target/sbc: Add DIF TYPE1+TYPE3 read/write verify emulation

This patch adds support for DIF read/write verify emulation
for TARGET_DIF_TYPE1_PROT + TARGET_DIF_TYPE3_PROT operation.

This includes sbc_dif_verify_write() + sbc_dif_verify_read()
calls accessable by backend drivers to perform DIF verify
for SGL based data and protection information.

Also included is sbc_dif_copy_prot() logic to copy protection
information to/from backend provided protection SGLs.

Based on scsi_debug.c DIF TYPE1+TYPE3 emulation.

v2 changes:
  - Select CRC_T10DIF for TARGET_CORE in Kconfig (Fengguang)
  - Drop IP checksum logic from sbc_dif_v1_verify (MKP)
  - Fix offset on app_tag = 0xffff in sbc_dif_verify_read()

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 0dc2745b9b18..7020e33e742e 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -73,6 +73,10 @@ sense_reason_t sbc_execute_unmap(struct se_cmd *cmd,
         sense_reason_t (*do_unmap_fn)(struct se_cmd *cmd, void *priv,
                                       sector_t lba, sector_t nolb),
         void *priv);
+sense_reason_t  sbc_dif_verify_write(struct se_cmd *, sector_t, unsigned int,
+                                     unsigned int, struct scatterlist *, int);
+sense_reason_t  sbc_dif_verify_read(struct se_cmd *, sector_t, unsigned int,
+                                    unsigned int, struct scatterlist *, int);
 
 void    transport_set_vpd_proto_id(struct t10_vpd *, unsigned char *);
 int     transport_set_vpd_assoc(struct t10_vpd *, unsigned char *);