Shuhei Matsumoto 8696cd4288 dif: Add seed value for guard to avoid 0 in case of all zero data.
Allow user to add seed value for guard compuation to DIF context.
This will avoid the guard being zero in case of all zero data.

NVMe controller doesn't support seed value for guard computation
explicitly, and hence if we want to use such a seed value in
NVMe controller, we have to format metadata more than 8 byte,
and add seed value into the reserved metadata field.

But some popular iSCSI/FC HBAs and SAS controllers have supported
seed value for guard computation, and so supporting seed value
in the SPDK DIF library is very helpful for some use cases.

Hence this patch makes the DIF library possible to specify seed
value for those use cases.

Change-Id: I7e9e87cb441bf263e64605c7820409fdc22dd977
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-on: https://review.gerrithub.io/c/444334
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: wuzhouhui <wuzhouhui@kingsoft.com>
2019-02-22 17:52:51 +00:00
..
2017-08-02 19:47:35 -04:00
2018-12-06 22:25:09 +00:00