On 17/10/2019 16.34, Cornelia Huck wrote: > On Thu, 17 Oct 2019 16:21:23 +0200 > Thomas Huth <th...@redhat.com> wrote: > >> There is no USB on s390x, so running qemu-system-s390x with >> "-machine ...,usb=on" is certainly wrong. Emit a warning to make >> the users aware of their misconfiguration. >> >> Signed-off-by: Thomas Huth <th...@redhat.com> >> --- >> After a year or two, we could finally turn this into a hard error, >> but I think we should give the users some time to fix their command >> lines first, so I'm initially only emitting a warning here. >> >> hw/s390x/s390-virtio-ccw.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c >> index d3edeef0ad..af8c4c0daf 100644 >> --- a/hw/s390x/s390-virtio-ccw.c >> +++ b/hw/s390x/s390-virtio-ccw.c >> @@ -243,6 +243,10 @@ static void ccw_init(MachineState *machine) >> VirtualCssBus *css_bus; >> DeviceState *dev; >> >> + if (machine->usb) { >> + warn_report("This machine does not support USB"); > > I'm wondering if this is the only machine type not supporting usb... > if not, how are others handling it?
I think most machines are silently ignoring it, like we did on s390x until now, too. > The usb parsing code in machine.c does not care if usb is even > configured (CONFIG_USB). machine.c is common code, so you can not use CONFIG_USB there. > There's other stuff in there like > igd-passthru, which seems to be x86 specific; probably historical > reasons? IMHO igd-passthru should be moved to the xen machine, which seems to be the only user. Thomas