Hi Michal,
On 17/05/2022 08:14, Michal Orzel wrote:
On 16.05.2022 12:19, Julien Grall wrote:
Hi Michal,
On 06/05/2022 10:42, Michal Orzel wrote:
Modify macros to evaluate all the arguments and make sure the arguments
are evaluated only once. Introduce following intermediate macros:
gnttab_status_gfn_, gnttab_shared_gfn_ that do not take domain as a
parameter. These are to be used locally and allow us to avoid passing
NULL from gnttab_get_frame_gfn to the respective macros (without _ suffix).
Make use of a domain parameter from gnttab_shared_gfn and gnttab_status_gfn
by adding an ASSERT.
Signed-off-by: Michal Orzel <[email protected]>
Most of the helpers below are going to disappear with Oleksandr latest work
(see [1]).
Looking at Oleksandr's patch, I think only gnttab_set_frame_gfn() would end up
to use one of the macro parameters twice. So I would like to suggest to chat
with Oleksandr if we can tweak his patch (can be done on commit) or we rebase
this patch on top of his work.
Cheers,
[1]
https://lore.kernel.org/xen-devel/[email protected]/
By looking at Oleksandr patch:
1. there are 2 macros: gnttab_set_frame_gfn, gnttab_need_iommu_mapping that use
one of the macro parameters twice.
2. gnttab_get_frame_gfn still passes NULL as a domain parameter to
gnttab_shared_gfn/gnttab_status_gfn that do not evaluate domain parameter
I agree that point 1 could be fixed on commit but point 2 requires in my
opinion adding intermediate macros to avoid passing NULL (just like I did).
Ok. I think we could avoid the intermediate macros by implementing the
helpers the other way around. I.e gnttab_{status}_gfn() call
gnttab_get_frame_gfn().
As this would require more work from Oleksandr, I'm ok to rebase my patch on
top of his work once merged.
Thanks!
Cheers,
--
Julien Grall
