libqos/qgraph: add qos_node_create_driver_named()

So far the qos subsystem of the qtest framework had the limitation
that only one instance of the same official QEMU (QMP) driver name
could be created for qtests. That's because a) the created qos
node names must always be unique, b) the node name must match the
official QEMU driver name being instantiated and c) all nodes are
in a global space shared by all tests.

This patch removes this limitation by introducing a new function
qos_node_create_driver_named() which allows test case authors to
specify a node name being different from the actual associated
QEMU driver name. It fills the new 'qemu_name' field of
QOSGraphNode for that purpose.

Adjust build_driver_cmd_line() and qos_graph_node_set_availability()
to correctly deal with either accessing node name vs. node's
qemu_name correctly.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <3be962ff38f3396f8040deaa5ffdab525c4e0b16.1611704181.git.qemu_oss@crudebyte.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 51 insertions, 3 deletions

diff --git a/tests/qtest/libqos/qgraph.c b/tests/qtest/libqos/qgraph.c
index fc49cfa879..61faf6b27d 100644
--- a/tests/qtest/libqos/qgraph.c
+++ b/tests/qtest/libqos/qgraph.c
@@ -153,6 +153,7 @@ static QOSGraphNode *create_node(const char *name, QOSNodeType type)
 static void destroy_node(void *val)
 {
     QOSGraphNode *node = val;
+    g_free(node->qemu_name);
     g_free(node->command_line);
     g_free(node);
 }
@@ -286,7 +287,8 @@ static void build_machine_cmd_line(QOSGraphNode *node, const char *args)
  */
 static void build_driver_cmd_line(QOSGraphNode *node)
 {
-    node->command_line = g_strconcat(" -device ", node->name, NULL);
+    const char *name = node->qemu_name ?: node->name;
+    node->command_line = g_strconcat(" -device ", name, NULL);
 }
 
 /* qos_print_cb(): callback prints all path found by the DFS algorithm. */
@@ -631,6 +633,15 @@ void qos_node_create_driver(const char *name, QOSCreateDriverFunc function)
     node->u.driver.constructor = function;
 }
 
+void qos_node_create_driver_named(const char *name, const char *qemu_name,
+                                  QOSCreateDriverFunc function)
+{
+    QOSGraphNode *node = create_node(name, QNODE_DRIVER);
+    node->qemu_name = g_strdup(qemu_name);
+    build_driver_cmd_line(node);
+    node->u.driver.constructor = function;
+}
+
 void qos_node_contains(const char *container, const char *contained,
                        QOSGraphEdgeOptions *opts, ...)
 {
@@ -663,7 +674,7 @@ void qos_node_consumes(const char *consumer, const char *interface,
     add_edge(interface, consumer, QEDGE_CONSUMED_BY, opts);
 }
 
-void qos_graph_node_set_availability(const char *node, bool av)
+static void qos_graph_node_set_availability_explicit(const char *node, bool av)
 {
     QOSGraphEdgeList *elist;
     QOSGraphNode *n = search_node(node);
@@ -678,9 +689,46 @@ void qos_graph_node_set_availability(const char *node, bool av)
     }
     QSLIST_FOREACH_SAFE(e, elist, edge_list, next) {
         if (e->type == QEDGE_CONTAINS || e->type == QEDGE_PRODUCES) {
-            qos_graph_node_set_availability(e->dest, av);
+            qos_graph_node_set_availability_explicit(e->dest, av);
+        }
+    }
+}
+
+/*
+ * Behaves as qos_graph_node_set_availability_explicit(), except that the
+ * former always matches by node name only, whereas this function matches both
+ * by node name and node's optional 'qemu_name' field.
+ */
+void qos_graph_node_set_availability(const char *node, bool av)
+{
+    GList *l;
+    QOSGraphEdgeList *elist;
+    QOSGraphEdge *e, *next;
+    QOSGraphNode *n;
+    GList *keys = g_hash_table_get_keys(node_table);
+
+    for (l = keys; l != NULL; l = l->next) {
+        const gchar *key = l->data;
+        n = g_hash_table_lookup(node_table, key);
+        /*
+         * node's 'qemu_name' is set if there is more than one device with
+         * the same QEMU (QMP) device name
+         */
+        const char *node_name = n->qemu_name ?: n->name;
+        if (g_strcmp0(node_name, node) == 0) {
+            n->available = av;
+            elist = get_edgelist(n->name);
+            if (elist) {
+                QSLIST_FOREACH_SAFE(e, elist, edge_list, next) {
+                    if (e->type == QEDGE_CONTAINS || e->type == QEDGE_PRODUCES)
+                    {
+                        qos_graph_node_set_availability_explicit(e->dest, av);
+                    }
+                }
+            }
         }
     }
+    g_list_free(keys);
 }
 
 void qos_graph_foreach_test_path(QOSTestCallback fn)