Allow choosing the bus that the device will be placed on, in case
the machine has more than one.  Otherwise, the bus may not match
the base address of the controller we attach it to.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 tests/qos-test.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/tests/qos-test.c b/tests/qos-test.c
index ae2fb5de1c..01b2a22c08 100644
--- a/tests/qos-test.c
+++ b/tests/qos-test.c
@@ -340,7 +340,8 @@ static void walk_path(QOSGraphNode *orig_path, int len)
     char **path_vec = g_new0(char *, (QOS_PATH_MAX_ELEMENT_SIZE * 2));
     int path_vec_size = 0;
 
-    char *after_cmd = NULL, *before_cmd = NULL, *after_device = NULL;
+    char *after_cmd, *before_cmd, *after_device;
+    GString *after_device_str = g_string_new("");
     char *node_name = orig_path->name, *path_str;
 
     GString *cmd_line = g_string_new("");
@@ -363,9 +364,8 @@ static void walk_path(QOSGraphNode *orig_path, int len)
         /* append node command line + previous edge command line */
         if (path->command_line && etype == QEDGE_CONSUMED_BY) {
             g_string_append(cmd_line, path->command_line);
-            if (after_device) {
-                g_string_append(cmd_line, after_device);
-            }
+            g_string_append(cmd_line, after_device_str->str);
+            g_string_truncate(after_device_str, 0);
         }
 
         path_vec[path_vec_size++] = qos_graph_edge_get_name(path->path_edge);
@@ -382,12 +382,15 @@ static void walk_path(QOSGraphNode *orig_path, int len)
         if (after_cmd) {
             g_string_append(cmd_line2, after_cmd);
         }
+        if (after_device) {
+            g_string_append(after_device_str, after_device);
+        }
     }
 
     path_vec[path_vec_size++] = NULL;
-    if (after_device) {
-        g_string_append(cmd_line, after_device);
-    }
+    g_string_append(cmd_line, after_device_str->str);
+    g_string_free(after_device_str, true);
+
     g_string_append(cmd_line, cmd_line2->str);
     g_string_free(cmd_line2, true);
 
-- 
2.21.0