Re: [PATCH for-4.19] gnttab: fix compat query-size handling

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Tue, Jun 25, 2024 at 09:30:07AM +0200, Jan Beulich wrote:
> The odd DEFINE_XEN_GUEST_HANDLE(), inconsistent with all other similar
> constructs, should have caught my attention. Turns out it was needed for
> the build to succeed merely because the corresponding #ifndef had a
> typo. That typo in turn broke compat mode guests, by having query-size
> requests of theirs wire into the domain_crash() at the bottom of the
> switch().
> 
> Fixes: 8c3bb4d8ce3f ("xen/gnttab: Perform compat/native gnttab_query_size 
> check")
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

> ---
> Looks like set-version is similarly missing in the set of structures
> checked, but I'm pretty sure that we will now want to defer taking care
> of that until after 4.20 was branched.

If we have to backport the fix anyway, we might as well consider
taking it now.

Thanks, Roger.