Re: [PATCH v1 5/6] xen/riscv: add new p2m types and helper macros for type classification

[Jan Beulich <jbeulich@xxxxxxxx>]

On 09.05.2025 17:57, Oleksii Kurochko wrote:
> --- a/xen/arch/riscv/include/asm/p2m.h
> +++ b/xen/arch/riscv/include/asm/p2m.h
> @@ -80,8 +80,36 @@ struct p2m_domain {
>  typedef enum {
>      p2m_invalid = 0,    /* Nothing mapped here */
>      p2m_ram_rw,         /* Normal read/write domain RAM */
> +    p2m_ram_ro,         /* Read-only; writes are silently dropped */

This is pretty special a type, which imo better wouldn't be introduced
without there being proper support for it. (I don't suppose RISC-V
hardware alone can effect this type?)

> +    p2m_mmio_direct_dev,/* Read/write mapping of genuine Device MMIO area */
> +    p2m_map_foreign_rw, /* Read/write RAM pages from foreign domain */
> +    p2m_map_foreign_ro, /* Read-only RAM pages from foreign domain */

Aiui you took these from Arm. Looking at its sole use, I'm not convinced
it's used correctly. If it is, the same comment as for p2m_ram_ro above
would apply here, too.

Jan