[dpdk-dev] [PATCH v3 0/6] Enable VF RSS for Niantic

[Ouyang, Changchun]

> -----Original Message-----
> From: Richardson, Bruce
> Sent: Monday, January 5, 2015 6:38 PM
> To: Ouyang, Changchun
> Cc: Vlad Zolotarov; dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v3 0/6] Enable VF RSS for Niantic
> 
> On Thu, Dec 25, 2014 at 01:46:54AM +0000, Ouyang, Changchun wrote:
> > Hi,
> >
> > > -----Original Message-----
> > > From: Vlad Zolotarov [mailto:vladz at cloudius-systems.com]
> > > Sent: Wednesday, December 24, 2014 5:59 PM
> > > To: Ouyang, Changchun; dev at dpdk.org
> > > Subject: Re: [dpdk-dev] [PATCH v3 0/6] Enable VF RSS for Niantic
> > >
>  >
> > > On the contrary - it's a very good idea! We use DPDK on Amazon's
> > > guests with enhanced networking and we have no access to the PF. We
> > > still need to know the RSS redirection rules for our VF pool. From
> > > the 82599 spec, chapter
> > > 4.6.10.1.1: "redirection table is common to all the pools and only
> > > indicates the queue inside the pool to use once the pool is chosen".
> > > In that case we need to get the whole 128 entries of the RETA. Is
> > > there a reason why we can't have it?
> > >
> > Due to hardware limitation, VF could not query its own reta table,
> > because there is not its own reta, The reta table shared by pf and all vfs.
> > If you need know it, query them on pf is feasible way to do it.
> >
> It's not feasible if you only have access to a guest. :-) IMHO since the guest is
> seeing the results of the RSS redirection table, it should be able to query the
> table, if it wants. It should not, however, be able to modify the table, as it is
> owned by the PF.

Understand the situation, but the real issue is that the guest has no way to know the rss redirection table, so it could not query it.