Re: [PATCH v4 06/14] hw/block/nvme: Add support for active/inactive namespaces

[Niklas Cassel]

On Thu, Sep 24, 2020 at 08:55:24PM +0200, Klaus Jensen wrote:
> On Sep 24 18:17, Niklas Cassel wrote:
> > On Thu, Sep 24, 2020 at 02:12:03PM +0200, Klaus Jensen wrote:
> > > On Sep 24 03:20, Dmitry Fomichev wrote:
> > > > From: Niklas Cassel <niklas.cassel@wdc.com>
> > > > 
> > > > E.g., if the user sets CC.CSS to Admin Only, NVM namespaces should be
> > > > marked as inactive.
> > > > 
> > > 
> > > Hmm. I'm not convinced that this is correct. Can you reference the spec?
> > > 
> > 
> > CC.CSS can only be changed when the controller is disabled.
> 
> Right. I think I see you point. While the controller is disabled, the
> host obviously cannot even see what namespaces are available, so the
> controller is free to only expose (aka, attach) the namespaces that
> makes sense for the value of CC.CSS.
> 
> OK then, the patch is good :)

That was my thought, that the controller internally would
detach unsupported namespaces (even if the controller didn't
expose namespace management capabilities to the user).

This was how I assumed that things worked, but if we should
follow the spec strictly, we should do like you suggested
and keep them attached, and return the proper error code,
on non-admin commands.

Thank you for improving my understanding.
Considering that CC.CSS can only be changed when the controller
is disabled, I still kind of wished that the spec said that
unsupported namespaces would be automatically detached.


Kind regards,
Niklas