Re: [PATCH] net/ixgbevf: fix promiscuous and allmulti

[Olivier Matz <olivier.matz@6wind.com>]

Hi Wenjun,

On Mon, Oct 10, 2022 at 01:30:54AM +0000, Wu, Wenjun1 wrote:
> Hi Olivier,
> 
> > -----Original Message-----
> > From: Olivier Matz <olivier.matz@6wind.com>
> > Sent: Thursday, September 29, 2022 8:22 PM
> > To: dev@dpdk.org
> > Cc: Yang, Qiming <qiming.yang@intel.com>; Wu, Wenjun1
> > <wenjun1.wu@intel.com>; Zhao1, Wei <wei.zhao1@intel.com>
> > Subject: [PATCH] net/ixgbevf: fix promiscuous and allmulti
> > 
> > The configuration of allmulti and promiscuous modes conflicts together. For
> > instance, if we enable promiscuous mode, then enable and disable allmulti,
> > then the promiscuous mode is wrongly disabled.
> > 
> > Fix this behavior by:
> > - doing nothing when we set/unset allmulti if promiscuous mode is on
> > - restorting the proper mode (none or allmulti) when we disable
> >   promiscuous mode
> > 
> > Fixes: 1f4564ed7696 ("net/ixgbevf: enable promiscuous mode")
> > 
> > Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
> > ---
> > 
> > Hi,
> > 
> > For reference, this was tested with this plan:
> > 
> > echo 8 > "/sys/bus/pci/devices/0000:01:00.1/sriov_numvfs"
> > ip link set dev eno2 up
> > ip link set dev eno2 promisc on
> > bridge link set dev eno2 hwmode veb
> > ip link set dev eno2 mtu 9000
> > 
> > ip link set dev eno2 vf 0 mac ac:1f:6b:fe:ba:b0 ip link set dev eno2 vf 0
> > spoofchk off ip link set dev eno2 vf 0 trust on
> > 
> > ip link set dev eno2 vf 1 mac ac:1f:6b:fe:ba:b1 ip link set dev eno2 vf 1
> > spoofchk off ip link set dev eno2 vf 1 trust on
> > 
> > python3 usertools/dpdk-devbind.py -s
> > python3 usertools/dpdk-devbind.py -b vfio-pci 0000:01:10.1   # vf 0
> > python3 usertools/dpdk-devbind.py -b ixgbevf 0000:01:10.3    # vf 1
> > 
> > 
> > # in another terminal
> > scapy
> > while True:
> >   sendp(Ether(dst='ac:1f:6b:00:00:00'), iface='eno2v1')  # wrong mac
> >   sendp(Ether(dst='ac:1f:6b:fe:ba:b0'), iface='eno2v1')  # correct mac
> >   time.sleep(1)
> > 
> > 
> > ./build/app/dpdk-testpmd -l 1,2 -a 0000:01:10.1 -- -i --total-num-
> > mbufs=32768 show port info all set fwd rxonly set verbose 1 set promisc all
> > off set allmulti all off start
> > 
> > # ok, only packets to dst='ac:1f:6b:fe:ba:b0' are received
> > 
> > 
> > # ok, both packets are received
> > set promisc all on
> > 
> > 
> > # nok, only packets to dst='ac:1f:6b:fe:ba:b0' are received set allmulti all on
> > set allmulti all off
> > 
> > 
> >  drivers/net/ixgbe/ixgbe_ethdev.c | 12 +++++++++++-
> >  1 file changed, 11 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
> > b/drivers/net/ixgbe/ixgbe_ethdev.c
> > index 8cec951d94..cc8383c5a9 100644
> > --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> > +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> > @@ -7785,9 +7785,13 @@ static int
> >  ixgbevf_dev_promiscuous_disable(struct rte_eth_dev *dev)  {
> >  	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data-
> > >dev_private);
> > +	int mode = IXGBEVF_XCAST_MODE_NONE;
> >  	int ret;
> > 
> > -	switch (hw->mac.ops.update_xcast_mode(hw,
> > IXGBEVF_XCAST_MODE_NONE)) {
> > +	if (dev->data->all_multicast)
> > +		mode = IXGBEVF_XCAST_MODE_ALLMULTI;
> > +
> > +	switch (hw->mac.ops.update_xcast_mode(hw, mode)) {
> >  	case IXGBE_SUCCESS:
> >  		ret = 0;
> >  		break;
> > @@ -7809,6 +7813,9 @@ ixgbevf_dev_allmulticast_enable(struct
> > rte_eth_dev *dev)
> >  	int ret;
> >  	int mode = IXGBEVF_XCAST_MODE_ALLMULTI;
> > 
> > +	if (dev->data->promiscuous)
> > +		return 0;
> > +
> >  	switch (hw->mac.ops.update_xcast_mode(hw, mode)) {
> >  	case IXGBE_SUCCESS:
> >  		ret = 0;
> > @@ -7830,6 +7837,9 @@ ixgbevf_dev_allmulticast_disable(struct
> > rte_eth_dev *dev)
> >  	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data-
> > >dev_private);
> >  	int ret;
> > 
> > +	if (dev->data->promiscuous)
> > +		return 0;
> > +
> 
> It seems that we cannot actually turn off allmulticast mode when promiscuous
> mode is enabled, so can we return error and add a log message here as a
> reminder?

I think we should not return an error here: when we disable all_multi, there are
2 cases:

1/ promiscuous is off: no issue here, we do as before, we ask the PF to disable
   the all_multi mode

2/ promiscuous is on: we have nothing to ask to the PF, because we still want
   to stay in promisc mode. We just need to remember that all_multi is disabled,
   and this is done already done by the ethdev layer.

On the PF dpdk driver, the behavior is the same: we can enable or disable
promisc and all_multi independently, and changing the all_multi value when
promisc is enabled is allowed and does not impact the rx traffic.


Thanks,
Olivier

> Thanks,
> Wenjun
> 
> >  	switch (hw->mac.ops.update_xcast_mode(hw,
> > IXGBEVF_XCAST_MODE_MULTI)) {
> >  	case IXGBE_SUCCESS:
> >  		ret = 0;
> > --
> > 2.30.2
>