"Michael S. Tsirkin" <m...@redhat.com> writes: > On Wed, Apr 13, 2016 at 10:59:35AM +0200, Markus Armbruster wrote: >> I have a hard time coming up with realistic unclean breakage. > > The issue is that Linux is now exposing fw cfg to userspace. > So it's use is about to expand significantly. > > This is what I am trying to prevent: > - in 2016, users build a guest using a path XXX outside opt. > there's a warning on host, but it is not noticed.
Amend: The guest treats path XXX as optional. > - in 2020, qemu starts using path XXX for internal purposes. > - using guest from 2016 now breaks uncleanly on this new qemu Amend: when we're not specifying the optional path XXX with -fw_cfg. > since guest thinks it's talking to the external tool. Okay, that's a much more plausible scenario. The question remains whether preventing it justifies the compat break and the additional interface complexity.