qemu: Add APIs for translating CPU features

So far we always used libvirt's name of each CPU feature relying on
backward compatible aliases in QEMU. The new translation table can be
used whenever QEMU mandates or prefers canonical feature names.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/qemu/qemu_capabilities.c

@@ -2848,6 +2848,70 @@ virQEMUCapsCPUFilterFeatures(const char *name,
 }
 
 
+typedef struct _virQEMUCapsCPUFeatureTranslationTable virQEMUCapsCPUFeatureTranslationTable;
+typedef virQEMUCapsCPUFeatureTranslationTable *virQEMUCapsCPUFeatureTranslationTablePtr;
+struct _virQEMUCapsCPUFeatureTranslationTable {
+    const char *libvirt;
+    const char *qemu;
+};
+
+virQEMUCapsCPUFeatureTranslationTable virQEMUCapsCPUFeaturesX86[] = {
+    {"cmp_legacy", "cmp-legacy"},
+    {"ds_cpl", "ds-cpl"},
+    {"fxsr_opt", "fxsr-opt"},
+    {"kvm_pv_eoi", "kvm-pv-eoi"},
+    {"kvm_pv_unhalt", "kvm-pv-unhalt"},
+    {"lahf_lm", "lahf-lm"},
+    {"nodeid_msr", "nodeid-msr"},
+    {"pclmuldq", "pclmulqdq"},
+    {"perfctr_core", "perfctr-core"},
+    {"perfctr_nb", "perfctr-nb"},
+    {"tsc_adjust", "tsc-adjust"},
+    {NULL, NULL}
+};
+
+
+static const char *
+virQEMUCapsCPUFeatureTranslate(virQEMUCapsPtr qemuCaps,
+                               const char *feature,
+                               bool reversed)
+{
+    virQEMUCapsCPUFeatureTranslationTablePtr table = NULL;
+    virQEMUCapsCPUFeatureTranslationTablePtr entry;
+
+    if (ARCH_IS_X86(qemuCaps->arch))
+        table = virQEMUCapsCPUFeaturesX86;
+
+    if (!table || !feature)
+        return feature;
+
+    for (entry = table; entry->libvirt; entry++) {
+        const char *key = reversed ? entry->qemu : entry->libvirt;
+
+        if (STREQ(feature, key))
+            return reversed ? entry->libvirt : entry->qemu;
+    }
+
+    return feature;
+}
+
+
+const char *
+virQEMUCapsCPUFeatureToQEMU(virQEMUCapsPtr qemuCaps,
+                            const char *feature)
+{
+    return virQEMUCapsCPUFeatureTranslate(qemuCaps, feature, false);
+}
+
+
+const char *
+virQEMUCapsCPUFeatureFromQEMU(virQEMUCapsPtr qemuCaps,
+                              const char *feature)
+{
+    return virQEMUCapsCPUFeatureTranslate(qemuCaps, feature, true);
+}
+
+
 /**
  * Returns  0 when host CPU model provided by QEMU was filled in qemuCaps,
  *          1 when the caller should fall back to using virCapsPtr->host.cpu,

src/qemu/qemu_capabilities.h

@@ -645,6 +645,14 @@ bool virQEMUCapsGuestIsNative(virArch host,
 bool virQEMUCapsCPUFilterFeatures(const char *name,
                                   void *opaque);
 
+const char *
+virQEMUCapsCPUFeatureToQEMU(virQEMUCapsPtr qemuCaps,
+                            const char *feature);
+
+const char *
+virQEMUCapsCPUFeatureFromQEMU(virQEMUCapsPtr qemuCaps,
+                              const char *feature);
+
 virSEVCapabilityPtr
 virQEMUCapsGetSEVCapabilities(virQEMUCapsPtr qemuCaps);