On 04.01.2022 10:48, Jan Beulich wrote:
> Avoid recurring MFN -> page or page -> MFN translations. Drop the pretty
> pointless local variable "p". Make sure the MFN logged in a debugging
> error message is actually the offending one. Return negative errno
> values rather than -1 (presently no caller really cares, but imo this
> should change). Adjust style.
>
> Signed-off-by: Jan Beulich <jbeul...@suse.com>
> ---
> v2: Return -errno. Drop exclamation mark from log message.
Ping?
> --- a/xen/arch/x86/mm/p2m-pod.c
> +++ b/xen/arch/x86/mm/p2m-pod.c
> @@ -58,34 +58,27 @@ p2m_pod_cache_add(struct p2m_domain *p2m
> unsigned int order)
> {
> unsigned long i;
> - struct page_info *p;
> struct domain *d = p2m->domain;
> + mfn_t mfn = page_to_mfn(page);
>
> #ifndef NDEBUG
> - mfn_t mfn;
> -
> - mfn = page_to_mfn(page);
> -
> /* Check to make sure this is a contiguous region */
> if ( mfn_x(mfn) & ((1UL << order) - 1) )
> {
> printk("%s: mfn %lx not aligned order %u! (mask %lx)\n",
> __func__, mfn_x(mfn), order, ((1UL << order) - 1));
> - return -1;
> + return -EINVAL;
> }
>
> - for ( i = 0; i < 1UL << order ; i++)
> + for ( i = 0; i < (1UL << order); i++)
> {
> - struct domain * od;
> + const struct domain *od = page_get_owner(page + i);
>
> - p = mfn_to_page(mfn_add(mfn, i));
> - od = page_get_owner(p);
> if ( od != d )
> {
> - printk("%s: mfn %lx expected owner d%d, got owner d%d!\n",
> - __func__, mfn_x(mfn), d->domain_id,
> - od ? od->domain_id : -1);
> - return -1;
> + printk("%s: mfn %lx owner: expected %pd, got %pd\n",
> + __func__, mfn_x(mfn) + i, d, od);
> + return -EACCES;
> }
> }
> #endif
> @@ -98,16 +91,12 @@ p2m_pod_cache_add(struct p2m_domain *p2m
> * promise to provide zero pages. So we scrub pages before using.
> */
> for ( i = 0; i < (1UL << order); i++ )
> - clear_domain_page(mfn_add(page_to_mfn(page), i));
> + clear_domain_page(mfn_add(mfn, i));
>
> /* First, take all pages off the domain list */
> lock_page_alloc(p2m);
> - for ( i = 0; i < 1UL << order ; i++ )
> - {
> - p = page + i;
> - page_list_del(p, &d->page_list);
> - }
> -
> + for ( i = 0; i < (1UL << order); i++ )
> + page_list_del(page + i, &d->page_list);
> unlock_page_alloc(p2m);
>
> /* Then add to the appropriate populate-on-demand list. */
>
>
