On Fri, Sep 22, 2023 at 07:07:40PM +0100, Robin Murphy wrote:
virtio isn't setting ops->pgsize_bitmap for the sake of direct mappingsWell it can't quite do that since it doesn't know the geometry - it
either; it sets it once it's discovered any instance, since apparently it's
assuming that all instances must support identical page sizes, and thus once
it's seen one it can work "normally" per the core code's assumptions. It's
also I think the only driver which has a "finalise" bodge but*can* still
properly support map-before-attach, by virtue of having to replay mappings
to every new endpoint anyway.
all is sort of guessing and hoping it doesn't explode on replay. If it
knows the geometry it wouldn't need finalize...