On 4/4/19 4:19 PM, Thomas Huth wrote: > On 04/04/2019 15.29, Philippe Mathieu-Daudé wrote: >> On 4/4/19 12:07 PM, Paolo Bonzini wrote: >>> On 04/04/19 09:14, Thomas Huth wrote: >>>> The i8042 PS/2 controller is part of the chipset on the motherboard. >>>> It is instantiated by the machine init code, and it does not make sense >>>> to allow the user to plug an additional i8042 in any of the free ISA slots. >>>> Thus let's mark the device with user_creatable = false. >>>> >>>> Signed-off-by: Thomas Huth <th...@redhat.com> >>>> --- >>>> hw/input/pckbd.c | 2 ++ >>>> 1 file changed, 2 insertions(+) >>> >>> user_creatable is not for devices that are not pluggable in real life; >>> it is for devices that crash QEMU (!) or always fail if plugged by the user. > > ... hmm, but presenting devices to the user that are clearly not > intended for direct use is also not very nice, is it? > >>> So the question to ask is: would it make sense, and especially work, to >>> add an i8042 to machines that do have an ISA bridge (for example the Alpha?) > > I don't think so. It is a device that is supposed to be part of the > chipset on the motherboard, so operating systems certainly don't know > how to use this device on other machines. > > And at least some part of the device have to be set up in source code > (see e.g. i8042_setup_a20_line() ...). > >> Correct me if I'm wrong but it seems no machine directly use a 8042 on a >> ISA bus, it is always part of a SuperIO chipset. It is not reflected in >> the code (in particular the X86 machines, but I'm working on cleaning this). > > What about the "isa_create_simple(isa_bus, TYPE_I8042)" in mips_r4k.c ?
There is a comment at the top of the file: " All peripherial devices are attached to this "bus" with the standard PC ISA addresses." So IMO this setup is definitively modelable by an instance of the TYPE_ISA_SUPERIO abstract device. At a quick look the r4k has no parallel port and 4 uarts, so I'd add a such model internal to mips_r4k.c (see fdc37m81x_class_init()). >>>> diff --git a/hw/input/pckbd.c b/hw/input/pckbd.c >>>> index 47a606f5e3..af393818fc 100644 >>>> --- a/hw/input/pckbd.c >>>> +++ b/hw/input/pckbd.c >>>> @@ -568,6 +568,8 @@ static void i8042_class_initfn(ObjectClass *klass, >>>> void *data) >>>> dc->realize = i8042_realizefn; >>>> dc->vmsd = &vmstate_kbd_isa; >>>> set_bit(DEVICE_CATEGORY_INPUT, dc->categories); >>>> + /* i8042 is a device on the motherboard, and not pluggable by the >>>> user */ >> >> I'm not sure the comment is accurate, maybe "ISA i8042 are provided by >> Super I/O devices"? > > Fine for me, too ... but what about mips_r4k in that case? > > Thomas >
