【Rdma-core and kernel compatibility issues】

[oulijun <oulijun@xxxxxxxxxx>]

Hi, Jason & leon
   I noticed that the 2 new changes in IB/core in 5.0 caused the rdma-core-v17 to be incompatible.
   The patch-set as follows:
	3c2c209 RDMA/uverbs: Use uverbs_request() for request copying
	29a29d1 RDMA/uverbs: Use uverbs_request() and core for write_ex handlers

   The 2 changes for resolve the following question?  for exmaple, the kernel define a struct:
   struct hns_roce_ib_create_qp {
        __aligned_u64 buf_addr;
        __aligned_u64 db_addr;
        __u8    log_sq_bb_count;
        __u8    log_sq_stride;
        __u8    sq_no_prefetch;
        __u8    reserved[5];
       // __aligned_u64 sdb_addr;
};

the size is 24 bytes

if the user define a struct:
 struct hns_roce_create_qp {
	struct ibv_create_qp		ibv_cmd;
	__u64				buf_addr;
	__u64				db_addr;
	__u8				log_sq_bb_count;
	__u8				log_sq_stride;
	__u8				sq_no_prefetch;
	__u8				reserved[5];
	__u64				sdb_addr;
};

the size is 32 bytes

thanks
Lijun Ou