qdev/core: fix qbus_is_full()
The qbus_is_full(BusState *bus) function (qdev_monitor.c) compares the max_index value of the BusState structure with the max_dev value of the BusClass structure to determine whether the maximum number of children has been reached for the bus. The problem is, the max_index field of the BusState structure does not necessarily reflect the number of devices that have been plugged into the bus. Whenever a child device is plugged into the bus, the bus's max_index value is assigned to the child device and then incremented. If the child is subsequently unplugged, the value of the max_index does not change and no longer reflects the number of children. When the bus's max_index value reaches the maximum number of devices allowed for the bus (i.e., the max_dev field in the BusClass structure), attempts to plug another device will be rejected claiming that the bus is full -- even if the bus is actually empty. To resolve the problem, a new 'num_children' field is being added to the BusState structure to keep track of the number of children plugged into the bus. It will be incremented when a child is plugged, and decremented when a child is unplugged. Signed-off-by: NTony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Pierre Morel<pmorel@linux.ibm.com> Reviewed-by: NHalil Pasic <pasic@linux.ibm.com> Message-Id: <1545062250-7573-1-git-send-email-akrowiak@linux.ibm.com> Reviewed-by: NIgor Mammedov <imammedo@redhat.com> Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Showing
想要评论请 注册 或 登录