Re: [PATCH v1 3/4] xen: arm: Move the functions of domain_page to MMU specific

[Julien Grall <julien@xxxxxxx>]

Hi,

On 02/08/2024 13:14, Ayan Kumar Halder wrote:
> Moved init_domheap_mappings(), map_domain_page_global(),
> unmap_domain_page_global(), map_domain_page(), unmap_domain_page(),
> domain_page_map_to_mfn() to MMU specific folder.
>
> On the top level, we have added stubs which will invoke the
> MMU specific equivalent of these functions.
>
> Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>
> ---
>   xen/arch/arm/domain_page.c          | 161 +----------------------
Looking at what's left in domain_page.c, we seem to have just a series 
of stubs:
bool init_domheap_mappings(unsigned int cpu)
{
    return init_domheap_mappings_mm(cpu);
}

void *map_domain_page_global(mfn_t mfn)
{
    return map_domain_page_global_mm(mfn);
}

void unmap_domain_page_global(const void *ptr)
{
    return unmap_domain_page_global_mm(ptr);
}

/* Map a page of domheap memory */
void *map_domain_page(mfn_t mfn)
{
    return map_domain_page_mm(mfn);
}

/* Release a mapping taken with map_domain_page() */
void unmap_domain_page(const void *ptr)
{
    return unmap_domain_page_mm(ptr);
}

mfn_t domain_page_map_to_mfn(const void *ptr)
{
    return domain_page_map_to_mfn_mm(ptr);
}

The indirection seems unnecessary to me. What about renaming 
arch/arm/domain_page.c to arch/arm/mmu/domain_page.c? Then, for the MMU 
you can implement unmap_domain_page() & co rather than suffixed _mm ones.
Cheers,

--
Julien Grall