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

[Ghalem Boudour <ghalem.boudour@6wind.com>]

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
>