Re: [PATCH] compat: add a little bit of description to xlat.lst

[Wei Liu <wl@xxxxxxx>]

On Thu, Jul 16, 2020 at 02:21:33PM +0200, Jan Beulich wrote:
> Requested-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Acked-by: Wei Liu <wl@xxxxxxx>

This is much appreciated.

> 
> --- a/xen/include/xlat.lst
> +++ b/xen/include/xlat.lst
> @@ -1,3 +1,22 @@
> +# There are a few fundamentally different strategies for handling compat
> +# (sub-)hypercalls:
> +#
> +# 1) Wrap a translation layer around the native hypercall. Structures 
> involved
> +# in this model should use translation (xlat) macros generated by adding
> +# !-prefixed lines here.
> +#
> +# 2) Compile the entire hypercall function a second time, arranging for the
> +# compat structures to get used in place of the native ones. There are no 
> xlat
> +# macros involved here, all that's needed are correctly translated 
> structures.
> +#
> +# 3) Adhoc translation, which may or may not involve adding entries here.
> +#
> +# 4) Any mixture of the above.
> +#
> +# In all models any structures re-used in their native form should have
> +# ?-mark prefixed lines added here, with the resulting checking macros 
> invoked
> +# somewhere in the code handling the hypercall or its translation.
> +#
>  # First column indicator:
>  # ! - needs translation
>  # ? - needs checking