Re: [dpdk-dev] [PATCH] net/iavf: fix adding multicast MAC address

["Sun, GuinanX" <guinanx.sun@intel.com>]

Hi beilei

> -----Original Message-----
> From: Xing, Beilei <beilei.xing@intel.com>
> Sent: Thursday, October 15, 2020 1:37 PM
> To: Peng, Yuan <yuan.peng@intel.com>; Sun, GuinanX
> <guinanx.sun@intel.com>; dev@dpdk.org
> Cc: Wu, Jingjing <jingjing.wu@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>;
> Sun, GuinanX <guinanx.sun@intel.com>
> Subject: RE: [dpdk-dev] [PATCH] net/iavf: fix adding multicast MAC address
> 
> 
> 
> > -----Original Message-----
> > From: Peng, Yuan <yuan.peng@intel.com>
> > Sent: Thursday, October 15, 2020 1:14 PM
> > To: Sun, GuinanX <guinanx.sun@intel.com>; dev@dpdk.org
> > Cc: Xing, Beilei <beilei.xing@intel.com>; Wu, Jingjing
> > <jingjing.wu@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>; Sun,
> > GuinanX <guinanx.sun@intel.com>
> > Subject: RE: [dpdk-dev] [PATCH] net/iavf: fix adding multicast MAC
> > address
> >
> > Test-by Peng, Yuan <yuan.peng@intel.com>
> >
> >
> > -----Original Message-----
> > From: dev <dev-bounces@dpdk.org> On Behalf Of Guinan Sun
> > Sent: Thursday, October 15, 2020 10:02 AM
> > To: dev@dpdk.org
> > Cc: Xing, Beilei <beilei.xing@intel.com>; Wu, Jingjing
> > <jingjing.wu@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>; Sun,
> > GuinanX <guinanx.sun@intel.com>
> > Subject: [dpdk-dev] [PATCH] net/iavf: fix adding multicast MAC address
> >
> > When the multicast address is added, it will flush previous addresses
> > first, and then add new ones.
> > So when adding an address that exceeds the upper limit causes a
> > failure, you need to add the previous address list back. This patch fixes the
> issue.
> >
> > Fixes: 05e4c3aff35f ("net/iavf: support multicast configuration")
> >
> > Signed-off-by: Guinan Sun <guinanx.sun@intel.com>
> > ---
> >  drivers/net/iavf/iavf_ethdev.c | 30 ++++++++++++++++++++++--------
> > drivers/net/iavf/iavf_vchnl.c  |  3 ---
> >  2 files changed, 22 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/net/iavf/iavf_ethdev.c
> > b/drivers/net/iavf/iavf_ethdev.c index e68e3bc71..042edadd9 100644
> > --- a/drivers/net/iavf/iavf_ethdev.c
> > +++ b/drivers/net/iavf/iavf_ethdev.c
> > @@ -164,7 +164,14 @@ iavf_set_mc_addr_list(struct rte_eth_dev *dev,
> > struct iavf_info *vf = IAVF_DEV_PRIVATE_TO_VF(dev->data-
> > >dev_private);
> >  struct iavf_adapter *adapter =
> >  IAVF_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
> > -int err;
> > +int err, temp_err;
> > +
> > +if (mc_addrs_num > IAVF_NUM_MACADDR_MAX) { PMD_DRV_LOG(ERR,
> > +    "can't add more than a limited number (%u) of
> > addresses.",
> > +    (uint32_t)IAVF_NUM_MACADDR_MAX);
> > +return -EINVAL;
> > +}
> >
> >  /* flush previous addresses */
> >  err = iavf_add_del_mc_addr_list(adapter, vf->mc_addrs, vf-
> > >mc_addrs_num, @@ -172,17 +179,24 @@ iavf_set_mc_addr_list(struct
> > rte_eth_dev *dev,
> >  if (err)
> >  return err;
> >
> > -vf->mc_addrs_num = 0;
> > -
> >  /* add new ones */
> >  err = iavf_add_del_mc_addr_list(adapter, mc_addrs, mc_addrs_num,
> > true); -if (err) -return err;
> >
> > -vf->mc_addrs_num = mc_addrs_num;
> > -memcpy(vf->mc_addrs, mc_addrs, mc_addrs_num * sizeof(*mc_addrs));
> > +if (err) {
> > +/* When adding new addresses fail, need to add the
> > + * previous addresses back.
> > + */
> > +temp_err = iavf_add_del_mc_addr_list(adapter, vf->mc_addrs,
> > +     vf->mc_addrs_num, true);
> 
> Can we reuse err here?

This err cannot be reused.

When performing mac address addition, the testpmd side will first add the mac address to mac_pool.
When the driver layer returns that it failed to add an address, the tespmd layer will delete the failed address from mac_pool.

If err is reused, the successful result of executing the add back address will overwrite the previous err, causing problems with the address stored in mac_pool on the testpmd side.

> 
> > +if (temp_err)
> > +return temp_err;
> > +} else {
> > +vf->mc_addrs_num = mc_addrs_num;
> > +memcpy(vf->mc_addrs,
> > +       mc_addrs, mc_addrs_num * sizeof(*mc_addrs)); }
> >
> > -return 0;
> > +return err;
> >  }
> >
> >  static int
> > diff --git a/drivers/net/iavf/iavf_vchnl.c
> > b/drivers/net/iavf/iavf_vchnl.c index
> > db0b76876..a2295f879 100644
> > --- a/drivers/net/iavf/iavf_vchnl.c
> > +++ b/drivers/net/iavf/iavf_vchnl.c
> > @@ -1107,9 +1107,6 @@ iavf_add_del_mc_addr_list(struct iavf_adapter
> > *adapter,  if (mc_addrs == NULL || mc_addrs_num == 0)  return 0;
> >
> > -if (mc_addrs_num > IAVF_NUM_MACADDR_MAX) -return -EINVAL;
> > -
> >  list = (struct virtchnl_ether_addr_list *)cmd_buffer;  list->vsi_id =
> > vf->vsi_res->vsi_id;  list->num_elements = mc_addrs_num;
> > --
> > 2.13.6
>