tree b2d1da458c919c4e78b6f3cb65a89f8cce15cd45
parent ae4c51a50c990d6feba7058c181dc8f22ca5f1d8
author Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> 1532077305 +0300
committer Boris Ostrovsky <boris.ostrovsky@oracle.com> 1532660714 -0400

xen/grant-table: Allow allocating buffers suitable for DMA

Extend grant table module API to allow allocating buffers that can
be used for DMA operations and mapping foreign grant references
on top of those.
The resulting buffer is similar to the one allocated by the balloon
driver in that proper memory reservation is made by
({increase|decrease}_reservation and VA mappings are updated if
needed).
This is useful for sharing foreign buffers with HW drivers which
cannot work with scattered buffers provided by the balloon driver,
but require DMAable memory instead.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>