Re: [PATCH v7 05/19] xen/riscv: add root page table allocation

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 12/18/25 2:58 PM, Jan Beulich wrote:
> On 16.12.2025 17:55, Oleksii Kurochko wrote:
> > @@ -30,6 +34,11 @@ struct p2m_domain {
> >       /* Pages used to construct the p2m */
> >       struct page_list_head pages;
> >   
> > +    /* The root of the p2m tree. May be concatenated */
> > +    struct page_info *root;
> > +
> > +    struct gstage_mode_desc mode;
> Why would this need a copy (instance) of the struct? Can't this be a
> (const) pointer into the static array that currently is local to
> gstage_mode_detect()? Similarly there max_gstage_mode could be a pointer
> rather than a separate instance of the struct.
Good point. I will take that into account when will deal with TODO.

Thanks.

~ Oleksii

> Yes, there is a connection to ...
>
> > @@ -124,6 +193,24 @@ int p2m_init(struct domain *d)
> >       rwlock_init(&p2m->lock);
> >       INIT_PAGE_LIST_HEAD(&p2m->pages);
> >   
> > +    /*
> > +     * Currently, the infrastructure required to enable CONFIG_HAS_PASSTHROUGH
> > +     * is not ready for RISC-V support.
> > +     *
> > +     * When CONFIG_HAS_PASSTHROUGH=y, p2m->clean_dcache must be properly
> > +     * initialized.
> > +     * At the moment, it defaults to false because the p2m structure is
> > +     * zero-initialized.
> > +     */
> > +#ifdef CONFIG_HAS_PASSTHROUGH
> > +#   error "Add init of p2m->clean_dcache"
> > +#endif
> > +
> > +    /* TODO: don't hardcode used for a domain g-stage mode. */
> > +    p2m->mode.mode = HGATP_MODE_SV39X4;
> > +    p2m->mode.paging_levels = 2;
> > +    safe_strcpy(p2m->mode.name, "Sv39x4");
> ... this TODO, but surely this code could similarly be made reference the
> (then) global array.