Re: [PATCH] doc: update TAP device features

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 4 Oct 2024 02:48:21 +0100
Ferruh Yigit <ferruh.yigit@amd.com> wrote:

> On 9/4/2024 4:42 PM, Stephen Hemminger wrote:
> > The TAP device does have per-queue stats and handles multi-process.
> > 
> > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> > ---
> >  doc/guides/nics/features/tap.ini | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/doc/guides/nics/features/tap.ini b/doc/guides/nics/features/tap.ini
> > index f26355e57f..f2ea5cd833 100644
> > --- a/doc/guides/nics/features/tap.ini
> > +++ b/doc/guides/nics/features/tap.ini
> > @@ -14,10 +14,12 @@ Basic stats          = Y
> >  L3 checksum offload  = Y
> >  L4 checksum offload  = Y
> >  MTU update           = Y
> > +Multiprocess aware   = Y
> >  
> 
> ack
> 
> >  Multicast MAC filter = Y
> >  Unicast MAC filter   = Y
> >  Packet type parsing  = Y
> >  Flow control         = Y
> > +Stats per queue      = Y
> >  
> 
> This feature name is misleading,
> it is for 'rte_eth_dev_set_[rt]x_queue_stats_mapping()' API, which is
> indeed for covering limitation for some drivers.
> Tap does support getting stats per queue, but doesn't support above
> documented feature.

The stats queue mapping was a feature that was hinted at being removed.
It only exists because of HW limitations on Intel ixgbe NIC and SW
limitations from RTE_ETHDEV_QUEUE_STAT_CNTRS.

Perhaps there should be a generic SW emulation for this the mapping?