Re: [Qemu-devel] [PATCH] virtio-pci: Fix endianness of virtio config

[Benjamin Herrenschmidt]

On Wed, 2012-01-11 at 09:04 +1100, Benjamin Herrenschmidt wrote:
> On Tue, 2012-01-10 at 22:45 +0100, Alexander Graf wrote:
> > Here's the thing that I don't understand. What exactly is breaking for
> > you? I tried -M pseries on a ppc box and on an x86 box and both times
> > was able to see /dev/vda.
> 
> And mount it and use it ? Here I get the capacity wrong if I don't have
> my patch and can't actually boot a distro off it.

Hrm actually, it might well work with Linux regardless because Linux
only ever does 8 bit accesses to the virtio config space.

It's SLOF that breaks because SLOF uses 2 and 4 byte accesses (which are
allowed per spec as far as I can tell) but the spurrious swapping
happening in that case means we lost the byte address invariance.

Cheers,
Ben.