Re: [PATCH 05/10] xen/arm: introduce alloc_staticmem_pages

[Julien Grall <julien@xxxxxxx>]

Hi Jan,

On 18/05/2021 08:24, Jan Beulich wrote:
> On 18.05.2021 07:21, Penny Zheng wrote:
> > +         * to PGC_state_inuse.
> > +         */
> > +        pg[i].count_info = (pg[i].count_info & PGC_reserved) | PGC_state_inuse;
> > +        /* Initialise fields which have other uses for free pages. */
> > +        pg[i].u.inuse.type_info = 0;
> > +        page_set_owner(&pg[i], NULL);
> > +
> > +        /*
> > +         * Ensure cache and RAM are consistent for platforms where the
> > +         * guest can control its own visibility of/through the cache.
> > +         */
> > +        flush_page_to_ram(mfn_x(page_to_mfn(&pg[i])),
> > +                            !(memflags & MEMF_no_icache_flush));
> > +    }
> > +
> > +    if ( need_tlbflush )
> > +        filtered_flush_tlb_mask(tlbflush_timestamp);
> With reserved pages dedicated to a specific domain, in how far is it
> possible that stale mappings from a prior use can still be around,
> making such TLB flushing necessary?
I would rather not make the assumption. I can see future where we just 
want to allocate memory from a static pool that may be shared with 
multiple domains.
Cheers,

--
Julien Grall