cpu: Introduce virCPUExpandFeatures

Having to use cpuBaseline with VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES
flag to expand CPU features is strange. Not to mention that cpuBaseline
can only expand host CPU definitions (i.e., it completely ignores
feature policies). The new virCPUExpandFeatures API is designed to work
with both host and guest CPU definitions.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

src/cpu/cpu.c

@@ -1076,3 +1076,53 @@ virCPUConvertLegacy(virArch arch,
     VIR_DEBUG("model=%s", NULLSTR(cpu->model));
     return 0;
 }
+
+
+static int
+virCPUFeatureCompare(const void *p1,
+                     const void *p2)
+{
+    const virCPUFeatureDef *f1 = p1;
+    const virCPUFeatureDef *f2 = p2;
+
+    return strcmp(f1->name, f2->name);
+}
+
+
+/**
+ * virCPUExpandFeatures:
+ *
+ * @arch: CPU architecture
+ * @cpu: CPU definition to be expanded
+ *
+ * Add all features implicitly enabled by the CPU model to the list of
+ * features. The @cpu is expected to be either a host or a guest representation
+ * of a host CPU, i.e., only VIR_CPU_FEATURE_REQUIRE and
+ * VIR_CPU_FEATURE_DISABLE policies are supported.
+ *
+ * The updated list of features in the CPU definition is sorted.
+ *
+ * Return -1 on error, 0 on success.
+ */
+int
+virCPUExpandFeatures(virArch arch,
+                     virCPUDefPtr cpu)
+{
+    struct cpuArchDriver *driver;
+
+    VIR_DEBUG("arch=%s, cpu=%p, model=%s, nfeatures=%zu",
+              virArchToString(arch), cpu, NULLSTR(cpu->model), cpu->nfeatures);
+
+    if (!(driver = cpuGetSubDriver(arch)))
+        return -1;
+
+    if (driver->expandFeatures &&
+        driver->expandFeatures(cpu) < 0)
+        return -1;
+
+    qsort(cpu->features, cpu->nfeatures, sizeof(*cpu->features),
+          virCPUFeatureCompare);
+
+    VIR_DEBUG("nfeatures=%zu", cpu->nfeatures);
+    return 0;
+}

src/cpu/cpu.h

@@ -116,6 +116,9 @@ typedef int
 typedef int
 (*virCPUArchConvertLegacy)(virCPUDefPtr cpu);
 
+typedef int
+(*virCPUArchExpandFeatures)(virCPUDefPtr cpu);
+
 struct cpuArchDriver {
     const char *name;
     const virArch *arch;
@@ -135,6 +138,7 @@ struct cpuArchDriver {
     virCPUArchGetModels getModels;
     virCPUArchTranslate translate;
     virCPUArchConvertLegacy convertLegacy;
+    virCPUArchExpandFeatures expandFeatures;
 };
 
 
@@ -247,6 +251,10 @@ virCPUConvertLegacy(virArch arch,
                     virCPUDefPtr cpu)
     ATTRIBUTE_NONNULL(2);
 
+int
+virCPUExpandFeatures(virArch arch,
+                     virCPUDefPtr cpu);
+
 /* virCPUDataFormat and virCPUDataParse are implemented for unit tests only and
  * have no real-life usage
  */

src/cpu/cpu_x86.c

@@ -2891,6 +2891,58 @@ virCPUx86Translate(virCPUDefPtr cpu,
 }
 
 
+static int
+virCPUx86ExpandFeatures(virCPUDefPtr cpu)
+{
+    virCPUx86MapPtr map;
+    virCPUDefPtr expanded = NULL;
+    virCPUx86ModelPtr model = NULL;
+    bool host = cpu->type == VIR_CPU_TYPE_HOST;
+    size_t i;
+    int ret = -1;
+
+    if (!(map = virCPUx86GetMap()))
+        goto cleanup;
+
+    if (!(expanded = virCPUDefCopy(cpu)))
+        goto cleanup;
+
+    virCPUDefFreeFeatures(expanded);
+
+    if (!(model = x86ModelFind(map, cpu->model))) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("unknown CPU model %s"), cpu->model);
+        goto cleanup;
+    }
+
+    if (!(model = x86ModelCopy(model)) ||
+        x86DataToCPUFeatures(expanded, host ? -1 : VIR_CPU_FEATURE_REQUIRE,
+                             &model->data, map) < 0)
+        goto cleanup;
+
+    for (i = 0; i < cpu->nfeatures; i++) {
+        virCPUFeatureDefPtr f = cpu->features + i;
+
+        if (!host &&
+            f->policy != VIR_CPU_FEATURE_REQUIRE &&
+            f->policy != VIR_CPU_FEATURE_DISABLE)
+            continue;
+
+        if (virCPUDefUpdateFeature(expanded, f->name, f->policy) < 0)
+            goto cleanup;
+    }
+
+    virCPUDefFreeModel(cpu);
+
+    ret = virCPUDefCopyModel(cpu, expanded, false);
+
+ cleanup:
+    virCPUDefFree(expanded);
+    x86ModelFree(model);
+    return ret;
+}
+
+
 int
 virCPUx86DataAddCPUID(virCPUDataPtr cpuData,
                       const virCPUx86CPUID *cpuid)
@@ -2965,4 +3017,5 @@ struct cpuArchDriver cpuDriverX86 = {
     .dataParse  = virCPUx86DataParse,
     .getModels  = virCPUx86GetModels,
     .translate  = virCPUx86Translate,
+    .expandFeatures = virCPUx86ExpandFeatures,
 };

src/libvirt_private.syms

@@ -1021,6 +1021,7 @@ virCPUDataFormat;
 virCPUDataFree;
 virCPUDataNew;
 virCPUDataParse;
+virCPUExpandFeatures;
 virCPUGetHost;
 virCPUGetModels;
 virCPUProbeHost;