isst_if_msr_cmds
cmd_cb.offset = offsetof(struct isst_if_msr_cmds, msr_cmd);
#define ISST_IF_MSR_COMMAND _IOWR(ISST_IF_MAGIC, 4, struct isst_if_msr_cmds *)
struct isst_if_msr_cmds msr_cmds;