[PATCH] nvme: add DIX support for nvme-rdma

[Max Gurtovoy]

On 9/6/2022 9:59 AM, Christoph Hellwig wrote:
> On Tue, Sep 06, 2022 at 10:13:42AM +0800, Chao Leng wrote:
>> Although the NVMe protocol does not define in detail how DIX should
>> be supported.
> NVMe describes how protection information works very well.  It does not
> use "DIX" at all to reference those features.  And remember that even
> for SCSI DIX is not a normative on the wire protocol, but just an
> interface for HBAs on how to allow the host to interact with the actual
> wire protocol.

Maybe we can extend the spec and say that for Fabrics only we can use 
IP_CSUM as protection for "host_buf-------->host HBA".

On the wire we'll use extended LBA with CRC as defined today.

>
>> But The NVMe base spec says:
>> Additionally, support has been added for many Enterprise capabilities like
>> end-to-end data protection (compatible with SCSI Protection Information,
>> commonly known as T10 DIF, and SNIA DIX standards), enhanced error reporting,
>> and virtualization.
> None of which is normative language.