[ just back from summer vacation, wading through my backlog ... ]
I feel like it would be up to Gerd as the general SeaBIOS point of contact?
...ah, who is offline for vacation.
We're in freeze right now anyway, so I would think that Gerd and/or Kevin can work out who ought to stage this for a PR when the tree opens again.
As this touches alot of block code I've expected it to go via block tree, therefore I've added my reviewed-by to indicate the fw_cfg / seabios side of things is fine from my point of view. seabios patches are reviewed and ready.
Merging via Phil's fw_cfg tree would make sense too, but Phil probably wants an ack from the block layer guys in that case.