Re: [PATCH v5 3/4] xen: arm: Remove mfn_to_gfn() macro

[Michal Orzel <michal.orzel@xxxxxxx>]

On 03.07.2021 19:11, Julien Grall wrote:
> From: Julien Grall <julien.grall@xxxxxxx>
> 
> The current implementation of mfn_to_gfn() is completely bogus and
> there are no plan to implement an M2P on Arm. As there are no more
> users, drop the helper.
> 
s/plan/plans/
> At the same time rework a comment in Arm code that does not make sense.
> 
> Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
> 
> ---
>     Changes in v5:
>         - Rebase to the latest Xen
>         - The patch is now arm only because mfn_to_gmfn() has
>         been dropped on x86 and the arm helper was renamed to
>         mfn_to_gfn().
> 
>     Changes in v4:
>         - Remove acks as the patch is old
> 
>     Changes in v2:
>         - Add Jan's and Stefano's acked-by
> ---
>  xen/include/asm-arm/mm.h | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
> index ded74d29da0c..07c24654a0b6 100644
> --- a/xen/include/asm-arm/mm.h
> +++ b/xen/include/asm-arm/mm.h
> @@ -326,9 +326,8 @@ struct page_info *get_page_from_gva(struct vcpu *v, 
> vaddr_t va,
>  #define SHARED_M2P_ENTRY         (~0UL - 1UL)
>  #define SHARED_M2P(_e)           ((_e) == SHARED_M2P_ENTRY)
>  
> -/* Xen always owns P2M on ARM */
> +/* We don't have a M2P on Arm */
>  #define set_gpfn_from_mfn(mfn, pfn) do { (void) (mfn), (void)(pfn); } while 
> (0)
> -#define mfn_to_gfn(d, mfn) ((void)(d), _gfn(mfn_x(mfn)))
>  
>  /* Arch-specific portion of memory_op hypercall. */
>  long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg);
>