Somnath,

On 12/31/19 5:15 AM, Somnath Kotur wrote:

Andrew,

On Tue, Dec 24, 2019 at 3:23 PM Andrew Rybchenko
[off-list ref] wrote:

quoted

On 12/24/19 6:16 AM, Somnath Kotur wrote:

quoted

Given that we haven't heard any objection from anyone in a while on
this ...can we get this in please?

I'm sorry, but have you seen below?
It means that PKT_RX_QINQ_STRIPPED, PKT_RX_QINQ, PKT_RX_VLAN
and PKT_RX_VLAN_STRIPPED must be clarified.

OK, not sure I understood what is the next action here? Will you or someone
from the main tree maintainers be sending out a patch with this clarification?

Please, send non-RCF version of the patch which fixes
PKT_RX_QINQ_STRIPPED and PKT_RX_QINQ description.
PKT_RX_QINQ must not claim that both VLAN headers
have been stripped in the case of PKT_RX_QINQ_STRIPPED.

I think that VLAN should be used instead of "vlan" in description
as well as TCI instead of "tci". Also vlans -> VLANs.

quoted

It sounds like change of semantics in order to resolve the
problem, but anyway it is still a small change of semantics.

May be dropped.

quoted

BTW, it is better to make summary human readable and avoid
PKT_RX_QINQ_STRIPPED (I guess check-git-log.sh yells on it).

Please, don't forget about it as well.

quoted

Also RFC patch cannot be applied, non-RFC version is required.

CC main tree maintainers.

quoted

Thanks

On Mon, Dec 16, 2019 at 2:43 PM Andrew Rybchenko
[off-list ref] wrote:

quoted

On 12/16/19 11:47 AM, Somnath Kotur wrote:

quoted

On Mon, Dec 16, 2019 at 12:01 PM Andrew Rybchenko
[off-list ref] wrote:

quoted

On 12/16/19 6:16 AM, Somnath Kotur wrote:

quoted

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 <redacted>
Signed-off-by: JP Lee <redacted>
---
 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?

Yes.

quoted

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 ?

Ah, it looks like I understand now that the problem is in
PKT_RX_QINQ description which claims that TCI is saved in
mbuf->vlan_tci_outer and PKT_RX_QINQ_STRIPPED means that
both VLAN tags are stripped regardless (PKT_RX_VLAN_STRIPPED).
Moreover PKT_RX_QINQ_STRIPPED requires PKT_RX_VLAN_STRIPPED.

It means that PKT_RX_QINQ_STRIPPED, PKT_RX_QINQ, PKT_RX_VLAN
and PKT_RX_VLAN_STRIPPED must be clarified.

I'm not sure, but it looks like it could affect net/dpaa2,
so I'm including driver maintainers in CC.