Re: [PATCH v3 08/20] xen/riscv: add new p2m types and helper macros for type classification

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 8/4/25 4:16 PM, Jan Beulich wrote:

> On 31.07.2025 17:58, Oleksii Kurochko wrote:
> > - Extended p2m_type_t with additional types: p2m_mmio_direct,
> >   p2m_grant_map_{rw,ro}.
> > - Added macros to classify memory types: P2M_RAM_TYPES, P2M_GRANT_TYPES.
> > - Introduced helper predicates: p2m_is_ram(), p2m_is_any_ram().
> > - Define p2m_mmio_direct to tell handle_passthrough_prop() from common
> >   code how to map device memory.
> >
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> >       
> Almost ready to be acked, except for ...
>
> > --- a/xen/arch/riscv/include/asm/p2m.h
> > +++ b/xen/arch/riscv/include/asm/p2m.h
> > @@ -62,8 +62,30 @@ struct p2m_domain {
> >  typedef enum {
> >      p2m_invalid = 0,    /* Nothing mapped here */
> >      p2m_ram_rw,         /* Normal read/write domain RAM */
> > +    p2m_mmio_direct_io, /* Read/write mapping of genuine Device MMIO area,
> > +                           PTE_PBMT_IO will be used for such mappings */
> > +    p2m_ext_storage,    /* Following types'll be stored outsude PTE bits: */
> > +    p2m_grant_map_rw,   /* Read/write grant mapping */
> > +    p2m_grant_map_ro,   /* Read-only grant mapping */
> >  } p2m_type_t;
> >  
> > +#define p2m_mmio_direct p2m_mmio_direct_io
> >       
> ... this (see reply to patch 09).
>
> > +/* We use bitmaps and mask to handle groups of types */
> > +#define p2m_to_mask(t_) BIT(t_, UL)
> >       
> I notice that you moved the underscore to the back of the parameters,
> compared to how Arm has it. I wonder though: What use are these
> underscores in the first place, here and below? (There are macros where
> conflicts could arise, but the ones here don't fall in that group,
> afaict.)
>     
Good point, there is really no name conflicts here, so underscore could
be just dropped.

~ Oleksii