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

[Peter Maydell]

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

thanks
-- PMM