Re: [Qemu-devel] [RFC][PATCH 08/15] isa: implement isa_is_ioport_assigned via memory_region_find

[Paolo Bonzini <pbonzini@redhat.com>]

Il 06/05/2013 17:02, Jan Kiszka ha scritto:
> On 2013-05-06 16:59, Paolo Bonzini wrote:
>> Il 06/05/2013 16:55, Andreas Färber ha scritto:
>>> Am 06.05.2013 16:26, schrieb Jan Kiszka:
>>>> Move isa_is_ioport_assigned to the ISA core and implement it via a
>>>> memory region lookup. As all IO ports are now directly or indirectly
>>>> registered via the memory API, this becomes possible and will finally
>>>> allow us to drop the ioport tables.
>>>>
>>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>>> ---
>>>>  hw/acpi/piix4.c       |    6 +++---
>>>>  hw/isa/isa-bus.c      |   11 +++++++++++
>>>>  hw/isa/lpc_ich9.c     |    8 ++++----
>>>>  include/exec/ioport.h |    1 -
>>>>  include/hw/isa/isa.h  |    2 ++
>>>>  ioport.c              |    7 -------
>>>>  6 files changed, 20 insertions(+), 15 deletions(-)
>>>>
>>>> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
>>>> index c4af1cc..5955217 100644
>>>> --- a/hw/acpi/piix4.c
>>>> +++ b/hw/acpi/piix4.c
>>>> @@ -386,10 +386,10 @@ static void piix4_pm_machine_ready(Notifier *n, void *opaque)
>>>>      uint8_t *pci_conf;
>>>>  
>>>>      pci_conf = s->dev.config;
>>>> -    pci_conf[0x5f] = (isa_is_ioport_assigned(0x378) ? 0x80 : 0) | 0x10;
>>>> +    pci_conf[0x5f] = (isa_is_ioport_assigned(NULL, 0x378) ? 0x80 : 0) | 0x10;
>>>>      pci_conf[0x63] = 0x60;
>>>> -    pci_conf[0x67] = (isa_is_ioport_assigned(0x3f8) ? 0x08 : 0) |
>>>> -	(isa_is_ioport_assigned(0x2f8) ? 0x90 : 0);
>>>> +    pci_conf[0x67] = (isa_is_ioport_assigned(NULL, 0x3f8) ? 0x08 : 0) |
>>>> +        (isa_is_ioport_assigned(NULL, 0x2f8) ? 0x90 : 0);
>>>>  
>>>>  }
>>>>  
>>>
>>> Is there really no way to access the ISABus from this device? Would be
>>> nice to get rid of global ISA variables and not introduce more
>>> dependencies. :)
>>
>> There's always a way to find the ISABus via QOM:
>>
>>     ISABus *isa_bus = (ISABus *) object_resolve_path_type("", TYPE_ISA_BUS, NULL);
> 
> Err, in what way is this better? It also assumes that there is only one.

I didn't say it is better. :)  Unfortunately, the PIIX4 has these
register on the "wrong" function, ICH9 fixed it.

You could make this take an AddressSpace instead of an ISABus, and use
pci_address_space_io.  The assumption then becomes that the ISA and PM
devices have the same address spaces, which is somewhat hackish but
reasonable.

In fact, with the other new API I have added (address_space_valid), this
would become address_space_valid(pci_address_space_io(dev), 0x2f8, 1)
and similar.  I need to check, but you could remove
isa_is_ioport_assigned completely.

Paolo