Hi Olivier, On 12/27/19 5:50 PM, Olivier Matz wrote: > Hi, > > On Tue, Dec 24, 2019 at 12:53:21PM +0300, Andrew Rybchenko wrote: >> On 12/24/19 6:16 AM, Somnath Kotur wrote: >>> 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. >> >> It sounds like change of semantics in order to resolve the >> problem, but anyway it is still a small change of semantics. > Let's take this packet: > packet = ether | outer-vlan | inner-vlan | ... > > The possible mbufs received from a PMD, depending on configuration, are: > > 1/ no flag (no offload) > > 2/ PKT_RX_VLAN > packet data is unmodified > m->vlan_tci=outer-vlan > > 3/ PKT_RX_VLAN | PKT_RX_VLAN_STRIPPED > outer-vlan is removed from packet data > m->vlan_tci=outer-vlan > > 4/ PKT_RX_VLAN | PKT_RX_QINQ > packet data is unmodified > m->vlan_tci_outer=outer-vlan > m->vlan_tci=inner-vlan > > 5/ PKT_RX_VLAN | PKT_RX_VLAN_STRIPPED | PKT_RX_QINQ > > from PKT_RX_VLAN_STRIPPED: > A vlan has been stripped by the hardware and its tci is saved in > mbuf->vlan_tci. > from PKT_RX_QINQ: > The RX packet is a double VLAN, and the outer tci has been > saved in in mbuf->vlan_tci_outer. > > To me, it means: > > inner-vlan is removed from packet data > m->vlan_tci_outer=outer-vlan > m->vlan_tci=inner-vlan
Yes, I agree that such behaviour is logical (since PKT_RX_VLAN_STRIPPED is bound to PKT_RX_VLAN => m->vlan_tci). My understanding was wrong (see below) since I thought that outer-vlan is saved in vlan_tci in this case (since only one is stripped). > 6/ PKT_RX_VLAN | PKT_RX_VLAN_STRIPPED | PKT_RX_QINQ | PKT_RX_QINQ_STRIPPED > both outer-vlan and inner-vlan removed from packet data > m->vlan_tci_outer=outer-vlan > m->vlan_tci=inner-vlan > > Other flag combinations are not supported. > The proposed patch documents that this new flag combination is now allowed: > > 7/ PKT_RX_VLAN | PKT_RX_QINQ | PKT_RX_QINQ_STRIPPED > outer-vlan is removed from packet data > m->vlan_tci_outer=outer-vlan > m->vlan_tci=inner-vlan > > Except if I missed something, I don't see any semantic change in > the previously supported cases. Yes, I agree. > I think we should by the way clarify what happens in 5/, probably by > saying somewhere that as soon as PKT_RX_QINQ is set, PKT_RX_VLAN* > refer to inner vlan. Yes, it would be good, since exactly this cases confuses me. Many thanks for clarification. >> BTW, it is better to make summary human readable and avoid >> PKT_RX_QINQ_STRIPPED (I guess check-git-log.sh yells on it). >> >> Also RFC patch cannot be applied, non-RFC version is required. >> >> CC main tree maintainers. >> >>> Thanks >>> >>> On Mon, Dec 16, 2019 at 2:43 PM Andrew Rybchenko >>> <arybche...@solarflare.com> wrote: >>>> On 12/16/19 11:47 AM, Somnath Kotur wrote: >>>>> On Mon, Dec 16, 2019 at 12:01 PM Andrew Rybchenko >>>>> <arybche...@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.ko...@broadcom.com> >>>>>>> Signed-off-by: JP Lee <jongpil....@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? >>>> Yes. >>>> >>>>> 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.
