[PATCH v2 0/2] common: XSA-327 follow-up

[Jan Beulich <jbeulich@suse.com>]

There are a few largely cosmetic things that were discussed in the
context of the XSA, but which weren't really XSA material.

1: common: map_vcpu_info() cosmetics
2: evtchn/fifo: don't enforce higher than necessary alignment

I realize both changes are controversial. For the first one
discussion was about the choice of error code. Neither EINVAL nor
EFAULT represent the fact that it is a choice of implementation
to not support mis-aligned structures. If ENXIO isn't liked, the
best I can suggest are EOPNOTSUPP or (as previously suggested)
EPERM. I think it ought to be possible to settle on an error
code everyone can live with.

For the second one the question was whether the relaxation is
useful to do. The original reason for wanting to make the change
remains: The original code here should not be used as an excuse
to introduce similar over-alignment requirements elsewhere. I
can live with the change getting rejected, but if so I'd like to
request that some alternative be submitted to ensure that the
immediate goal can still be reached.

Jan