[libvirt] [PATCH v5 12/12] target-i386: Return runnability information on query-cpu-definitions
Fill the "unavailable-features" field on the x86 implementation
of query-cpu-definitions.
Cc: Jiri Denemark <jdenemar(a)redhat.com>
Cc: libvir-list(a)redhat.com
Signed-off-by: Eduardo Habkost <ehabkost(a)redhat.com>
---
Changes v3 -> v4:
* Handle missing XSAVE components cleanly, but looking up
the original feature that required it
* Use x86_cpu_load_features() function
Changes v2 -> v3:
* Create a x86_cpu_feature_name() function, to
isolate the code that returns the property name
Changes v1 -> v2:
* Updated to the new schema: no @runnable field, and
always report @unavailable-features as present
---
target-i386/cpu.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 73 insertions(+)
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index e4b45e3..620889f 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -1945,6 +1945,27 @@ static inline void feat2prop(char *s)
}
}
+/* Return the feature property name for a feature flag bit */
+static const char *x86_cpu_feature_name(FeatureWord w, int bitnr)
+{
+ /* XSAVE components are automatically enabled by other features,
+ * so return the original feature name instead
+ */
+ if (w == FEAT_XSAVE_COMP_LO || w == FEAT_XSAVE_COMP_HI) {
+ int comp = (w == FEAT_XSAVE_COMP_HI) ? bitnr + 32 : bitnr;
+
+ if (comp < ARRAY_SIZE(x86_ext_save_areas) &&
+ x86_ext_save_areas[comp].bits) {
+ w = x86_ext_save_areas[comp].feature;
+ bitnr = ctz32(x86_ext_save_areas[comp].bits);
+ }
+ }
+
+ assert(bitnr < 32);
+ assert(w < FEATURE_WORDS);
+ return feature_word_info[w].feat_names[bitnr];
+}
+
/* Compatibily hack to maintain legacy +-feat semantic,
* where +-feat overwrites any feature set by
* feat=on|feat even if the later is parsed after +-feat
@@ -2030,6 +2051,56 @@ static void x86_cpu_parse_featurestr(const char *typename, char
*features,
}
}
+static void x86_cpu_load_features(X86CPU *cpu, Error **errp);
+
+/* Check for missing features that may prevent the CPU class from
+ * running using the current machine and accelerator.
+ */
+static void x86_cpu_class_check_missing_features(X86CPUClass *xcc,
+ strList **missing_feats)
+{
+ X86CPU *xc;
+ FeatureWord w;
+ Error *err = NULL;
+ strList **next = missing_feats;
+
+ if (xcc->kvm_required && !kvm_enabled()) {
+ strList *new = g_new0(strList, 1);
+ new->value = g_strdup("kvm");;
+ *missing_feats = new;
+ return;
+ }
+
+ xc = X86_CPU(object_new(object_class_get_name(OBJECT_CLASS(xcc))));
+
+ x86_cpu_load_features(xc, &err);
+ if (err) {
+ /* Errors at x86_cpu_load_features should never happen,
+ * but in case it does, just report the model as not
+ * runnable at all using the "type" property.
+ */
+ strList *new = g_new0(strList, 1);
+ new->value = g_strdup("type");
+ *next = new;
+ next = &new->next;
+ }
+
+ for (w = 0; w < FEATURE_WORDS; w++) {
+ uint32_t filtered = xc->filtered_features[w];
+ int i;
+ for (i = 0; i < 32; i++) {
+ if (filtered & (1UL << i)) {
+ strList *new = g_new0(strList, 1);
+ new->value = g_strdup(x86_cpu_feature_name(w, i));
+ *next = new;
+ next = &new->next;
+ }
+ }
+ }
+
+ object_unref(OBJECT(xc));
+}
+
/* Print all cpuid feature names in featureset
*/
static void listflags(FILE *f, fprintf_function print, const char **featureset)
@@ -2122,6 +2193,8 @@ static void x86_cpu_definition_entry(gpointer data, gpointer
user_data)
info = g_malloc0(sizeof(*info));
info->name = x86_cpu_class_get_model_name(cc);
+ x86_cpu_class_check_missing_features(cc, &info->unavailable_features);
+ info->has_unavailable_features = true;
entry = g_malloc0(sizeof(*entry));
entry->value = info;
--
2.7.4