Re: [PATCH 3/5] xen/memory: Fix compat XENMEM_acquire_resource for size requests

[Jan Beulich <jbeulich@xxxxxxxx>]

On 28.07.2020 13:37, Andrew Cooper wrote:
> Copy the nr_frames from the correct structure, so the caller doesn't
> unconditionally receive 0.
Well, no - it does get copied from the correct structure. It's just
that the field doesn't get set properly up front. Otherwise you'll
(a) build in an unchecked assumption that the native and compat
fields match in type and (b) set a bad example for people looking
here and then cloning this code in perhaps a case where (a) is not
even true. If you agree, the alternative change of setting
cmp.mar.nr_frames from nat.mar->nr_frames before the call is

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>

Jan