Re: [Qemu-arm] [PATCH/RFC 3/5] hw/arm/virt: Allow dynamic sysbus devices again

[Geert Uytterhoeven]

Hi Peter,

On Fri, Feb 9, 2018 at 4:27 PM, Peter Maydell <address@hidden> wrote:
> On 9 February 2018 at 15:17, Geert Uytterhoeven <address@hidden> wrote:
>> Allow the instantation of generic dynamic sysbus devices again, without
>> the need to create a new device-specific vfio type.
>>
>> This is a partial revert of commit  6f2062b9758ebc64 ("hw/arm/virt:
>> Allow only supported dynamic sysbus devices").
>>
>> Not-Yet-Signed-off-by: Geert Uytterhoeven <address@hidden>
>> ---
>>  hw/arm/virt.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
>> index b334c82edae9fb1f..fa83784fc08ed076 100644
>> --- a/hw/arm/virt.c
>> +++ b/hw/arm/virt.c
>> @@ -1596,6 +1596,7 @@ static void virt_machine_class_init(ObjectClass *oc, 
>> void *data)
>>      mc->max_cpus = 255;
>>      machine_class_allow_dynamic_sysbus_dev(mc, TYPE_VFIO_CALXEDA_XGMAC);
>>      machine_class_allow_dynamic_sysbus_dev(mc, TYPE_VFIO_AMD_XGBE);
>> +    machine_class_allow_dynamic_sysbus_dev(mc, TYPE_SYS_BUS_DEVICE);
>>      mc->block_default_type = IF_VIRTIO;
>>      mc->no_cdrom = 1;
>>      mc->pci_allow_0_address = true;
>
> This needs a lot of justification. Dynamic sysbus is not supposed
> to be for plugging any random sysbus device in, it's for vfio,
> which needs special casing anyway to work right. (Overall it's

Sure. Is there a way to limit this to vfio devices?

> a terrible hack -- in an ideal world all vfio would use pci
> or another probeable bus.)

What about vfio-platform, which is my use case?
On DT-based systems, platform devices are described very well in DT (even
better than what's provided by probing PCI IDs and BARs ;-)

Thanks!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- address@hidden

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds