Re: [PATCHv3 3/5] nvme: implement I/O Command Sets Command Set support

[Niklas Cassel <Niklas.Cassel@wdc.com>]

On Tue, Jun 23, 2020 at 08:20:23AM +0200, Hannes Reinecke wrote:
> On 6/22/20 6:25 PM, Keith Busch wrote:
> > From: Niklas Cassel <niklas.cassel@wdc.com>
> > 
> > Implements support for the I/O Command Sets command set. The command set
> > introduces a method to enumerate multiple command sets per namespace. If
> > the command set is exposed, this method for enumeration will be used
> > instead of the traditional method that uses the CC.CSS register command
> > set register for command set identification.
> > 
> > For namespaces where the Command Set Identifier is not supported or
> > recognized, the specific namespace will not be created.
> > 
> > Reviewed-by: Javier González <javier.gonz@samsung.com>
> > Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
> > Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> > Reviewed-by: Matias Bjørling <matias.bjorling@wdc.com>
> > Reviewed-by: Daniel Wagner <dwagner@suse.de>
> > Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
> > ---
> > @@ -1792,7 +1811,7 @@ static int nvme_report_ns_ids(struct nvme_ctrl *ctrl, unsigned int nsid,
> >   		memcpy(ids->eui64, id->eui64, sizeof(id->eui64));
> >   	if (ctrl->vs >= NVME_VS(1, 2, 0))
> >   		memcpy(ids->nguid, id->nguid, sizeof(id->nguid));
> > -	if (ctrl->vs >= NVME_VS(1, 3, 0))
> > +	if (ctrl->vs >= NVME_VS(1, 3, 0) || nvme_multi_css(ctrl))
> >   		return nvme_identify_ns_descs(ctrl, nsid, ids);
> >   	return 0;
> >   }
> 
> Hmm? Are command sets even defined for something earlier than 1.3?

According to Keith, usually new features are not really tied to a
specific NVMe version.

So if someone implements/enables multiple command sets feature on
an older base spec of NVMe, we still want to support/allow that.


Kind regards,
Niklas