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From: Somnath Kotur <somnath.kotur@broadcom.com>
To: Andrew Rybchenko <arybchenko@solarflare.com>
Cc: dev <dev@dpdk.org>, Ferruh Yigit <ferruh.yigit@intel.com>,
	 Olivier Matz <olivier.matz@6wind.com>
Subject: Re: [dpdk-dev] [RFC PATCH] mbuf: fix to update documentation of PKT_RX_QINQ_STRIPPED
Date: Mon, 16 Dec 2019 14:17:37 +0530
Message-ID: <CAOBf=muFZLXDYoqDQdZP-SjC+mx2Okpju8539s+-fpHK-xcu=w@mail.gmail.com> (raw)
In-Reply-To: <68e1721c-4051-0451-185d-39344a026a38@solarflare.com>

On Mon, Dec 16, 2019 at 12:01 PM Andrew Rybchenko
<arybchenko@solarflare.com> wrote:
>
> On 12/16/19 6:16 AM, Somnath Kotur wrote:
> > Certain hardware may be able to strip and/or save only the outermost
> > VLAN instead of both the VLANs in the mbuf in a QinQ scenario.
> > To handle such cases, we could re-interpret setting of just PKT_RX_QINQ_STRIPPED
> > to indicate that only the outermost VLAN has been stripped by the hardware and
> > saved in mbuf->vlan_tci_outer.
> > Only When both PKT_RX_QINQ_STRIPPED and PKT_RX_VLAN_STRIPPED are set, the 2 vlans
> > have been stripped by the hardware and their tci are saved in mbuf->vlan_tci (inner)
> > and mbuf->vlan_tci_outer (outer).
> >
> > Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
> > Signed-off-by: JP Lee <jongpil.lee@broadcom.com>
> > ---
> >  lib/librte_mbuf/rte_mbuf_core.h | 15 +++++++++++----
> >  1 file changed, 11 insertions(+), 4 deletions(-)
> >
> > diff --git a/lib/librte_mbuf/rte_mbuf_core.h b/lib/librte_mbuf/rte_mbuf_core.h
> > index 9a8557d..db1070b 100644
> > --- a/lib/librte_mbuf/rte_mbuf_core.h
> > +++ b/lib/librte_mbuf/rte_mbuf_core.h
> > @@ -124,12 +124,19 @@
> >  #define PKT_RX_FDIR_FLX      (1ULL << 14)
> >
> >  /**
> > - * The 2 vlans have been stripped by the hardware and their tci are
> > - * saved in mbuf->vlan_tci (inner) and mbuf->vlan_tci_outer (outer).
> > + * The outer vlan has been stripped by the hardware and their tci are
> > + * saved in mbuf->vlan_tci_outer (outer).
> >   * This can only happen if vlan stripping is enabled in the RX
> >   * configuration of the PMD.
> > - * When PKT_RX_QINQ_STRIPPED is set, the flags (PKT_RX_VLAN |
> > - * PKT_RX_VLAN_STRIPPED | PKT_RX_QINQ) must also be set.
> > + * When PKT_RX_QINQ_STRIPPED is set, the flags (PKT_RX_VLAN |  PKT_RX_QINQ)
> > + * must also be set.
> > + * When both PKT_RX_QINQ_STRIPPED and PKT_RX_VLAN_STRIPPED are set, the 2 vlans
> > + * have been stripped by the hardware and their tci are saved in
> > + * mbuf->vlan_tci (inner) and mbuf->vlan_tci_outer (outer).
> > + * This can only happen if vlan stripping is enabled in the RX configuration
> > + * of the PMD.
> > + * When PKT_RX_QINQ_STRIPPED and PKT_RX_VLAN_STRIPPED are set,
> > + * (PKT_RX_VLAN | PKT_RX_QINQ) must also be set.
> >   */
> >  #define PKT_RX_QINQ_STRIPPED (1ULL << 15)
> >
>
> I always thought that PKT_RX_VLAN_STRIPPED means *one* VLAN
> stripped regardless if it is outer (if the packet is double
> tagged) or inner (if only one VLAN tag was present).
>
> That's why PKT_RX_QINQ_STRIPPED description says that *two*
> VLANs have been stripped.
>
> What is the problem with such approach?
The problem is that RX_VLAN_STRIPPED implies that the stripped VLAN
(outer or inner) is saved in mbuf->vlan_tci, correct?
There is no way to convey that it is in QinQ mode and yet only outer
VLAN has been stripped and saved in mbuf->vlan_tci_outer ?

  reply	other threads:[~2019-12-16  8:47 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-16  3:16 Somnath Kotur
2019-12-16  6:31 ` Andrew Rybchenko
2019-12-16  8:47   ` Somnath Kotur [this message]
2019-12-16  9:13     ` Andrew Rybchenko
2019-12-24  3:16       ` Somnath Kotur
2019-12-24  9:53         ` Andrew Rybchenko
2019-12-27 14:50           ` Olivier Matz
2019-12-31  2:13             ` Somnath Kotur
2020-01-02 12:57             ` Andrew Rybchenko
2019-12-31  2:15           ` Somnath Kotur
2020-01-02 13:04             ` Andrew Rybchenko
2020-01-06  8:36               ` Somnath Kotur

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