iommu: Add padding to struct iommu_fault

Ease future extensions of struct iommu_fault_page_request and struct
iommu_fault_unrecoverable by adding a few bytes of padding. That way, a
new field can be added to either of these structures by simply introducing
a new flag. To extend it after the size limit is reached, a new fault
reporting structure will have to be negotiated with userspace.

With 56 bytes of padding, the total size of iommu_fault is 64 bytes and
fits in a cache line on a lot of contemporary machines, while providing 16
and 24 bytes of extension to structures iommu_fault_page_request and
iommu_fault_unrecoverable respectively.

Signed-off-by: Jean-Philippe Brucker <[email protected]>
Acked-by: Jacob Pan <[email protected]>
Reviewed-by: Eric Auger <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>

0 files changed, 0 insertions, 0 deletions