[Xen-devel] [PATCH v3 04/20] xen/grant: Introduce helpers to split a page into grant

Julien Grall julien.grall at citrix.com
Fri Aug 28 07:29:19 PDT 2015


Hi David,

On 20/08/15 10:51, David Vrabel wrote:
> On 07/08/15 17:46, Julien Grall wrote:
>> Currently, a grant is always based on the Xen page granularity (i.e
>> 4KB). When Linux is using a different page granularity, a single page
>> will be split between multiple grants.
>>
>> The new helpers will be in charge to split the Linux page into grants and
>> call a function given by the caller on each grant.
>>
>> Also provide an helper to count the number of grants within a given
>> contiguous region.
>>
>> Note that the x86/include/asm/xen/page.h is now including
>> xen/interface/grant_table.h rather than xen/grant_table.h. It's
>> necessary because xen/grant_table.h depends on asm/xen/page.h and will
>> break the compilation. Furthermore, only definition in
>> interface/grant_table.h was required.
> 
> Reviewed-by: David Vrabel <david.vrabel at citrix.com>
> But...
> 
>> +/* Helper to get to call fn only on the first "grant chunk" */
>> +static inline void gnttab_one_grant(struct page *page, unsigned int offset,
>> +				    unsigned len, xen_grant_fn_t fn,
>> +				    void *data)
> 
> ...call this gnttab_for_one_grant().

Will rename it on the next version.

Regards,

-- 
Julien Grall



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