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Change pscsi to look at the underlying device limits? Yes. I think there might be 2 things to do here: 1. SCSI VPD values. I think we would do something similar to iblock_configure_device where when we setup the device we look at the underlying device's limits and then set the se_device's limits. Those values then get reported to the initiator in the VPD info, so that would be useful for normal drivers like iscsi and FC. For the max segments there's not a SCSI VPD value, but we have this code: /* * Set MAXIMUM TRANSFER LENGTH * * XXX: Currently assumes single PAGE_SIZE per scatterlist for fabrics * enforcing maximum HW scatter-gather-list entry limit */ if (cmd->se_tfo->max_data_sg_nents) { mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE) / dev->dev_attrib.block_size; } put_unaligned_be32(min_not_zero(mtl, dev->dev_attrib.hw_max_sectors), &buf[8]); which would limit the IO size. max_data_sg_nents is only currently a fabric driver (front end drivers like iscsi, fc, etc) limit, so we would need to make that more generic so backends like pscsi can set it. 2. For loop we have the sg_tablesize setting like you saw, but the problem is that it's host level and we don't know the devices when we add the host. I think we would have to modify tcm_loop_port_link so if adds the device successfully, we call blk_queue_max_segments. Christoph is that what you were thinking?