Re: [Qemu-devel] [RFC PATCH 1/4] I440: Allow adding sysbus devices with -device on I440

[Eduardo Habkost]

On Fri, Mar 17, 2017 at 07:29:14PM +0800, Lan Tianyu wrote:
> From: Chao Gao <address@hidden>
> 
> xen-viommu will be a sysbus device and the device model will
> be enabled via "-device" parameter.
> 
> Signed-off-by: Chao Gao <address@hidden>
> Signed-off-by: Lan Tianyu <address@hidden>

I'm worried about the bugs we may expose by accepting all the
other sysbus devices in the command-line in addition to
xen-viommu.

I am working on a RFC to replace "has_dynamic_sysbus" with a
whitelist of sysbus device classes. This way we could enable only
xen-viommu on i440fx, instead of suddenly enabling all sysbus
devices just because of xen-viommu.

> ---
>  hw/i386/pc_piix.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index a07dc81..3289593 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -436,6 +436,7 @@ static void pc_i440fx_machine_options(MachineClass *m)
>      m->hot_add_cpu = pc_hot_add_cpu;
>      m->default_machine_opts = "firmware=bios-256k.bin";
>      m->default_display = "std";
> +    m->has_dynamic_sysbus = true;
>  }
>  
>  static void pc_i440fx_2_7_machine_options(MachineClass *m)
> -- 
> 1.8.3.1
> 

-- 
Eduardo