conf: Don't overwrite KVM feature config struct if the feature is present twice

Don't allocate the struct if it exists already. This sidesteps the
discussion about whether forbidding multiple feature definitions makes
sense.

Fixes: a8e0f9c682143c63897de5c379d3ac3791c51970
Closes: https://gitlab.com/libvirt/libvirt/-/issues/670
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 5f0b35be5e68e538970dccf7da36b0e5458fe494..a263612ef7aed6735b7825d25f65a4ce44b1f67e 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -16657,10 +16657,12 @@ static int
 virDomainFeaturesKVMDefParse(virDomainDef *def,
                              xmlNodePtr node)
 {
-    g_autofree virDomainFeatureKVM *kvm = g_new0(virDomainFeatureKVM, 1);
     g_autoptr(GPtrArray) feats = virXMLNodeGetSubelementList(node, NULL);
     size_t i;
 
+    if (!def->kvm_features)
+        def->kvm_features = g_new0(virDomainFeatureKVM, 1);
+
     for (i = 0; i < feats->len; i++) {
         xmlNodePtr feat = g_ptr_array_index(feats, i);
         int feature;
@@ -16678,20 +16680,20 @@ virDomainFeaturesKVMDefParse(virDomainDef *def,
                                      &value) < 0)
             return -1;
 
-        kvm->features[feature] = value;
+        def->kvm_features->features[feature] = value;
 
         /* dirty ring feature should parse size property */
         if (feature == VIR_DOMAIN_KVM_DIRTY_RING &&
             value == VIR_TRISTATE_SWITCH_ON) {
 
             if (virXMLPropUInt(feat, "size", 0, VIR_XML_PROP_REQUIRED,
-                               &kvm->dirty_ring_size) < 0) {
+                               &def->kvm_features->dirty_ring_size) < 0) {
                 return -1;
             }
 
-            if (!VIR_IS_POW2(kvm->dirty_ring_size) ||
-                kvm->dirty_ring_size < 1024 ||
-                kvm->dirty_ring_size > 65536) {
+            if (!VIR_IS_POW2(def->kvm_features->dirty_ring_size) ||
+                def->kvm_features->dirty_ring_size < 1024 ||
+                def->kvm_features->dirty_ring_size > 65536) {
                 virReportError(VIR_ERR_XML_ERROR, "%s",
                                _("dirty ring must be power of 2 and ranges [1024, 65536]"));
 
@@ -16701,7 +16703,6 @@ virDomainFeaturesKVMDefParse(virDomainDef *def,
     }
 
     def->features[VIR_DOMAIN_FEATURE_KVM] = VIR_TRISTATE_SWITCH_ON;
-    def->kvm_features = g_steal_pointer(&kvm);
 
     return 0;
 }