The existing code shows the "Bus '%s' is full" message even if name is specified and different from bus->name (i.e. match=0).
The patch excludes unnecessary error message. Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> --- I added traces (trivial, not in the patch) into qbus_find_recursive and run QEMU with the command line below. Without the patch, the output is: bus->name=main-system-bus name=usb1.0 bus_typename=(null) continue bus->name=pci name=usb1.0 bus_typename=(null) continue bus->name=virtio_scsi_pci0.0 name=usb1.0 bus_typename=(null) --- max_dev=1, max_index=1 match=0 qemu-system-ppc64: -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1: Bus 'virtio_scsi_pci0.0' is full bus->name=usb1.0 name=usb1.0 bus_typename=(null) MATCH With the patch, it is: bus->name=main-system-bus name=usb1.0 bus_typename=(null) continue bus->name=pci name=usb1.0 bus_typename=(null) continue bus->name=virtio_scsi_pci0.0 name=usb1.0 bus_typename=(null) continue bus->name=scsi.0 name=usb1.0 bus_typename=(null) continue bus->name=usb1.0 name=usb1.0 bus_typename=(null) MATCH The final behaviour does not change and the requested bus is found but without confusing messages. However I am not sure that is the right thing to continue looking down the bus instead of going to the next sibling. What would the community say? /home/aik/qemu-system-ppc64 -L qemu-ppc64-bios/ -trace events=trace_events -S -name virt-tests-vm1 -nodefaults -chardev stdio,id=char1,signal=off,mux=on -device spapr-vty,id=ser1,chardev=char1 -mon chardev=char1,mode=readline,id=mon1 -device ich9-usb-uhci1,id=usb1,bus=pci -drive file=/home/aik/virtimg/test1,index=0,if=scsi -drive file=/home/aik/virtimg/test2,index=2,if=scsi -device virtio-scsi-pci,id=virtio_scsi_pci0 -drive file=/home/aik/virtimg/test4,if=none,id=virtio-scsi4 -device scsi-hd,drive=virtio-scsi4 -drive file=/home/aik/virtimg/test5,if=none,id=usb2.5 -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1 -m 1024 -machine pseries -nographic -vga none -enable-kvm --- qdev-monitor.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/qdev-monitor.c b/qdev-monitor.c index 9a78ccf..551f81f 100644 --- a/qdev-monitor.c +++ b/qdev-monitor.c @@ -291,11 +291,9 @@ static BusState *qbus_find_recursive(BusState *bus, const char *name, if (name && (strcmp(bus->name, name) != 0)) { match = 0; - } - if (bus_typename && !object_dynamic_cast(OBJECT(bus), bus_typename)) { + } else if (bus_typename && !object_dynamic_cast(OBJECT(bus), bus_typename)) { match = 0; - } - if ((bus_class->max_dev != 0) && (bus_class->max_dev <= bus->max_index)) { + } else if ((bus_class->max_dev != 0) && (bus_class->max_dev <= bus->max_index)) { if (name != NULL) { /* bus was explicitly specified: return an error. */ qerror_report(ERROR_CLASS_GENERIC_ERROR, "Bus '%s' is full", -- 1.7.10.4