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Re: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces functional after rxvlan off

Started byAlexander Duyck <alexander.duyck@gmail.com>
First post2016-06-01 16:40 +0200
Last post2016-06-10 01:30 +0200
Articles 7 — 2 participants

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  Re: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces  functional after rxvlan off Alexander Duyck <alexander.duyck@gmail.com> - 2016-06-01 16:40 +0200
    Re: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces  functional after rxvlan off Jarod Wilson <jarod@redhat.com> - 2016-06-01 21:30 +0200
      Re: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces  functional after rxvlan off Alexander Duyck <alexander.duyck@gmail.com> - 2016-06-02 00:40 +0200
        Re: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces  functional after rxvlan off Jarod Wilson <jarod@redhat.com> - 2016-06-09 20:10 +0200
          Re: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces  functional after rxvlan off Jarod Wilson <jarod@redhat.com> - 2016-06-09 23:00 +0200
            Re: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces  functional after rxvlan off Jarod Wilson <jarod@redhat.com> - 2016-06-10 00:20 +0200
              Re: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces  functional after rxvlan off Jarod Wilson <jarod@redhat.com> - 2016-06-10 01:30 +0200

#1411278 — Re: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces functional after rxvlan off

FromAlexander Duyck <alexander.duyck@gmail.com>
Date2016-06-01 16:40 +0200
SubjectRe: [Intel-wired-lan] [RFC PATCH net] e1000e: keep vlan interfaces functional after rxvlan off
Message-ID<rFfto-17P-11@gated-at.bofh.it>
On Tue, May 17, 2016 at 12:03 PM, Jarod Wilson <jarod@redhat.com> wrote:
> I've got a bug report about an e1000e interface, where a vlan interface is
> set up on top of it:
>
> $ ip link add link ens1f0 name ens1f0.99 type vlan id 99
> $ ip link set ens1f0 up
> $ ip link set ens1f0.99 up
> $ ip addr add 192.168.99.92 dev ens1f0.99
>
> At this point, I can ping another host on vlan 99, ip 192.168.99.91.
> However, if I do the following:
>
> $ ethtool -K ens1f0 rxvlan off
>
> Then no traffic passes on ens1f0.99. It comes back if I toggle rxvlan on
> again. I'm not sure if this is actually intended behavior, or if there's a
> lack of software vlan stripping fallback, or what, but things continue to
> work if I simply don't call e1000e_vlan_strip_disable() if there are
> active vlans (plagiarizing a function from the e1000 driver here) on the
> interface.
>
> Also slipped a related-ish fix to the kerneldoc text for
> e1000e_vlan_strip_disable here...
>
> CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> CC: intel-wired-lan@lists.osuosl.org
> CC: netdev@vger.kernel.org
> Signed-off-by: Jarod Wilson <jarod@redhat.com>
> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index 75e6089..73f7452 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -154,6 +154,16 @@ void __ew32(struct e1000_hw *hw, unsigned long reg, u32 val)
>         writel(val, hw->hw_addr + reg);
>  }
>
> +static bool e1000e_vlan_used(struct e1000_adapter *adapter)
> +{
> +       u16 vid;
> +
> +       for_each_set_bit(vid, adapter->active_vlans, VLAN_N_VID)
> +               return true;
> +

I'm pretty sure this is always going to return true if 8021q is loaded
because VLAN 0 is always added to the device even if no other VLANs
are in use.

> +       return false;
> +}
> +
>  /**
>   * e1000_regdump - register printout routine
>   * @hw: pointer to the HW structure
> @@ -2789,7 +2799,7 @@ static void e1000e_vlan_filter_enable(struct e1000_adapter *adapter)
>  }
>
>  /**
> - * e1000e_vlan_strip_enable - helper to disable HW VLAN stripping
> + * e1000e_vlan_strip_disable - helper to disable HW VLAN stripping
>   * @adapter: board private structure to initialize
>   **/
>  static void e1000e_vlan_strip_disable(struct e1000_adapter *adapter)
> @@ -3443,7 +3453,8 @@ static void e1000e_set_rx_mode(struct net_device *netdev)
>
>         ew32(RCTL, rctl);
>
> -       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
> +       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX ||
> +           e1000e_vlan_used(adapter))
>                 e1000e_vlan_strip_enable(adapter);
>         else
>                 e1000e_vlan_strip_disable(adapter);

So if the VLAN tag stripping is disabled what happens that is causing
the VLAN test to fail?  It sounds like this might be working around a
kernel bug where a VLAN created on a device that supports hardware tag
stripping only supports hardware tag stripping.  Maybe a better fix
would be to add a fall back so if the VLAN tag is in the frame instead
of stripped it still makes it to the correct spot.

- Alex

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#1411489

FromJarod Wilson <jarod@redhat.com>
Date2016-06-01 21:30 +0200
Message-ID<rFk02-488-13@gated-at.bofh.it>
In reply to#1411278
On Wed, Jun 01, 2016 at 07:31:53AM -0700, Alexander Duyck wrote:
> On Tue, May 17, 2016 at 12:03 PM, Jarod Wilson <jarod@redhat.com> wrote:
> > I've got a bug report about an e1000e interface, where a vlan interface is
> > set up on top of it:
> >
> > $ ip link add link ens1f0 name ens1f0.99 type vlan id 99
> > $ ip link set ens1f0 up
> > $ ip link set ens1f0.99 up
> > $ ip addr add 192.168.99.92 dev ens1f0.99
> >
> > At this point, I can ping another host on vlan 99, ip 192.168.99.91.
> > However, if I do the following:
> >
> > $ ethtool -K ens1f0 rxvlan off
> >
> > Then no traffic passes on ens1f0.99. It comes back if I toggle rxvlan on
> > again. I'm not sure if this is actually intended behavior, or if there's a
> > lack of software vlan stripping fallback, or what, but things continue to
> > work if I simply don't call e1000e_vlan_strip_disable() if there are
> > active vlans (plagiarizing a function from the e1000 driver here) on the
> > interface.
> >
> > Also slipped a related-ish fix to the kerneldoc text for
> > e1000e_vlan_strip_disable here...
> >
> > CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> > CC: intel-wired-lan@lists.osuosl.org
> > CC: netdev@vger.kernel.org
> > Signed-off-by: Jarod Wilson <jarod@redhat.com>
> > ---
> >  drivers/net/ethernet/intel/e1000e/netdev.c | 15 +++++++++++++--
> >  1 file changed, 13 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > index 75e6089..73f7452 100644
> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > @@ -154,6 +154,16 @@ void __ew32(struct e1000_hw *hw, unsigned long reg, u32 val)
> >         writel(val, hw->hw_addr + reg);
> >  }
> >
> > +static bool e1000e_vlan_used(struct e1000_adapter *adapter)
> > +{
> > +       u16 vid;
> > +
> > +       for_each_set_bit(vid, adapter->active_vlans, VLAN_N_VID)
> > +               return true;
> > +
> 
> I'm pretty sure this is always going to return true if 8021q is loaded
> because VLAN 0 is always added to the device even if no other VLANs
> are in use.

Ah, hadn't considered that, I just plucked it straight from e1000.

> > +       return false;
> > +}
> > +
> >  /**
> >   * e1000_regdump - register printout routine
> >   * @hw: pointer to the HW structure
> > @@ -2789,7 +2799,7 @@ static void e1000e_vlan_filter_enable(struct e1000_adapter *adapter)
> >  }
> >
> >  /**
> > - * e1000e_vlan_strip_enable - helper to disable HW VLAN stripping
> > + * e1000e_vlan_strip_disable - helper to disable HW VLAN stripping
> >   * @adapter: board private structure to initialize
> >   **/
> >  static void e1000e_vlan_strip_disable(struct e1000_adapter *adapter)
> > @@ -3443,7 +3453,8 @@ static void e1000e_set_rx_mode(struct net_device *netdev)
> >
> >         ew32(RCTL, rctl);
> >
> > -       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
> > +       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX ||
> > +           e1000e_vlan_used(adapter))
> >                 e1000e_vlan_strip_enable(adapter);
> >         else
> >                 e1000e_vlan_strip_disable(adapter);
> 
> So if the VLAN tag stripping is disabled what happens that is causing
> the VLAN test to fail?  It sounds like this might be working around a
> kernel bug where a VLAN created on a device that supports hardware tag
> stripping only supports hardware tag stripping.  Maybe a better fix
> would be to add a fall back so if the VLAN tag is in the frame instead
> of stripped it still makes it to the correct spot.

That's the main reason I labeled it as an RFC -- I wasn't sure exactly how
things were intended to work when the hardware stripping was disabled. It
seems quite plausible to me that this patch simply papers over the real
bug: lack of a functional software fallback. I'm not particularly up on
the vlan code just yet though, so I'm not yet sure where to poke next.
Suggestions welcomed. :)

-- 
Jarod Wilson
jarod@redhat.com

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#1411630

FromAlexander Duyck <alexander.duyck@gmail.com>
Date2016-06-02 00:40 +0200
Message-ID<rFmXU-6a2-1@gated-at.bofh.it>
In reply to#1411489
On Wed, Jun 1, 2016 at 12:27 PM, Jarod Wilson <jarod@redhat.com> wrote:
> On Wed, Jun 01, 2016 at 07:31:53AM -0700, Alexander Duyck wrote:
>> On Tue, May 17, 2016 at 12:03 PM, Jarod Wilson <jarod@redhat.com> wrote:
>> > I've got a bug report about an e1000e interface, where a vlan interface is
>> > set up on top of it:
>> >
>> > $ ip link add link ens1f0 name ens1f0.99 type vlan id 99
>> > $ ip link set ens1f0 up
>> > $ ip link set ens1f0.99 up
>> > $ ip addr add 192.168.99.92 dev ens1f0.99
>> >
>> > At this point, I can ping another host on vlan 99, ip 192.168.99.91.
>> > However, if I do the following:
>> >
>> > $ ethtool -K ens1f0 rxvlan off
>> >
>> > Then no traffic passes on ens1f0.99. It comes back if I toggle rxvlan on
>> > again. I'm not sure if this is actually intended behavior, or if there's a
>> > lack of software vlan stripping fallback, or what, but things continue to
>> > work if I simply don't call e1000e_vlan_strip_disable() if there are
>> > active vlans (plagiarizing a function from the e1000 driver here) on the
>> > interface.
>> >
>> > Also slipped a related-ish fix to the kerneldoc text for
>> > e1000e_vlan_strip_disable here...
>> >
>> > CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
>> > CC: intel-wired-lan@lists.osuosl.org
>> > CC: netdev@vger.kernel.org
>> > Signed-off-by: Jarod Wilson <jarod@redhat.com>
>> > ---
>> >  drivers/net/ethernet/intel/e1000e/netdev.c | 15 +++++++++++++--
>> >  1 file changed, 13 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
>> > index 75e6089..73f7452 100644
>> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
>> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
>> > @@ -154,6 +154,16 @@ void __ew32(struct e1000_hw *hw, unsigned long reg, u32 val)
>> >         writel(val, hw->hw_addr + reg);
>> >  }
>> >
>> > +static bool e1000e_vlan_used(struct e1000_adapter *adapter)
>> > +{
>> > +       u16 vid;
>> > +
>> > +       for_each_set_bit(vid, adapter->active_vlans, VLAN_N_VID)
>> > +               return true;
>> > +
>>
>> I'm pretty sure this is always going to return true if 8021q is loaded
>> because VLAN 0 is always added to the device even if no other VLANs
>> are in use.
>
> Ah, hadn't considered that, I just plucked it straight from e1000.
>
>> > +       return false;
>> > +}
>> > +
>> >  /**
>> >   * e1000_regdump - register printout routine
>> >   * @hw: pointer to the HW structure
>> > @@ -2789,7 +2799,7 @@ static void e1000e_vlan_filter_enable(struct e1000_adapter *adapter)
>> >  }
>> >
>> >  /**
>> > - * e1000e_vlan_strip_enable - helper to disable HW VLAN stripping
>> > + * e1000e_vlan_strip_disable - helper to disable HW VLAN stripping
>> >   * @adapter: board private structure to initialize
>> >   **/
>> >  static void e1000e_vlan_strip_disable(struct e1000_adapter *adapter)
>> > @@ -3443,7 +3453,8 @@ static void e1000e_set_rx_mode(struct net_device *netdev)
>> >
>> >         ew32(RCTL, rctl);
>> >
>> > -       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
>> > +       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX ||
>> > +           e1000e_vlan_used(adapter))
>> >                 e1000e_vlan_strip_enable(adapter);
>> >         else
>> >                 e1000e_vlan_strip_disable(adapter);
>>
>> So if the VLAN tag stripping is disabled what happens that is causing
>> the VLAN test to fail?  It sounds like this might be working around a
>> kernel bug where a VLAN created on a device that supports hardware tag
>> stripping only supports hardware tag stripping.  Maybe a better fix
>> would be to add a fall back so if the VLAN tag is in the frame instead
>> of stripped it still makes it to the correct spot.
>
> That's the main reason I labeled it as an RFC -- I wasn't sure exactly how
> things were intended to work when the hardware stripping was disabled. It
> seems quite plausible to me that this patch simply papers over the real
> bug: lack of a functional software fallback. I'm not particularly up on
> the vlan code just yet though, so I'm not yet sure where to poke next.
> Suggestions welcomed. :)

Well the software fallback should be the call to skb_vlan_untag in
__netif_receive_skb_core.  If that isn't being triggered then we
should probably be fixing the files in the core code then.

- Alex

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#1418546

FromJarod Wilson <jarod@redhat.com>
Date2016-06-09 20:10 +0200
Message-ID<rIcyZ-1vR-15@gated-at.bofh.it>
In reply to#1411630
On Wed, Jun 01, 2016 at 03:31:46PM -0700, Alexander Duyck wrote:
> On Wed, Jun 1, 2016 at 12:27 PM, Jarod Wilson <jarod@redhat.com> wrote:
> > On Wed, Jun 01, 2016 at 07:31:53AM -0700, Alexander Duyck wrote:
> >> On Tue, May 17, 2016 at 12:03 PM, Jarod Wilson <jarod@redhat.com> wrote:
> >> > I've got a bug report about an e1000e interface, where a vlan interface is
> >> > set up on top of it:
> >> >
> >> > $ ip link add link ens1f0 name ens1f0.99 type vlan id 99
> >> > $ ip link set ens1f0 up
> >> > $ ip link set ens1f0.99 up
> >> > $ ip addr add 192.168.99.92 dev ens1f0.99
> >> >
> >> > At this point, I can ping another host on vlan 99, ip 192.168.99.91.
> >> > However, if I do the following:
> >> >
> >> > $ ethtool -K ens1f0 rxvlan off
> >> >
> >> > Then no traffic passes on ens1f0.99. It comes back if I toggle rxvlan on
> >> > again. I'm not sure if this is actually intended behavior, or if there's a
> >> > lack of software vlan stripping fallback, or what, but things continue to
> >> > work if I simply don't call e1000e_vlan_strip_disable() if there are
> >> > active vlans (plagiarizing a function from the e1000 driver here) on the
> >> > interface.
> >> >
> >> > Also slipped a related-ish fix to the kerneldoc text for
> >> > e1000e_vlan_strip_disable here...
> >> >
> >> > CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> >> > CC: intel-wired-lan@lists.osuosl.org
> >> > CC: netdev@vger.kernel.org
> >> > Signed-off-by: Jarod Wilson <jarod@redhat.com>
> >> > ---
> >> >  drivers/net/ethernet/intel/e1000e/netdev.c | 15 +++++++++++++--
> >> >  1 file changed, 13 insertions(+), 2 deletions(-)
> >> >
> >> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> >> > index 75e6089..73f7452 100644
> >> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> >> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> >> > @@ -154,6 +154,16 @@ void __ew32(struct e1000_hw *hw, unsigned long reg, u32 val)
> >> >         writel(val, hw->hw_addr + reg);
> >> >  }
> >> >
> >> > +static bool e1000e_vlan_used(struct e1000_adapter *adapter)
> >> > +{
> >> > +       u16 vid;
> >> > +
> >> > +       for_each_set_bit(vid, adapter->active_vlans, VLAN_N_VID)
> >> > +               return true;
> >> > +
> >>
> >> I'm pretty sure this is always going to return true if 8021q is loaded
> >> because VLAN 0 is always added to the device even if no other VLANs
> >> are in use.
> >
> > Ah, hadn't considered that, I just plucked it straight from e1000.
> >
> >> > +       return false;
> >> > +}
> >> > +
> >> >  /**
> >> >   * e1000_regdump - register printout routine
> >> >   * @hw: pointer to the HW structure
> >> > @@ -2789,7 +2799,7 @@ static void e1000e_vlan_filter_enable(struct e1000_adapter *adapter)
> >> >  }
> >> >
> >> >  /**
> >> > - * e1000e_vlan_strip_enable - helper to disable HW VLAN stripping
> >> > + * e1000e_vlan_strip_disable - helper to disable HW VLAN stripping
> >> >   * @adapter: board private structure to initialize
> >> >   **/
> >> >  static void e1000e_vlan_strip_disable(struct e1000_adapter *adapter)
> >> > @@ -3443,7 +3453,8 @@ static void e1000e_set_rx_mode(struct net_device *netdev)
> >> >
> >> >         ew32(RCTL, rctl);
> >> >
> >> > -       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
> >> > +       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX ||
> >> > +           e1000e_vlan_used(adapter))
> >> >                 e1000e_vlan_strip_enable(adapter);
> >> >         else
> >> >                 e1000e_vlan_strip_disable(adapter);
> >>
> >> So if the VLAN tag stripping is disabled what happens that is causing
> >> the VLAN test to fail?  It sounds like this might be working around a
> >> kernel bug where a VLAN created on a device that supports hardware tag
> >> stripping only supports hardware tag stripping.  Maybe a better fix
> >> would be to add a fall back so if the VLAN tag is in the frame instead
> >> of stripped it still makes it to the correct spot.
> >
> > That's the main reason I labeled it as an RFC -- I wasn't sure exactly how
> > things were intended to work when the hardware stripping was disabled. It
> > seems quite plausible to me that this patch simply papers over the real
> > bug: lack of a functional software fallback. I'm not particularly up on
> > the vlan code just yet though, so I'm not yet sure where to poke next.
> > Suggestions welcomed. :)
> 
> Well the software fallback should be the call to skb_vlan_untag in
> __netif_receive_skb_core.  If that isn't being triggered then we
> should probably be fixing the files in the core code then.

So I've been poking at a debug-spew-laden kernel some, and skb_vlan_untag
is most definitely not getting called when rxvlan off is set. I'm still
poking around, trying to track down where things are going askew.

-- 
Jarod Wilson
jarod@redhat.com

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#1418637

FromJarod Wilson <jarod@redhat.com>
Date2016-06-09 23:00 +0200
Message-ID<rIfdv-360-7@gated-at.bofh.it>
In reply to#1418546
On Thu, Jun 09, 2016 at 02:02:04PM -0400, Jarod Wilson wrote:
> On Wed, Jun 01, 2016 at 03:31:46PM -0700, Alexander Duyck wrote:
> > On Wed, Jun 1, 2016 at 12:27 PM, Jarod Wilson <jarod@redhat.com> wrote:
> > > On Wed, Jun 01, 2016 at 07:31:53AM -0700, Alexander Duyck wrote:
> > >> On Tue, May 17, 2016 at 12:03 PM, Jarod Wilson <jarod@redhat.com> wrote:
> > >> > I've got a bug report about an e1000e interface, where a vlan interface is
> > >> > set up on top of it:
> > >> >
> > >> > $ ip link add link ens1f0 name ens1f0.99 type vlan id 99
> > >> > $ ip link set ens1f0 up
> > >> > $ ip link set ens1f0.99 up
> > >> > $ ip addr add 192.168.99.92 dev ens1f0.99
> > >> >
> > >> > At this point, I can ping another host on vlan 99, ip 192.168.99.91.
> > >> > However, if I do the following:
> > >> >
> > >> > $ ethtool -K ens1f0 rxvlan off
> > >> >
> > >> > Then no traffic passes on ens1f0.99. It comes back if I toggle rxvlan on
> > >> > again. I'm not sure if this is actually intended behavior, or if there's a
> > >> > lack of software vlan stripping fallback, or what, but things continue to
> > >> > work if I simply don't call e1000e_vlan_strip_disable() if there are
> > >> > active vlans (plagiarizing a function from the e1000 driver here) on the
> > >> > interface.
> > >> >
> > >> > Also slipped a related-ish fix to the kerneldoc text for
> > >> > e1000e_vlan_strip_disable here...
> > >> >
> > >> > CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> > >> > CC: intel-wired-lan@lists.osuosl.org
> > >> > CC: netdev@vger.kernel.org
> > >> > Signed-off-by: Jarod Wilson <jarod@redhat.com>
> > >> > ---
> > >> >  drivers/net/ethernet/intel/e1000e/netdev.c | 15 +++++++++++++--
> > >> >  1 file changed, 13 insertions(+), 2 deletions(-)
> > >> >
> > >> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > >> > index 75e6089..73f7452 100644
> > >> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > >> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > >> > @@ -154,6 +154,16 @@ void __ew32(struct e1000_hw *hw, unsigned long reg, u32 val)
> > >> >         writel(val, hw->hw_addr + reg);
> > >> >  }
> > >> >
> > >> > +static bool e1000e_vlan_used(struct e1000_adapter *adapter)
> > >> > +{
> > >> > +       u16 vid;
> > >> > +
> > >> > +       for_each_set_bit(vid, adapter->active_vlans, VLAN_N_VID)
> > >> > +               return true;
> > >> > +
> > >>
> > >> I'm pretty sure this is always going to return true if 8021q is loaded
> > >> because VLAN 0 is always added to the device even if no other VLANs
> > >> are in use.
> > >
> > > Ah, hadn't considered that, I just plucked it straight from e1000.
> > >
> > >> > +       return false;
> > >> > +}
> > >> > +
> > >> >  /**
> > >> >   * e1000_regdump - register printout routine
> > >> >   * @hw: pointer to the HW structure
> > >> > @@ -2789,7 +2799,7 @@ static void e1000e_vlan_filter_enable(struct e1000_adapter *adapter)
> > >> >  }
> > >> >
> > >> >  /**
> > >> > - * e1000e_vlan_strip_enable - helper to disable HW VLAN stripping
> > >> > + * e1000e_vlan_strip_disable - helper to disable HW VLAN stripping
> > >> >   * @adapter: board private structure to initialize
> > >> >   **/
> > >> >  static void e1000e_vlan_strip_disable(struct e1000_adapter *adapter)
> > >> > @@ -3443,7 +3453,8 @@ static void e1000e_set_rx_mode(struct net_device *netdev)
> > >> >
> > >> >         ew32(RCTL, rctl);
> > >> >
> > >> > -       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
> > >> > +       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX ||
> > >> > +           e1000e_vlan_used(adapter))
> > >> >                 e1000e_vlan_strip_enable(adapter);
> > >> >         else
> > >> >                 e1000e_vlan_strip_disable(adapter);
> > >>
> > >> So if the VLAN tag stripping is disabled what happens that is causing
> > >> the VLAN test to fail?  It sounds like this might be working around a
> > >> kernel bug where a VLAN created on a device that supports hardware tag
> > >> stripping only supports hardware tag stripping.  Maybe a better fix
> > >> would be to add a fall back so if the VLAN tag is in the frame instead
> > >> of stripped it still makes it to the correct spot.
> > >
> > > That's the main reason I labeled it as an RFC -- I wasn't sure exactly how
> > > things were intended to work when the hardware stripping was disabled. It
> > > seems quite plausible to me that this patch simply papers over the real
> > > bug: lack of a functional software fallback. I'm not particularly up on
> > > the vlan code just yet though, so I'm not yet sure where to poke next.
> > > Suggestions welcomed. :)
> > 
> > Well the software fallback should be the call to skb_vlan_untag in
> > __netif_receive_skb_core.  If that isn't being triggered then we
> > should probably be fixing the files in the core code then.
> 
> So I've been poking at a debug-spew-laden kernel some, and skb_vlan_untag
> is most definitely not getting called when rxvlan off is set. I'm still
> poking around, trying to track down where things are going askew.

Okay, so rxvlan is *supposed* to only impact the rx path, right? It's
looking like it is actually impacting the tx path too here. I actually
*do* see calls to skb_vlan_untag with rxvlan off, if I ping from an
external host, so it seems only the packets from the host with rxvlan
toggled off aren't escaping correctly for some reason.

-- 
Jarod Wilson
jarod@redhat.com

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#1418872

FromJarod Wilson <jarod@redhat.com>
Date2016-06-10 00:20 +0200
Message-ID<rIgsV-47V-1@gated-at.bofh.it>
In reply to#1418637
On Thu, Jun 09, 2016 at 04:55:01PM -0400, Jarod Wilson wrote:
> On Thu, Jun 09, 2016 at 02:02:04PM -0400, Jarod Wilson wrote:
> > On Wed, Jun 01, 2016 at 03:31:46PM -0700, Alexander Duyck wrote:
> > > On Wed, Jun 1, 2016 at 12:27 PM, Jarod Wilson <jarod@redhat.com> wrote:
> > > > On Wed, Jun 01, 2016 at 07:31:53AM -0700, Alexander Duyck wrote:
> > > >> On Tue, May 17, 2016 at 12:03 PM, Jarod Wilson <jarod@redhat.com> wrote:
> > > >> > I've got a bug report about an e1000e interface, where a vlan interface is
> > > >> > set up on top of it:
> > > >> >
> > > >> > $ ip link add link ens1f0 name ens1f0.99 type vlan id 99
> > > >> > $ ip link set ens1f0 up
> > > >> > $ ip link set ens1f0.99 up
> > > >> > $ ip addr add 192.168.99.92 dev ens1f0.99
> > > >> >
> > > >> > At this point, I can ping another host on vlan 99, ip 192.168.99.91.
> > > >> > However, if I do the following:
> > > >> >
> > > >> > $ ethtool -K ens1f0 rxvlan off
> > > >> >
> > > >> > Then no traffic passes on ens1f0.99. It comes back if I toggle rxvlan on
> > > >> > again. I'm not sure if this is actually intended behavior, or if there's a
> > > >> > lack of software vlan stripping fallback, or what, but things continue to
> > > >> > work if I simply don't call e1000e_vlan_strip_disable() if there are
> > > >> > active vlans (plagiarizing a function from the e1000 driver here) on the
> > > >> > interface.
> > > >> >
> > > >> > Also slipped a related-ish fix to the kerneldoc text for
> > > >> > e1000e_vlan_strip_disable here...
> > > >> >
> > > >> > CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> > > >> > CC: intel-wired-lan@lists.osuosl.org
> > > >> > CC: netdev@vger.kernel.org
> > > >> > Signed-off-by: Jarod Wilson <jarod@redhat.com>
> > > >> > ---
> > > >> >  drivers/net/ethernet/intel/e1000e/netdev.c | 15 +++++++++++++--
> > > >> >  1 file changed, 13 insertions(+), 2 deletions(-)
> > > >> >
> > > >> > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > >> > index 75e6089..73f7452 100644
> > > >> > --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> > > >> > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> > > >> > @@ -154,6 +154,16 @@ void __ew32(struct e1000_hw *hw, unsigned long reg, u32 val)
> > > >> >         writel(val, hw->hw_addr + reg);
> > > >> >  }
> > > >> >
> > > >> > +static bool e1000e_vlan_used(struct e1000_adapter *adapter)
> > > >> > +{
> > > >> > +       u16 vid;
> > > >> > +
> > > >> > +       for_each_set_bit(vid, adapter->active_vlans, VLAN_N_VID)
> > > >> > +               return true;
> > > >> > +
> > > >>
> > > >> I'm pretty sure this is always going to return true if 8021q is loaded
> > > >> because VLAN 0 is always added to the device even if no other VLANs
> > > >> are in use.
> > > >
> > > > Ah, hadn't considered that, I just plucked it straight from e1000.
> > > >
> > > >> > +       return false;
> > > >> > +}
> > > >> > +
> > > >> >  /**
> > > >> >   * e1000_regdump - register printout routine
> > > >> >   * @hw: pointer to the HW structure
> > > >> > @@ -2789,7 +2799,7 @@ static void e1000e_vlan_filter_enable(struct e1000_adapter *adapter)
> > > >> >  }
> > > >> >
> > > >> >  /**
> > > >> > - * e1000e_vlan_strip_enable - helper to disable HW VLAN stripping
> > > >> > + * e1000e_vlan_strip_disable - helper to disable HW VLAN stripping
> > > >> >   * @adapter: board private structure to initialize
> > > >> >   **/
> > > >> >  static void e1000e_vlan_strip_disable(struct e1000_adapter *adapter)
> > > >> > @@ -3443,7 +3453,8 @@ static void e1000e_set_rx_mode(struct net_device *netdev)
> > > >> >
> > > >> >         ew32(RCTL, rctl);
> > > >> >
> > > >> > -       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX)
> > > >> > +       if (netdev->features & NETIF_F_HW_VLAN_CTAG_RX ||
> > > >> > +           e1000e_vlan_used(adapter))
> > > >> >                 e1000e_vlan_strip_enable(adapter);
> > > >> >         else
> > > >> >                 e1000e_vlan_strip_disable(adapter);
> > > >>
> > > >> So if the VLAN tag stripping is disabled what happens that is causing
> > > >> the VLAN test to fail?  It sounds like this might be working around a
> > > >> kernel bug where a VLAN created on a device that supports hardware tag
> > > >> stripping only supports hardware tag stripping.  Maybe a better fix
> > > >> would be to add a fall back so if the VLAN tag is in the frame instead
> > > >> of stripped it still makes it to the correct spot.
> > > >
> > > > That's the main reason I labeled it as an RFC -- I wasn't sure exactly how
> > > > things were intended to work when the hardware stripping was disabled. It
> > > > seems quite plausible to me that this patch simply papers over the real
> > > > bug: lack of a functional software fallback. I'm not particularly up on
> > > > the vlan code just yet though, so I'm not yet sure where to poke next.
> > > > Suggestions welcomed. :)
> > > 
> > > Well the software fallback should be the call to skb_vlan_untag in
> > > __netif_receive_skb_core.  If that isn't being triggered then we
> > > should probably be fixing the files in the core code then.
> > 
> > So I've been poking at a debug-spew-laden kernel some, and skb_vlan_untag
> > is most definitely not getting called when rxvlan off is set. I'm still
> > poking around, trying to track down where things are going askew.
> 
> Okay, so rxvlan is *supposed* to only impact the rx path, right? It's
> looking like it is actually impacting the tx path too here. I actually
> *do* see calls to skb_vlan_untag with rxvlan off, if I ping from an
> external host, so it seems only the packets from the host with rxvlan
> toggled off aren't escaping correctly for some reason.

And this leads me to believe maybe the bit in the e1000 driver that
mentions explicitly that the hardware has no support for separate RX/TX
vlan accel toggling rings true for e1000e as well, and thus both
NETIF_F_HW_VLAN_CTAG_RX and NETIF_F_HW_VLAN_CTAG_TX need to be kept in
sync. Testing this theory out shortly...

-- 
Jarod Wilson
jarod@redhat.com

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#1418941

FromJarod Wilson <jarod@redhat.com>
Date2016-06-10 01:30 +0200
Message-ID<rIhyF-4Ya-3@gated-at.bofh.it>
In reply to#1418872
On Thu, Jun 09, 2016 at 06:17:45PM -0400, Jarod Wilson wrote:
> On Thu, Jun 09, 2016 at 04:55:01PM -0400, Jarod Wilson wrote:
> > On Thu, Jun 09, 2016 at 02:02:04PM -0400, Jarod Wilson wrote:
> > > On Wed, Jun 01, 2016 at 03:31:46PM -0700, Alexander Duyck wrote:
> > > > On Wed, Jun 1, 2016 at 12:27 PM, Jarod Wilson <jarod@redhat.com> wrote:
> > > > > On Wed, Jun 01, 2016 at 07:31:53AM -0700, Alexander Duyck wrote:
> > > > >> On Tue, May 17, 2016 at 12:03 PM, Jarod Wilson <jarod@redhat.com> wrote:
> > > > >> > I've got a bug report about an e1000e interface, where a vlan interface is
> > > > >> > set up on top of it:
> > > > >> >
> > > > >> > $ ip link add link ens1f0 name ens1f0.99 type vlan id 99
> > > > >> > $ ip link set ens1f0 up
> > > > >> > $ ip link set ens1f0.99 up
> > > > >> > $ ip addr add 192.168.99.92 dev ens1f0.99
> > > > >> >
> > > > >> > At this point, I can ping another host on vlan 99, ip 192.168.99.91.
> > > > >> > However, if I do the following:
> > > > >> >
> > > > >> > $ ethtool -K ens1f0 rxvlan off
> > > > >> >
> > > > >> > Then no traffic passes on ens1f0.99. It comes back if I toggle rxvlan on
> > > > >> > again. I'm not sure if this is actually intended behavior, or if there's a
> > > > >> > lack of software vlan stripping fallback, or what, but things continue to
> > > > >> > work if I simply don't call e1000e_vlan_strip_disable() if there are
> > > > >> > active vlans (plagiarizing a function from the e1000 driver here) on the
> > > > >> > interface.
...
> > Okay, so rxvlan is *supposed* to only impact the rx path, right? It's
> > looking like it is actually impacting the tx path too here. I actually
> > *do* see calls to skb_vlan_untag with rxvlan off, if I ping from an
> > external host, so it seems only the packets from the host with rxvlan
> > toggled off aren't escaping correctly for some reason.
> 
> And this leads me to believe maybe the bit in the e1000 driver that
> mentions explicitly that the hardware has no support for separate RX/TX
> vlan accel toggling rings true for e1000e as well, and thus both
> NETIF_F_HW_VLAN_CTAG_RX and NETIF_F_HW_VLAN_CTAG_TX need to be kept in
> sync. Testing this theory out shortly...

We have a winner. If I make sure the TX flag gets toggled too, ping
continues to work after disabling rxvlan.

$ ping 192.168.99.91
PING 192.168.99.91 (192.168.99.91) 56(84) bytes of data.
64 bytes from 192.168.99.91: icmp_seq=1 ttl=64 time=0.591 ms
64 bytes from 192.168.99.91: icmp_seq=2 ttl=64 time=0.335 ms
64 bytes from 192.168.99.91: icmp_seq=3 ttl=64 time=0.417 ms
^C
--- 192.168.99.91 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.335/0.447/0.591/0.109 ms

$ sudo ethtool -K ens1f0 rxvlan off
Actual changes:
rx-vlan-offload: off
tx-vlan-offload: off [requested on]

$ ping 192.168.99.91
PING 192.168.99.91 (192.168.99.91) 56(84) bytes of data.
64 bytes from 192.168.99.91: icmp_seq=1 ttl=64 time=0.327 ms
64 bytes from 192.168.99.91: icmp_seq=2 ttl=64 time=0.393 ms
64 bytes from 192.168.99.91: icmp_seq=3 ttl=64 time=0.424 ms
^C
--- 192.168.99.91 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 1999ms
rtt min/avg/max/mdev = 0.327/0.381/0.424/0.043 ms

I'll clean things up and submit a patch tonight or tomorrow.

-- 
Jarod Wilson
jarod@redhat.com

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