Re: [patch net-next 0/3] net: devlink: Finish network namespace support

[Jakub Kicinski <jakub.kicinski@netronome.com>]

On Wed, 31 Jul 2019 16:07:31 -0600, David Ahern wrote:
> On 7/31/19 4:02 PM, Jakub Kicinski wrote:
> > Can you elaborate further? Ports for most purposes are represented by
> > netdevices. Devlink port instances expose global topological view of
> > the ports which is primarily relevant if you can see the entire ASIC.
> > I think the global configuration and global view of resources is still
> > the most relevant need, so in your diagram you must account for some
> > "all-seeing" instance, e.g.:
> > 
> >    namespace 1 |  namespace 2  | ... | namespace N
> >                |               |     |
> >   { ports 1 }  |   { ports 2 } | ... | { ports N }
> >                |               |     |
> > subdevlink 1   | subdevlink 2  | ... |  subdevlink N
> >          \______      |              _______/
> >                  master ASIC devlink
> >   =================================================
> >                    driver
> > 
> > No?
> 
> sure, there could be a master devlink visible to the user if that makes
> sense or the driver can account for it behind the scenes as the sum of
> the devlink instances.
> 
> The goal is to allow ports within an asic [1] to be divided across
> network namespace where each namespace sees a subset of the ports. This
> allows creating multiple logical switches from a single physical asic.
> 
> [1] within constraints imposed by the driver/hardware - for example to
> account for resources shared by a set of ports. e.g., front panel ports
> 1 - 4 have shared resources and must always be in the same devlink instance.

So the ASIC would start out all partitioned? Presumably some would
still like to use it non-partitioned? What follows there must be a top
level instance to decide on partitioning, and moving resources between
sub-instances.

Right now I don't think there is much info in devlink ports which would
be relevant without full view of the ASIC..