, the command will only show
deprecated properties that are a subset of the model's *enabled*
properties. This is more accurate than how the query was handled
before, which blindly reported properties that were never introduced
for certain models.

When reporting a "full" CPU model, show the *entire* list of deprecated
properties regardless if they are supported on the model. A full
expansion outputs all known CPU model properties anyway, so it makes
sense to report all deprecated properties here too. This allows
management apps to query a single model (e.g. host) to acquire the
full list of deprecated properties.

Additionally, the @deprecated-props array has been moved from the
CpuModelInfo struct to the CpuModelExpansionInfo struct, since the data
did not belong in the former.

Acked-by: David Hildenbrand <david@redhat.com>
Suggested-by: Jiri Denemark <jdenemar@redhat.com>
Signed-off-by: Collin Walling <walling@linux.ibm.com>
---

Changelog:

    v4
    - @deprecated-props moved to CpuModelExpansionInfo
    - deprecated features code moved from cpu_info_from_model to 
        qmp_query_cpu_model_expansion function
    - reorganized commit message to mention "static" first and "full"
        second, akin to how it's documented in the QAPI doc

    v3
    - Removed the 'note' and cleaned up documentation
    - Revised commit message

    v2
    - Changed commit message
    - Added documentation reflecting this change
    - Made code changes that more accurately filter the deprecated
        properties based on expansion type.  This change makes it
        so that the deprecated-properties reported for a static model
        expansion are a subset of the model's properties instead of
        the model's full-definition properties.

---
 qapi/machine-target.json         | 17 ++++++++++-------
 target/s390x/cpu_models_sysemu.c | 27 +++++++++++++++++++--------
 2 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index a8d9ec87f5..3e711d4178 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -20,16 +20,11 @@
 #
 # @props: a dictionary of QOM properties to be applied
 #
-# @deprecated-props: a list of properties that are flagged as deprecated
-#     by the CPU vendor.  These props are a subset of the full model's
-#     definition list of properties. (since 9.1)
-#
 # Since: 2.8
 ##
 { 'struct': 'CpuModelInfo',
   'data': { 'name': 'str',
-            '*props': 'any',
-            '*deprecated-props': ['str'] } }
+            '*props': 'any' } }
 
 ##
 # @CpuModelExpansionType:
@@ -247,10 +242,18 @@
 #
 # @model: the expanded CpuModelInfo.
 #
+# @deprecated-props: a list of properties that are flagged as deprecated
+#     by the CPU vendor.  The list depends on the CpuModelExpansionType:
+#     "static" properties are a subset of the enabled-properties for
+#     the expanded model; "full" properties are a set of properties
+#     that are deprecated across all models for the architecture.
+#     (since: 9.1).
+#
 # Since: 2.8
 ##
 { 'struct': 'CpuModelExpansionInfo',
-  'data': { 'model': 'CpuModelInfo' },
+  'data': { 'model': 'CpuModelInfo',
+            '*deprecated-props': ['str'] },
   'if': { 'any': [ 'TARGET_S390X',
                    'TARGET_I386',
                    'TARGET_ARM',
diff --git a/target/s390x/cpu_models_sysemu.c b/target/s390x/cpu_models_sysemu.c
index 977fbc6522..44e7587acb 100644
--- a/target/s390x/cpu_models_sysemu.c
+++ b/target/s390x/cpu_models_sysemu.c
@@ -206,14 +206,6 @@ static void cpu_info_from_model(CpuModelInfo *info, const S390CPUModel *model,
     } else {
         info->props = QOBJECT(qdict);
     }
-
-    /* features flagged as deprecated */
-    bitmap_zero(bitmap, S390_FEAT_MAX);
-    s390_get_deprecated_features(bitmap);
-
-    bitmap_and(bitmap, bitmap, model->def->full_feat, S390_FEAT_MAX);
-    s390_feat_bitmap_to_ascii(bitmap, &info->deprecated_props, list_add_feat);
-    info->has_deprecated_props = !!info->deprecated_props;
 }
 
 CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
@@ -224,6 +216,7 @@ CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
     CpuModelExpansionInfo *expansion_info = NULL;
     S390CPUModel s390_model;
     bool delta_changes = false;
+    S390FeatBitmap deprecated_feats;
 
     /* convert it to our internal representation */
     cpu_model_from_info(&s390_model, model, "model", &err);
@@ -243,6 +236,24 @@ CpuModelExpansionInfo *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
     expansion_info = g_new0(CpuModelExpansionInfo, 1);
     expansion_info->model = g_malloc0(sizeof(*expansion_info->model));
     cpu_info_from_model(expansion_info->model, &s390_model, delta_changes);
+
+    /* populate list of deprecated features */
+    bitmap_zero(deprecated_feats, S390_FEAT_MAX);
+    s390_get_deprecated_features(deprecated_feats);
+
+    if (delta_changes) {
+        /*
+         * Only populate deprecated features that are a
+         * subset of the features enabled on the CPU model.
+         */
+        bitmap_and(deprecated_feats, deprecated_feats,
+                   s390_model.features, S390_FEAT_MAX);
+    }
+
+    s390_feat_bitmap_to_ascii(deprecated_feats,
+                              &expansion_info->deprecated_props, list_add_feat);
+    expansion_info->has_deprecated_props = !!expansion_info->deprecated_props;
+
     return expansion_info;
 }
 
-- 
2.45.1