Re: [SeaBIOS] [PATCH v2 07/22] virtio: find version 1.0 virtio capabilities

[Michael S. Tsirkin]

On Wed, Jul 01, 2015 at 02:49:54PM +0200, Gerd Hoffmann wrote:
> Hi,
> > > Yes, seabios always allocates both mem and io.
> >
> > What if it can't? E.g. too many devices.
>
> First tries to move 64bit bars above 64g.  Guess we better should
> exclude virtio devices here (like we do for xhci already).

Why? You can use config capability.
> Failing that it'll panic.
>
> cheers,
>   Gerd

IO can't well go above 4G :) So eventually we'll make these express
devices.  For express the spec explicitly says devices must still work
if IO is disabled. At that point maybe teaching bios to disable
IO and keep working will have value.