RE: [PATCH] net/iavf: initialize large VF setting at startup

["Xu, Ting" <ting.xu@intel.com>]

> -----Original Message-----
> From: Ghalem Boudour <ghalem.boudour@6wind.com>
> Sent: Thursday, February 10, 2022 3:27 AM
> To: Xu, Ting <ting.xu@intel.com>
> Cc: Wu, Jingjing <jingjing.wu@intel.com>; Xing, Beilei <beilei.xing@intel.com>;
> dev@dpdk.org; Thibaut Collet <thibaut.collet@6wind.com>; Olivier Matz
> <olivier.matz@6wind.com>
> Subject: Re: [PATCH] net/iavf: initialize large VF setting at startup
> 
> Hi Ting,
> 
> The purpose of the correction is to ensure that the rss configuration is
> aligned with the number of queues allocated on the current boot and not
> impacted by a previous configuration done in a previous boot.
> The rss configuration is only available if VIRTCHNL_VF_OFFLOAD_RSS_PF is
> present and that is the reason that we have set the operation in part of
> VIRTCHNL_VF_OFFLOAD_RSS_PF.
> 
> Nevertheless this operation can be moved outside to be more generic and
> also covers iavf_config_irq_map.
> 
> On Wed, Feb 9, 2022 at 3:42 AM Xu, Ting <ting.xu@intel.com> wrote:
> >
> > > -----Original Message-----
> > > From: Ghalem Boudour <ghalem.boudour@6wind.com>
> > > Sent: Thursday, February 3, 2022 5:04 PM
> > > To: Wu, Jingjing <jingjing.wu@intel.com>; Xing, Beilei
> > > <beilei.xing@intel.com>
> > > Cc: dev@dpdk.org; Ghalem Boudour <ghalem.boudour@6wind.com>;
> Thibaut
> > > Collet <thibaut.collet@6wind.com>; Olivier Matz
> > > <olivier.matz@6wind.com>
> > > Subject: [PATCH] net/iavf: initialize large VF setting at startup
> > >
> > > lv_enabled is used to remember if large VF setting is configured,
> > > but its value is not initialized at startup. This can lead to a
> > > different configuration regarding the initial configuration of the PF.
> > > For example, a first start is done with 8 rx and 8 tx queues. Large
> > > VF is not needed and reta size is 64.
> > > A second start is done with 20 rx and tx queues. Large VF is
> > > required and reta size is 256.
> > > A third start is done with 2 rx and tx queues. Large VF is not
> > > needed but reta size is 256 as the PF has been configured during the
> second start.
> > >
> > > In order to have a consistent behavior regarding reta size whatever
> > > the configuration of the PF (may be changed by a previous boot) the
> > > lv_enabled must be set properly at the init phase.
> > >
> > > Signed-off-by: Ghalem Boudour <ghalem.boudour@6wind.com>
> > > Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com>
> > > Reviewed-by: Olivier Matz <olivier.matz@6wind.com>
> > > ---
> > >  drivers/net/iavf/iavf_ethdev.c | 2 ++
> > >  1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/net/iavf/iavf_ethdev.c
> > > b/drivers/net/iavf/iavf_ethdev.c index 79397f15e54f..09410be4b712
> > > 100644
> > > --- a/drivers/net/iavf/iavf_ethdev.c
> > > +++ b/drivers/net/iavf/iavf_ethdev.c
> > > @@ -2276,6 +2276,8 @@ iavf_init_vf(struct rte_eth_dev *dev)
> > >                       PMD_INIT_LOG(ERR, "unable to allocate rss_lut
> > > memory");
> > >                       goto err_rss;
> > >               }
> > > +             if (vf->vsi_res->num_queue_pairs >
> > > IAVF_MAX_NUM_QUEUES_DFLT)
> > > +                     vf->lv_enabled = true;
> >
> > Why you put this operation in the part of "
> VIRTCHNL_VF_OFFLOAD_RSS_PF"?
> >
> > >       }
> > >
> > >       if (vf->vf_res->vf_cap_flags &
> > > VIRTCHNL_VF_OFFLOAD_RX_FLEX_DESC) {
> > > --
> > > 2.30.2
> >

I think it is OK to move outside to the generic vf initialization since it is not only bound with RSS, what's your opinion?