Thanks! So you have a LSI SAS3108? Yeah, I think that can do HBA mode, and that perfectly answers my question, as you can see at the bottom line, that is using the megaraid_sas driver and not the mpt3sas or other driver. That's exactly what I wanted to know. From my experience, if it is using the megaraid_sas driver, one issue you will have (compared to proper IT mode firmware) is that the /dev/sgX devices don't show up, so you can't run sg_format on the HDDs in the megaraid "HBA" mode. At least, I had that problem with Dell H330 with megaraid firmware and using the megaraid_sas driver. Once I moved to a proper IT mode firmware card, I could access the /dev/sgX devices.
Now, LSI SAS3108 probably means that machine is NOT the M3, right? I think the M3 generation of machines only had SAS2008 or SAS2208, no?