IB/rdmavt: Add support for ib_map_mr_sg

This implements the device specific function needed by the verbs
API function ib_map_mr_sg().

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/sw/rdmavt/vt.c b/drivers/infiniband/sw/rdmavt/vt.c
index 89fe967..d430c2f 100644
--- a/drivers/infiniband/sw/rdmavt/vt.c
+++ b/drivers/infiniband/sw/rdmavt/vt.c
@@ -370,6 +370,7 @@
 	REG_USER_MR,
 	DEREG_MR,
 	ALLOC_MR,
+	MAP_MR_SG,
 	ALLOC_FMR,
 	MAP_PHYS_FMR,
 	UNMAP_FMR,
@@ -634,6 +635,12 @@
 				      rvt_alloc_mr);
 		break;
 
+	case MAP_MR_SG:
+		check_driver_override(rdi, offsetof(struct ib_device,
+						    map_mr_sg),
+				      rvt_map_mr_sg);
+		break;
+
 	case MAP_PHYS_FMR:
 		check_driver_override(rdi, offsetof(struct ib_device,
 						    map_phys_fmr),