Re: [PATCH v4 07/18] xen/riscv: add new p2m types and helper macros for type classification

[Jan Beulich <jbeulich@xxxxxxxx>]

On 17.09.2025 23:55, Oleksii Kurochko wrote:
> - Extended p2m_type_t with additional types: p2m_mmio_direct,
>   p2m_ext_storage.
> - Added macros to classify memory types: P2M_RAM_TYPES.
> - Introduced helper predicates: p2m_is_ram(), p2m_is_any_ram().
> - Introduce arch_dt_passthrough() to tell handle_passthrough_prop()
>   from common code how to map device memory.
> - Introduce p2m_first_external for detection for relational operations
>   with p2m type which is stored outside P2M's PTE bits.
> 
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> ---
> Changes in V4:
>  - Drop underscode in p2m_to_mask()'s argument and for other similar helpers.

Except that ...

> --- a/xen/arch/riscv/include/asm/p2m.h
> +++ b/xen/arch/riscv/include/asm/p2m.h
> @@ -64,8 +64,29 @@ 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: */
> +
> +    /* Sentinel — not a real type, just a marker for comparison */
> +    p2m_first_external = p2m_ext_storage,
>  } p2m_type_t;
>  
> +static inline p2m_type_t arch_dt_passthrough_p2m_type(void)
> +{
> +    return p2m_mmio_direct_io;
> +}
> +
> +/* We use bitmaps and mask to handle groups of types */
> +#define p2m_to_mask(t) BIT(t, UL)
> +
> +/* RAM types, which map to real machine frames */
> +#define P2M_RAM_TYPES (p2m_to_mask(p2m_ram_rw))
> +
> +/* Useful predicates */
> +#define p2m_is_ram(t_) (p2m_to_mask(t_) & P2M_RAM_TYPES)
> +#define p2m_is_any_ram(t_) (p2m_to_mask(t_) & P2M_RAM_TYPES)

... they're still present here. With these also dropped:
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>

Jan