[libvirt] [PATCH v2 1/2] domain-conf: reorder usb controllers so the master is first

[Pavel Hrdina]

USB controllers can share the same 'index' which indicates, that there
is some sort of master-companion relationship.  Reorder the controllers
in XML in to place the master controller before its companions.  This is
required by QEMU to not fail with error message:

error: internal error: process exited while connecting to monitor:
2015-10-26T16:25:17.630265Z qemu-system-x86_64:
-device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x6:
USB bus 'usb.0' not found

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1166452

Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
---
 src/conf/domain_conf.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 0c559d2..3f22de2 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -13397,6 +13397,7 @@ void virDomainControllerInsertPreAlloced(virDomainDefPtr def,
     int idx;
     /* Tenatively plan to insert controller at the end. */
     int insertAt = -1;
+    virDomainControllerDefPtr current = NULL;
 
     /* Then work backwards looking for controllers of
      * the same type. If we find a controller with a
@@ -13404,19 +13405,29 @@ void virDomainControllerInsertPreAlloced(virDomainDefPtr def,
      * that position
      */
     for (idx = (def->ncontrollers - 1); idx >= 0; idx--) {
+        current = def->controllers[idx];
+        if (current->type == controller->type) {
+            if (current->idx > controller->idx) {
                 /* If bus matches and current controller is after
-         * new controller, then new controller should go here */
-        if (def->controllers[idx]->type == controller->type &&
-            def->controllers[idx]->idx > controller->idx) {
+                 * new controller, then new controller should go here
+                 * */
                 insertAt = idx;
-        } else if (def->controllers[idx]->type == controller->type &&
-                   insertAt == -1) {
+            } else if (controller->info.mastertype == VIR_DOMAIN_CONTROLLER_MASTER_NONE &&
+                       current->info.mastertype != VIR_DOMAIN_CONTROLLER_MASTER_NONE &&
+                       current->idx == controller->idx) {
+                /* If bus matches and index matches and new controller is
+                 * master and current isn't a master, then new controller
+                 * should go here to be placed before its companion
+                 */
+                insertAt = idx;
+            } else if (insertAt == -1) {
                 /* Last controller with match bus is before the
                  * new controller, then put new controller just after
                  */
                 insertAt = idx + 1;
             }
         }
+    }
 
     /* VIR_INSERT_ELEMENT_INPLACE will never return an error here. */
     ignore_value(VIR_INSERT_ELEMENT_INPLACE(def->controllers, insertAt,
-- 
2.6.2