So looking at this code, if a modem supports two SIMs, than OFONO_RIL_MULTI_SIM would be set to 1, and thus an additional create_rilmodem() call happens?

Wouldn't it make more sense to name this variable OFONO_RIL_NUM_SIMS, default 'num_slots' to 1, and then get rid of the create_rilmodem() call on line 97?