On 23.02.2022 17:04, Jan Beulich wrote:
> Conditionalize it and its uses accordingly. The main goal though is to
> demonstrate that x86's p2m_teardown() is now empty when !HVM, which in
> particular means the last remaining use of p2m_lock() in this cases goes
> away.
>
> Signed-off-by: Jan Beulich <[email protected]>
> Reviewed-by: Tamas K Lengyel <[email protected]>
> Reviewed-by: George Dunlap <[email protected]>
Forgot to add here:
---
v2: Re-base (drop clearing of field in getdomaininfo()).
Jan
> ---
> I was on the edge of introducing a helper for atomic_read(&d->shr_pages)
> but decided against because of dump_domains() not being able to use it
> sensibly (I really want to omit the output field altogether there when
> !MEM_SHARING).
>
> --- a/xen/arch/x86/mm/p2m-basic.c
> +++ b/xen/arch/x86/mm/p2m-basic.c
> @@ -159,7 +159,6 @@ void p2m_teardown(struct p2m_domain *p2m
> {
> #ifdef CONFIG_HVM
> struct page_info *pg;
> -#endif
> struct domain *d;
>
> if ( !p2m )
> @@ -169,16 +168,17 @@ void p2m_teardown(struct p2m_domain *p2m
>
> p2m_lock(p2m);
>
> +#ifdef CONFIG_MEM_SHARING
> ASSERT(atomic_read(&d->shr_pages) == 0);
> +#endif
>
> -#ifdef CONFIG_HVM
> p2m->phys_table = pagetable_null();
>
> while ( (pg = page_list_remove_head(&p2m->pages)) )
> d->arch.paging.free_page(d, pg);
> -#endif
>
> p2m_unlock(p2m);
> +#endif
> }
>
> void p2m_final_teardown(struct domain *d)
> --- a/xen/common/domctl.c
> +++ b/xen/common/domctl.c
> @@ -109,7 +109,9 @@ void getdomaininfo(struct domain *d, str
> info->tot_pages = domain_tot_pages(d);
> info->max_pages = d->max_pages;
> info->outstanding_pages = d->outstanding_pages;
> +#ifdef CONFIG_MEM_SHARING
> info->shr_pages = atomic_read(&d->shr_pages);
> +#endif
> info->paged_pages = atomic_read(&d->paged_pages);
> info->shared_info_frame =
> gfn_x(mfn_to_gfn(d, _mfn(virt_to_mfn(d->shared_info))));
> --- a/xen/common/keyhandler.c
> +++ b/xen/common/keyhandler.c
> @@ -274,9 +274,16 @@ static void dump_domains(unsigned char k
> printk(" refcnt=%d dying=%d pause_count=%d\n",
> atomic_read(&d->refcnt), d->is_dying,
> atomic_read(&d->pause_count));
> - printk(" nr_pages=%d xenheap_pages=%d shared_pages=%u
> paged_pages=%u "
> - "dirty_cpus={%*pbl} max_pages=%u\n",
> - domain_tot_pages(d), d->xenheap_pages,
> atomic_read(&d->shr_pages),
> + printk(" nr_pages=%u xenheap_pages=%u"
> +#ifdef CONFIG_MEM_SHARING
> + " shared_pages=%u"
> +#endif
> + " paged_pages=%u"
> + " dirty_cpus={%*pbl} max_pages=%u\n",
> + domain_tot_pages(d), d->xenheap_pages,
> +#ifdef CONFIG_MEM_SHARING
> + atomic_read(&d->shr_pages),
> +#endif
> atomic_read(&d->paged_pages), CPUMASK_PR(d->dirty_cpumask),
> d->max_pages);
> printk(" handle=%02x%02x%02x%02x-%02x%02x-%02x%02x-"
> --- a/xen/include/xen/sched.h
> +++ b/xen/include/xen/sched.h
> @@ -385,7 +385,11 @@ struct domain
> unsigned int outstanding_pages; /* pages claimed but not possessed */
> unsigned int max_pages; /* maximum value for
> domain_tot_pages() */
> unsigned int extra_pages; /* pages not included in
> domain_tot_pages() */
> +
> +#ifdef CONFIG_MEM_SHARING
> atomic_t shr_pages; /* shared pages */
> +#endif
> +
> atomic_t paged_pages; /* paged-out pages */
>
> /* Scheduling. */
>
>
