On 07/19/2010 02:33 AM, Gleb Natapov wrote:
On Mon, Jul 19, 2010 at 08:28:02AM +0100, Richard W.M. Jones wrote:
On Mon, Jul 19, 2010 at 09:23:56AM +0300, Gleb Natapov wrote:
That what I am warring about too. If we are adding device we have to be
sure such device can actually exist on real hw too otherwise we may have
problems later.
I don't understand why the constraints of real h/w have anything to do
with this. Can you explain?
Each time we do something not architectural it cause us troubles later.
So constraints of real h/w is our constrains to.
Your constraints are purely artificial.
There are plenty of places that something like fw_cfg could live and
still do DMA. It can directly hang off of the Southbridge. It doesn't
necessary need to be connected to the ISA/LPC buses.
Buses exist to multiplex I/O devices because of limited wiring space on
motherboards. There's no reason we need to constrain ourselves to
minimize the number of virtual wires we emulate.
Regards,
Anthony Liguori
