Re: [PATCH v2] hw/sparc64/sun4u: Mark unusable PCI busses as full to ease device plugging

On 08/06/2026 23.29, Mark Cave-Ayland wrote:
> On 08/06/2026 09:26, Michael Tokarev wrote:
> 
>> On 30.04.2026 12:50, Thomas Huth wrote:
>>> On 09/03/2026 19.14, Thomas Huth wrote:
>>>> From: Thomas Huth <[email protected]>
>>>>
>>>> When trying to plug a PCI device to a Sparc64 machine, you currently
>>>> have to specify the right bus ("bus=pciB"), otherwise you get this error:
>>>>
>>>>   $ qemu-system-sparc64 -device virtio-scsi-pci
>>>>   qemu-system-sparc64: -device virtio-scsi-pci: PCI: no slot/function
>>>>   available for virtio-scsi-pci, all in use or reserved
>>>>
>>>> This is quite annoying for the unexperienced users, and it also breaks
>>>> e.g. the iotests ("make check-block") when running with qemu-system- 
>>>> sparc64.
>>>>
>>>> Mark the non-usable PCI busses as full now, so that QEMU can automatically
>>>> plug new PCI devices to the right "pciB" bus.
>>>>
>>>> Signed-off-by: Thomas Huth <[email protected]>
>>>> ---
>>>>   v2: Do the change in the machine code, not in the sabre device
>>>>
>>>>   hw/sparc64/sun4u.c | 7 +++++++
>>>>   1 file changed, 7 insertions(+)
>>>>
>>>> diff --git a/hw/sparc64/sun4u.c b/hw/sparc64/sun4u.c
>>>> index b8bda1eb816..37539535c6c 100644
>>>> --- a/hw/sparc64/sun4u.c
>>>> +++ b/hw/sparc64/sun4u.c
>>>> @@ -723,6 +723,13 @@ static void sun4uv_init(MemoryRegion 
>>>> *address_space_mem,
>>>>       fw_cfg_add_i16(fw_cfg, FW_CFG_SPARC64_DEPTH, graphic_depth);
>>>>       qemu_register_boot_set(fw_cfg_boot_set, fw_cfg);
>>>> +
>>>> +    /*
>>>> +     * Mark internal PCI busses as full so that the plugging of additional
>>>> +     * PCI devices happens on the right bus that still has free slots:
>>>> +     */
>>>> +    qbus_mark_full(&pci_bus->qbus);
>>>> +    qbus_mark_full(&pci_busA->qbus);
>>>>   }
>>>>   enum {
>>>
>>> Friendly ping!
>>
>> This, being a simple change, somehow has not been reviewed still, so
>> it's sitting in the queue...
> 
> Yes, apologies - I've been absolutely flat out recently, and I've got a note 
> to take a look at this and Peter's patch as soon as I can.
> 
> Is this fixing an urgent issue with "make check-block" or similar?

It's not urgent since this has been broken forever, but yes, it fixes "make 
check-block" for the case where sparc64 is the only available target during 
"configure --target-list=sparc64-softmmu" and thus the iotests run with 
qemu-system-sparc64.

  Thomas