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

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!

  Thomas