Why is NVMe SSD drive failing registration?

[YogiWannabe]

Hi,

We have developed a NVME SSD PCIe drive that works on Linux and Windows. The card has a minimum block size of 4K. I tested the card on ESXI 6.7. The card shows up as vmhba2 but does not appear in the storage->devices list. I can see that ESXi creates all the queues and reads a block of data from our SSD drive. I can also use esxcli to querry the drive, read controller ID and log pages. All that works fine. In the vmkernel.log I see the following:

2018-12-05T12:35:56.616Z cpu23:2098770)VMWARE SCSI Id: Id for vmhba2:C0:T0:L0
0x31 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x2e 0x31 0x41 0x4c 0x32 0x30 0x31 0x36
2018-12-05T12:35:56.616Z cpu23:2098770)ScsiDeviceIO: 7998: QErr is correctly set to 0x0 for device t10.NVMe____AL2016............................AL20161..................100000001.
2018-12-05T12:35:56.616Z cpu28:2097231)ScsiDeviceIO: 3015: Cmd(0x45a240548b40) 0x1a, CmdSN 0x372 from world 0 to dev "t10.NVMe____AL2016............................AL20161..................100000001" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0x5
2018-12-05T12:35:56.616Z cpu28:2097231)0x24 0x0.
2018-12-05T12:35:56.616Z cpu23:2098770)ScsiDeviceIO: 8495: Could not detect setting of sitpua for device t10.NVMe____AL2016............................AL20161..................100000001. Error Not supported.
2018-12-05T12:35:56.616Z cpu23:2098770)ScsiDevice: 3636: Failing registration of device 't10.NVMe____AL2016............................AL20161..................100000001': Unsupported device attributes isLocal:1, isSSD:1, isNmpPlugin:1
2018-12-05T12:35:56.616Z cpu23:2098770)ScsiDevice: 5224: Failed to Unregister 'REPORTED LUNS DATA CHANGED' unit attention for device:t10.NVMe____AL2016............................AL20161..................100000001. Reason: Not found
2018-12-05T12:35:56.616Z cpu23:2098770)ScsiDevice: 5234: Failed to Unregister 'MODE PARAMETERS CHANGED' unit attention for device:t10.NVMe____AL2016............................AL20161..................100000001. Reason: Not found
2018-12-05T12:35:56.616Z cpu23:2098770)ScsiDevice: 5244: Failed to Unregister 'CAPACITY DATA HAS CHANGED' unit attention for device:t10.NVMe____AL2016............................AL20161..................100000001. Reason: Not found
2018-12-05T12:35:56.616Z cpu23:2098770)ScsiDevice: 5254: Failed to Unregister 'ASYMMETRIC ACCESS STATE CHANGED' unit attention for device:t10.NVMe____AL2016............................AL20161..................100000001. Reason: Not found
2018-12-05T12:35:56.616Z cpu23:2098770)ScsiDevice: 5264: Failed to Unregister 'INQUIRY PARAMETERS CHANGED' unit attention for device:t10.NVMe____AL2016............................AL20161..................100000001. Reason: Not found
2018-12-05T12:35:56.616Z cpu23:2098770)ScsiEvents: 545: Event Subsystem: Device Events, Destroyed!
2018-12-05T12:35:56.616Z cpu23:2098770)WARNING: NMP: nmp_RegisterDevice:851: Registration of NMP device with primary uid 't10.NVMe____AL2016............................AL20161..................100000001' failed. Not supported
2018-12-05T12:35:56.616Z cpu23:2098770)StorageApdHandler: 1063: Freeing APD handle 0x4303b5b6b160 []
2018-12-05T12:35:56.616Z cpu23:2098770)StorageApdHandler: 1147: APD Handle freed!

It's not clear why ESXi is failing the registration. Any points on how I can proceed with this issue? I'm new to ESXi

Thanks for your help