[Qemu-devel] [RFC PATCH v3 2/2] qbus : add a maximum device.

[fred . konrad]

From: KONRAD Frederic <address@hidden>

Only one device can be connected to virtio-bus.
This patch add a field max_dev which is :
    * the maximum amount of devices connected on the bus ( when
    * max_dev!=0 ).
    * have no effect ( when max_dev=0 ).

The function qbus_find_recursive is modified :
    * to return a non full bus when the "bus=" option is not present.
    * to give an error when the "bus=" option is pointing a full bus.

Signed-off-by: KONRAD Frederic <address@hidden>
---
 hw/qdev-core.h    |    1 +
 hw/qdev-monitor.c |   12 ++++++++++++
 2 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/hw/qdev-core.h b/hw/qdev-core.h
index fce9e22..15161f7 100644
--- a/hw/qdev-core.h
+++ b/hw/qdev-core.h
@@ -118,6 +118,7 @@ struct BusState {
     bool qom_allocated;
     bool glib_allocated;
     int max_index;
+    int max_dev;
     QTAILQ_HEAD(ChildrenHead, BusChild) children;
     QLIST_ENTRY(BusState) sibling;
 };
diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 479eecd..66d8e59 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -293,6 +293,18 @@ static BusState *qbus_find_recursive(BusState *bus, const 
char *name,
         (strcmp(object_get_typename(OBJECT(bus)), bus_typename) != 0)) {
         match = 0;
     }
+
+    /* Check if max_dev is reached */
+    if ((bus->max_dev != 0) && (bus->max_dev <= bus->max_index)) {
+        if (name != NULL) {
+            error_report("maximum amount of devices reached for %s\n", 
+                         bus->name);
+            return NULL;
+        } else {
+            match = 0;
+        }
+    }
+
     if (match) {
         return bus;
     }
-- 
1.7.1