[Qemu-devel] [PATCH] qdev/core: Can not replug device on bus that allows one device

[Tony Krowiak <akrowiak@linux.ibm.com>]

If the maximum number of devices allowed on a bus is 1 and a device
which is plugged into the bus is subsequently unplugged, attempting to replug
the device fails with error "Bus 'xxx' does not support hotplugging".
The "error" is detected in the qbus_is_full(BusState *bus) function
(qdev_monitor.c) because bus->max_index >= bus_class->max_dev. The
root of the problem is that the bus->max_index is not decremented when a device
is unplugged from the bus. This patch fixes that problem.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
---
 hw/core/qdev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 6b3cc55b27c2..b35b0bf27925 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -59,6 +59,8 @@ static void bus_remove_child(BusState *bus, DeviceState *child)
             snprintf(name, sizeof(name), "child[%d]", kid->index);
             QTAILQ_REMOVE(&bus->children, kid, sibling);
 
+            bus->max_index--;
+
             /* This gives back ownership of kid->child back to us.  */
             object_property_del(OBJECT(bus), name, NULL);
             object_unref(OBJECT(kid->child));
-- 
2.7.4