NAME

       ibv_rereg_mr - re-register a memory region (MR)

SYNOPSIS

       #include <infiniband/verbs.h>

       int ibv_rereg_mr(struct ibv_mr *mr, int  flags,
                        struct ibv_pd * pd, void  *addr,
                        size_t  length, int  access);

DESCRIPTION

       ibv_rereg_mr()   Modifies   the   attributes   of  an  existing  memory  region  (MR)  mr.
       Conceptually, this call performs  the  functions  deregister  memory  region  followed  by
       register  memory  region.  Where possible, resources are reused instead of deallocated and
       reallocated.

       flags is a bit-mask used to indicate which of  the  following  properties  of  the  memory
       region are being modified. Flags should be a combination (bit field) of:

       IBV_REREG_MR_CHANGE_TRANSLATION  Change translation (location and length)

       IBV_REREG_MR_CHANGE_PD  Change protection domain

       IBV_REREG_MR_CHANGE_ACCESS  Change access flags

       When IBV_REREG_MR_CHANGE_PD is used, pd represents the new PD this MR should be registered
       to.
       When IBV_REREG_MR_CHANGE_TRANSLATION is used, addr.  represents the virtual address (user-
       space pointer) of the new MR, while length represents its length.

       The  access and other flags are represented in the field access.  This field describes the
       desired memory protection attributes; it is either 0 or the bitwise OR of one or  more  of
       ibv_access_flags.

       RETURN VALUE
              ibv_rereg_mr()  returns  0  on  success,  otherwise  an  error  has  occurred, enum
              ibv_rereg_mr_err_code represents the error as of below.
              IBV_REREG_MR_ERR_INPUT  -  Old  MR  is  valid,  an  input  error  was  detected  by
              libibverbs.
              IBV_REREG_MR_ERR_DONT_FORK_NEW  -  Old  MR  is  valid, failed via don't fork on new
              address range.
              IBV_REREG_MR_ERR_DO_FORK_OLD - New MR is valid, failed via do fork on  old  address
              range.
              IBV_REREG_MR_ERR_CMD - MR shouldn't be used, command error.
              IBV_REREG_MR_ERR_CMD_AND_DO_FORK_NEW - MR shouldn't be used, command error, invalid
              fork state on new address range.

NOTES

       Even on a failure, the user still needs to call ibv_dereg_mr on this MR.

SEE ALSO

       ibv_reg_mr(3), ibv_dereg_mr(3),

AUTHORS

       Matan Barak <matanb@mellanox.com>

       Yishai Hadas <yishaih@mellanox.com>