Re: [Qemu-devel] [PATCH v3 5/5] Enable fw_cfg DMA interface for x86

[Peter Maydell]

On 18 September 2015 at 11:58, Gerd Hoffmann <address@hidden> wrote:
>   Hi,
>
>> -    fw_cfg = fw_cfg_init_io(BIOS_CFG_IOPORT);
>> +    fw_cfg = fw_cfg_init_io_dma(BIOS_CFG_IOPORT, BIOS_CFG_IOPORT + 4, as);
>
>> +    as = g_malloc(sizeof(*as));
>> +    address_space_init(as, ram_below_4g, "pc.as");
>> +    fw_cfg = bochs_bios_init(as);
>
> I think we can use address_space_memory on x86 too (and can remove the
> AddressSpace argument to fw_cfg_init_io_dma).

I would prefer to keep the AS argument to fw_cfg_init_io_dma().
Random devices shouldn't have their own ideas about what buses
they're plugged into to do DMA (which is effectively what this
is doing) -- the board should be responsible for wiring them
up appropriately.

thanks
-- PMM