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

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Tue, 6 Jul 2021, Michal Orzel wrote:
> 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>

Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> > ---
> >     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);
> > 
>