Re: [Qemu-devel] Re: [RFC PATCH] AMD IOMMU emulation

[Eduard - Gabriel Munteanu]

On Tue, May 25, 2010 at 10:39:22AM +0200, Joerg Roedel wrote:
> On Mon, May 24, 2010 at 08:10:16PM +0000, Blue Swirl wrote:
> > On Mon, May 24, 2010 at 3:40 PM, Joerg Roedel <address@hidden> wrote:
> > >> +
> > >> +#define MMIO_SIZE ? ? ? ? ? ? ? 0x2028
> > >
> > > This size should be a power-of-two value. In this case probably 0x4000.
> > 
> > Not really, the devices can reserve regions of any size. There were
> > some implementation deficiencies in earlier versions of QEMU, where
> > the whole page would be reserved anyway, but this limitation has been
> > removed long time ago.
> 
> The drivers for AMD IOMMU expect that to be 0x4000. At least the Linux
> driver maps the MMIO region with this size. So the emulation should
> reserve this amount of MMIO space too.
> 
>       Joerg

Yeah, I'll change that, since I already reserve 0x4000 bytes in SeaBIOS
for it (I did that to deal with the 16 KiB alignment requirement).


        Eduard