Re: [PATCH v2 6/6] hw/isa/piix: Resolve redundant TYPE_PIIX3_XEN_DEVICE

[Chuck Zmudzinski <brchuckz@xxxxxxx>]

On 1/6/23 2:08 PM, Chuck Zmudzinski wrote:
> On 1/6/23 7:25 AM, Philippe Mathieu-Daudé wrote:
>> On 6/1/23 12:57, Bernhard Beschow wrote:
>>> 
>>> 
>>> Am 4. Januar 2023 15:35:33 UTC schrieb "Philippe Mathieu-Daudé" 
>>> <philmd@xxxxxxxxxx>:
>>>> +Markus/Thomas
>>>>
>>>> On 4/1/23 15:44, Bernhard Beschow wrote:
>>>>> During the last patches, TYPE_PIIX3_XEN_DEVICE turned into a clone of
>>>>> TYPE_PIIX3_DEVICE. Remove this redundancy.
>>>>>
>>>>> Signed-off-by: Bernhard Beschow <shentey@xxxxxxxxx>
>>>>> ---
>>>>>    hw/i386/pc_piix.c             |  4 +---
>>>>>    hw/isa/piix.c                 | 20 --------------------
>>>>>    include/hw/southbridge/piix.h |  1 -
>>>>>    3 files changed, 1 insertion(+), 24 deletions(-)
>> 
>> 
>>>>>    -static void piix3_xen_class_init(ObjectClass *klass, void *data)
>>>>> -{
>>>>> -    DeviceClass *dc = DEVICE_CLASS(klass);
>>>>> -    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>>>>> -
>>>>> -    k->realize = piix3_realize;
>>>>> -    /* 82371SB PIIX3 PCI-to-ISA bridge (Step A1) */
>>>>> -    k->device_id = PCI_DEVICE_ID_INTEL_82371SB_0;
>>>>> -    dc->vmsd = &vmstate_piix3;
>>>>
>>>> IIUC, since this device is user-creatable, we can't simply remove it
>>>> without going thru the deprecation process.
>>> 
>>> AFAICS this device is actually not user-creatable since dc->user_creatable 
>>> is set to false once in the base class. I think it is safe to remove the 
>>> Xen class unless there are ABI issues.
>> Great news!
> 
> I don't know if this means the device is user-creatable:
> 
> chuckz@bullseye:~$ qemu-system-i386 -device piix3-ide-xen,help
> piix3-ide-xen options:
>   addr=<int32>           - Slot and optional function number, example: 06.0 
> or 06 (default: -1)
>   failover_pair_id=<str>
>   multifunction=<bool>   - on/off (default: false)
>   rombar=<uint32>        -  (default: 1)
>   romfile=<str>
>   x-pcie-extcap-init=<bool> - on/off (default: true)
>   x-pcie-lnksta-dllla=<bool> - on/off (default: true)
> 
> Today I am running qemu-5.2 on Debian 11, so this output is for
> qemu 5.2, and that version of qemu has a piix3-ide-xen device.
> Is that this same device that is being removed? If so, it seems to
> me that at least as of qemu 5.2, the device was user-creatable.
> 
> Chuck

Good news! It looks the device was removed as user-creatable since version 5.2:

chuckz@debian:~$ qemu-system-i386-7.50 -device help | grep piix
name "piix3-usb-uhci", bus PCI
name "piix4-usb-uhci", bus PCI
name "piix3-ide", bus PCI
name "piix4-ide", bus PCI
chuckz@debian:~$ qemu-system-i386-7.50-bernhard-v2 -device help | grep piix
name "piix3-usb-uhci", bus PCI
name "piix4-usb-uhci", bus PCI
name "piix3-ide", bus PCI
name "piix4-ide", bus PCI
chuckz@debian:~$

The piix3-ide-xen device is not present either with or without Bernhard's 
patches
for current qemu 7.50, the development version for qemu 8.0

Cheers,

Chuck