Re: [PATCH 3/9] hw/block/nvme: support per-namespace smart log

[Keith Busch]

On Thu, Oct 01, 2020 at 06:10:57AM +0200, Klaus Jensen wrote:
> On Sep 30 15:04, Keith Busch wrote:
> > Let the user specify a specific namespace if they want to get access
> > stats for a specific namespace.
> > 
> 
> I don't think this makes sense for v1.3+.
> 
> NVM Express v1.3d, Section 5.14.1.2: "There is no namespace specific
> information defined in the SMART / Health log page in this revision of
> the specification.  therefore the controller log page and namespace
> specific log page contain identical information".
> 
> I have no idea why the TWG decided this, but that's the way it is ;)

I don't think they did that. The behavior you're referring to is specific to
controllers that operate a particular way: "If the log page is not supported on
a per namespace basis ...". They were trying to provide a spec compliant way
for controllers to return a success status if you supplied a valid NSID when
the controller doesn't support per-namespace smart data..

The previous paragraph is more clear on this: "The controller may also support
requesting the log page on a per namespace basis, as indicated by bit 0 of the
LPA field in the Identify Controller data structure".