Hi Olivier,
On Fri, May 15, 2020 at 07:27:46PM +0530, Nithin Dabilpuram wrote:
> On Fri, May 15, 2020 at 10:30:30AM +0000, Ananyev, Konstantin wrote:
> >
> > > On Thu, May 14, 2020 at 10:29:31PM +0200, Olivier Matz wrote:
> > > > Hi Nithin,
> > > >
> > > > On Tue, May 05, 2020 at 11:49:20AM +0530, Nithin Dabilpuram wrote:
> > > > > On Mon, May 04, 2020 at 02:27:35PM +0200, Olivier Matz wrote:
> > > > > > On Mon, May 04, 2020 at 03:34:57PM +0530, Nithin Dabilpuram wrote:
> > > > > > > On Mon, May 04, 2020 at 11:16:40AM +0200, Olivier Matz wrote:
> > > > > > > > On Mon, May 04, 2020 at 01:57:06PM +0530, Nithin Dabilpuram
> > > > > > > > wrote:
> > > > > > > > > Hi Olivier,
> > > > > > > > >
> > > > > > > > > On Mon, May 04, 2020 at 10:06:34AM +0200, Olivier Matz wrote:
> > > > > > > > > > External Email
> > > > > > > > > >
> > > > > > > > > > ----------------------------------------------------------------------
> > > > > > > > > > Hi,
> > > > > > > > > >
> > > > > > > > > > On Fri, May 01, 2020 at 04:48:21PM +0530, Jerin Jacob wrote:
> > > > > > > > > > > On Fri, Apr 17, 2020 at 12:53 PM Nithin Dabilpuram
> > > > > > > > > > > <nithind1...@gmail.com> wrote:
> > > > > > > > > > > >
> > > > > > > > > > > > From: Nithin Dabilpuram <ndabilpu...@marvell.com>
> > > > > > > > > > > >
> > > > > > > > > > > > Introduce PKT_TX_MARK_IP_DSCP, PKT_TX_MARK_IP_ECN
> > > > > > > > > > > > and PKT_TX_MARK_VLAN_DEI Tx offload flags to support
> > > > > > > > > > > > packet marking.
> > > > > > > > > > > >
> > > > > > > > > > > > When packet marking feature in Traffic manager is
> > > > > > > > > > > > enabled,
> > > > > > > > > > > > application has to the use the three new flags to
> > > > > > > > > > > > indicate
> > > > > > > > > > > > to PMD on whether packet marking needs to be enabled on
> > > > > > > > > > > > the
> > > > > > > > > > > > specific mbuf or not. By setting the three flags, it is
> > > > > > > > > > > > assumed by PMD that application has already verified the
> > > > > > > > > > > > applicability of marking on that specific packet and
> > > > > > > > > > > > PMD need not perform further checks as per RFC.
> > > > > > > > > > > >
> > > > > > > > > > > > Signed-off-by: Krzysztof Kanas <kka...@marvell.com>
> > > > > > > > > > > > Signed-off-by: Nithin Dabilpuram
> > > > > > > > > > > > <ndabilpu...@marvell.com>
> > > > > > > > > > >
> > > > > > > > > > > None of the ethdev TM driver implementations has
> > > > > > > > > > > supported packet
> > > > > > > > > > > marking support.
> > > > > > > > > > > rte_tm and rte_mbuf maintainers(Christian, Oliver), Could
> > > > > > > > > > > you review this patch?
> > > > > > > > > >
> > > > > > > > > > As you know, the number of mbuf flags is limited (only 18
> > > > > > > > > > bits are
> > > > > > > > > > remaining), so I think we should use them with care, i.e.
> > > > > > > > > > for features
> > > > > > > > > > that are generic enough.
> > > > > > > > >
> > > > > > > > > I agree, but I believe this is one of the basic flags needed
> > > > > > > > > like other
> > > > > > > > > Tx checksum offload flags (like PKT_TX_IP_CKSUM, PKT_TX_IPV4,
> > > > > > > > > etc) which
> > > > > > > > > are needed to identify on which packets HW should/can apply
> > > > > > > > > packet marking.
> > > > > > > >
> > > > > > > > PKT_TX_IP_CKSUM tells the hardware to offload the checksum
> > > > > > > > calculation. This is pretty straightforward and there is no
> > > > > > > > other
> > > > > > > > dependency than the offload feature advertised by the PMD.
> > > > > > > >
> > > > > > > > I'm sorry, I have not a lot of experience with rte_tm.h, so it's
> > > > > > > > difficult for me to have a global view of what is done for
> > > > > > > > instance when
> > > > > > > > PKT_TX_MARK_VLAN_DEI is set, and what happens when it is not
> > > > > > > > set.
> > > > > > > >
> > > > > > > > Can you confirm that my understanding below is correct? (or
> > > > > > > > correct me
> > > > > > > > where I'm wrong)
> > > > > > > >
> > > > > > > > Before your patch:
> > > > > > > > - the application enables the port and traffic manager on it
> > > > > > > > - the application calls rte_tm_mark_vlan_dei() to select which
> > > > > > > > traffic
> > > > > > > > class must be marked
> > > > > > > > - when a packet is transmitted, the traffic class is determined
> > > > > > > > by the
> > > > > > > > hardware, and if the hardware recognizes a VLAN packet, the
> > > > > > > > VLAN DEI
> > > > > > > > bit is set depending on traffic class
> > > > > > > >
> > > > > > > > The problem is for packets that cannot be recognized by the
> > > > > > > > hardware,
> > > > > > > > correct?
> > > > > > >
> > > > > > > Yes. Octeontx2 HW always depends on application knowledge instead
> > > > > > > of walking
> > > > > > > through all the layers of packet data in Tx to identify what
> > > > > > > packet it is
> > > > > > > and where the l2, l3, l4 headers start for performance reasons.
> > > > > > >
> > > > > > > I believe there are other hardware too that have the same
> > > > > > > expectation
> > > > > > > and hence we have a need for PKT_TX_IPv4, PKT_TX_IPv6 kind of
> > > > > > > flags.
> > > > > > >
> > > > > > > Hence we want to make use of mbuf:tx_offload field and PKT_TX_*
> > > > > > > flags
> > > > > > > for identifying the packet and knowing what are its l2,l3,l4
> > > > > > > offsets.
> > > > > >
> > > > > > The objective is to give an indication to the hardware that the
> > > > > > packet has:
> > > > > > - an 802.1q header at offset X for PKT_TX_MARK_VLAN_DEI
> > > > > > - an IP/IPv6 header at offset X for PKT_TX_MARK_IP_DSCP
> > > > > > - an IP/IPv6 header at offset X and a TCP/SCTP header at offset Y
> > > > > > for
> > > > > > PKT_TX_MARK_IP_ECN
> > > > > >
> > > > > > Just to be sure I'm getting the point, would it also work if with
> > > > > > flags
> > > > > > like this:
> > > > > >
> > > > > > - an 802.1q header at offset X for PKT_TX_HAS_VLAN
> > > > > > - an IP/IPv6 header at offset X for PKT_TX_IPv4 or PKT_TX_IPv6
> > > > > > - a TCP/SCTP header at offset Y for PKT_TX_TCP/PKT_TX_SCTP (implies
> > > > > > PKT_TX_IPv4 or PKT_TX_IPv6)
> > > > > >
> > > > > > The underlying question is: do we need the flags to only describe
> > > > > > the
> > > > > > content of the packet or do the flag also indicate that an action
> > > > > > has to
> > > > > > be done?
> > > > >
> > > > > If we don't have a specific action based flag, then in future it
> > > > > might collide
> > > > > with other functionality and we will not be able to choose that
> > > > > specific
> > > > > offload. All the existing features are having specific flags, like
> > > > > TSO,
> > > > > CSUM.
> > > > >
> > > > > RFC wise, even when marking in enabled and packet is coloured, not
> > > > > all packets
> > > > > can be marked.
> > > > > For example when IP DSCP marking(RFC 2597) is enabled, marking is
> > > > > defined
> > > > > only with below 12 code points out of 64 code points (6 bits of DSCP).
> > > > >
> > > > > Class 1 Class 2 Class 3 Class 4
> > > > > +----------+----------+----------+----------+
> > > > > Low Drop Prec | 001010 | 010010 | 011010 | 100010 |
> > > > > Medium Drop Prec | 001100 | 010100 | 011100 | 100100 |
> > > > > High Drop Prec | 001110 | 010110 | 011110 | 100110 |
> > > > > +----------+----------+----------+----------+
> > > > >
> > > > > All other combinations of DSCP value can be used for some other
> > > > > purposes
> > > > > and hence packets with those values shouldn't be marked.
> > > > > Similar is the case with IP ECN marking for TCP/SCTP(RFC 3168).
> > > > >
> > > > > Having PMD or HW to check if the packet falls in the said class and
> > > > > then do
> > > > > marking will impact performance. Since application actually fills
> > > > > those values
> > > > > in packet, it will be more easy for them to say.
> > > > >
> > > > > >
> > > > > > > > So your patch is a way to force the hardware to recognize mark
> > > > > > > > set the
> > > > > > > > VLAN DEI on packets that are not recognized as VLAN packets?
> > > > > > > >
> > > > > > > > How the is traffic class of the packet determined?
> > > > > > >
> > > > > > > Packet is coloured based on Single Rate[1] or Dual Rate[2]
> > > > > > > Shaping result
> > > > > > > and packet color determines traffic class. The exact behavior of
> > > > > > > packet color to traffic class mapping is mentioned in TM spec
> > > > > > > based on
> > > > > > > few other RFC's.
> > > > > > >
> > > > > > > [1] https://urldefense.proofpoint.com/v2/url?u=https-
> > > 3A__tools.ietf.org_html_rfc2697&d=DwIBAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=FZ_tPCbgFOh18zwRPO9H0yDx8VW38vuapifdDfc8SFQ&m=
> > > pJDciSXpMy6TawycjvpYj_Jq5M5j_ywqhU8-keRI_ac&s=05emGNkz3Qat3dtZIbEsmQDC5y9-tU9yItHX0x1aaJU&e=
> > > > > > > [2] https://urldefense.proofpoint.com/v2/url?u=https-
> > > 3A__tools.ietf.org_html_rfc2698&d=DwIBAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=FZ_tPCbgFOh18zwRPO9H0yDx8VW38vuapifdDfc8SFQ&m=
> > > pJDciSXpMy6TawycjvpYj_Jq5M5j_ywqhU8-keRI_ac&s=3VN2dIGSDt4vWM-FpPOOf-8SeVShl_t7QpXRU6Zw460&e=
> > > > > >
> > > > > > OK, so the traffic class does not depend on the packet type?
> > > > > Yes it doesn't. But where to update the traffic class is specific to
> > > > > packet
> > > > > type like DEI bit in VLAN or ECN field in IPv4/IPv6 or DSCP field in
> > > > > IPv4/IPv6.
> > > > > Also ECN marking is only valid for TCP/SCTP packets.
> > > > >
> > > > > >
> > > > > >
> > > > > > > > > > From what I understand, this feature is bound to octeontx2,
> > > > > > > > > > so using a
> > > > > > > > > > mbuf dynamic flag would make more sense here. There are
> > > > > > > > > > some examples in
> > > > > > > > > > dpdk repository, just grep for "dynflag".
> > > > > > > > >
> > > > > > > > > This is not octeontx2 specific flag but any "packet marking
> > > > > > > > > feature" enabled
> > > > > > > > > PMD would need these flags to identify on which packets
> > > > > > > > > marking needs to be
> > > > > > > > > done. This is the first PMD that supports packet marking
> > > > > > > > > feature and
> > > > > > > > > hence it was not exposed earlier.
> > > > > > > > >
> > > > > > > > > For example to mark VLAN DEI, PMD cannot always assume that
> > > > > > > > > there is preexisting
> > > > > > > > > VLAN header from Byte 12 as there is no gaurantee that
> > > > > > > > > ethernet header
> > > > > > > > > always starts at Byte 0 (Custom headers before ethernet hdr).
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > Also, I think that the feature availability should be
> > > > > > > > > > advertised through
> > > > > > > > > > an ethdev offload, so an application can know at
> > > > > > > > > > initialization time
> > > > > > > > > > that these flags can be used.
> > > > > > > > >
> > > > > > > > > Feature availablity is already part of TM spec in rte_tm.h
> > > > > > > > > struct rte_tm_capabilities:mark_vlan_dei_supported
> > > > > > > > > struct rte_tm_capabilities:mark_ip_ecn_[sctp|tcp]_supported
> > > > > > > > > struct rte_tm_capabilities:mark_ip_dscp_supported
> > > > > > > >
> > > > > > > > Does this mean that any driver advertising this existing
> > > > > > > > feature flag
> > > > > > > > has to support the new mbuf flags too? Shouldn't we have a
> > > > > > > > specific
> > > > > > > > feature for it?
> > > > > > >
> > > > > > > Yes, I thought PMD's need to support both.
> > > > > > > I'm fine adding specific feature flag for the offload flags alone
> > > > > > > if you insist or if there are other PMD's which don't need the
> > > > > > > offload flags
> > > > > > > for packet marking. I was not able to find out about other PMD's
> > > > > > > as
> > > > > > > none of the existing PMD's support packet marking.
> > > > > >
> > > > > > Do you suggest that the behavior of the traffic manager marking
> > > > > > should
> > > > > > be:
> > > > > >
> > > > > > a- the hardware tries to recognize tx packets, and mark them
> > > > > > accordingly. What packets are recognized depend on hardware.
> > > > > > b- if the mbuf has a specific flag, it helps the PMD and hardware to
> > > > > > recognize packets, so it can mark packets.
> > > > > >
> > > > > > For an application, a- is difficult to apprehend as it will be
> > > > > > dependent
> > > > > > on hardware.
> > > > > >
> > > > > > Or do you suggest that packets should only be marked if there is a
> > > > > > mbuf
> > > > > > flag? (only b-)
> > > > > Yes, I believe b- is the right thing.
> > > > >
> > > > > >
> > > > > > Do you confirm that there is no support at all for this feature
> > > > > > today?
> > > > > > I mean, what was the usage of rte_tm_mark_vlan_dei() these last 3
> > > > > > years?
> > > > >
> > > > > Yes, it was not implemented/used. Because of such reasons, rte_tm.h is
> > > > > supposed to be experimental but was mistakenly marked stable.
> > > > > You can see related discussion in below threads about marking rte_tm.h
> > > > > experimental again in v20.11.
> > > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__mails.dpdk.org_archives_dev_2020-
> > > 2DApril_164970.html&d=DwIBAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=FZ_tPCbgFOh18zwRPO9H0yDx8VW38vuapifdDfc8SFQ&m=myqGwnIHN
> > > jN9IP7urxcVAB384qKoxlmm00p1gS7ttbw&s=-o2E-F9aHy3mrQw6xgO__RPXY9t8s3yjJn81X6Ius3k&e=
> > > > > https://urldefense.proofpoint.com/v2/url?u=https-3A__mails.dpdk.org_archives_dev_2020-
> > > 2DMay_166221.html&d=DwIBAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=FZ_tPCbgFOh18zwRPO9H0yDx8VW38vuapifdDfc8SFQ&m=myqGwnIHNj
> > > N9IP7urxcVAB384qKoxlmm00p1gS7ttbw&s=gTKSzMmlhE75x4TP8IJB7NP5MVO-zxjmNRQ9bZ6MxwI&e=
> > > >
> > > > Thank you for the explanations. I also think b- is a better choice.
> > > >
> > > > I don't see any better approach than having a mbuf flag. However, I'm
> > > > still not fully convinced that a dynamic flag won't do the job. Taking
> > > > 3 additional flags (among 18 remaing) for this feature also means that
> > > > we have 3 flags less for dynamic flags for all applications, even for
> > > > applications that will not use this feature.
> >
> > I also share Olivier's concern about consuming 3 bits in ol_flags for that
> > feature.
> > Can it probably be squeezed somehow?
> > Let say we reserve one flag that this information is present or not, and
> > re-use one of rx-only fields for store additional information (packet_type,
> > or so).
> > Or might be some other approach.
>
> We are fine with this approach where we define one bit in Tx offloads for pkt
> marking and and 3 bits reused from Rx offload flags area.
>
> For example:
>
> @@ -186,10 +186,16 @@ extern "C" {
>
> /* add new RX flags here, don't forget to update PKT_FIRST_FREE */
>
> +/* Reused Rx offload bits for Tx offloads */
> +#define PKT_X_TX_MARK_VLAN_DEI (1ULL << 0)
> +#define PKT_X_TX_MARK_IP_DSCP (1ULL << 1)
> +#define PKT_X_TX_MARK_IP_ECN (1ULL << 2)
> +
> #define PKT_FIRST_FREE (1ULL << 23)
> -#define PKT_LAST_FREE (1ULL << 40)
> +#define PKT_LAST_FREE (1ULL << 39)
>
> /* add new TX flags here, don't forget to update PKT_LAST_FREE */
> +#define PKT_TX_MARK_EN (1ULL << 40)
>
> Is this fine ?
Any thoughts on this approach which uses only 1 bit in Tx flags out of 18
and reuse unused Rx flag bits ?
>
>
> >
> > > >
> > > > Would it be a problem to use a dynamic flag in this case?
> > > Since packet marking feature itself is already part of spec,
> > > if we move the flags to PMD specific dynamic flag, then it creates a
> > > confusion.
> > >
> > > It is not the case of a custom feature supported by a specific PMD.
> > > I believe when other PMD's implement packet marking, the same flags will
> > > suffice.
> > > >
> > > > Thanks,
> > > > Olivier
> > > >
> > > >
> > > > >
> > > > > Thanks
> > > > > Nithin
> > > > >
> > > > > >
> > > > > > Thanks,
> > > > > > Olivier
> > > > > >
> > > > > >
> > > > > > >
> > > > > > > >
> > > > > > > > Please also see few comments below.
> > > > > > > >
> > > > > > > > > > > > ---
> > > > > > > > > > > > doc/guides/nics/features.rst | 14 ++++++++++++++
> > > > > > > > > > > > lib/librte_mbuf/rte_mbuf.c | 6 ++++++
> > > > > > > > > > > > lib/librte_mbuf/rte_mbuf_core.h | 36
> > > > > > > > > > > > ++++++++++++++++++++++++++++++++++--
> > > > > > > > > > > > 3 files changed, 54 insertions(+), 2 deletions(-)
> > > > > > > > > > > >
> > > > > > > > > > > > diff --git a/doc/guides/nics/features.rst
> > > > > > > > > > > > b/doc/guides/nics/features.rst
> > > > > > > > > > > > index edd21c4..bc978fb 100644
> > > > > > > > > > > > --- a/doc/guides/nics/features.rst
> > > > > > > > > > > > +++ b/doc/guides/nics/features.rst
> > > > > > > > > > > > @@ -913,6 +913,20 @@ Supports to get Rx/Tx packet burst
> > > > > > > > > > > > mode information.
> > > > > > > > > > > > * **[implements] eth_dev_ops**: ``rx_burst_mode_get``,
> > > > > > > > > > > > ``tx_burst_mode_get``.
> > > > > > > > > > > > * **[related] API**: ``rte_eth_rx_burst_mode_get()``,
> > > > > > > > > > > > ``rte_eth_tx_burst_mode_get()``.
> > > > > > > > > > > >
> > > > > > > > > > > > +..
> > > > > > > > > > > > _nic_features_traffic_manager_packet_marking_offload:
> > > > > > > > > > > > +
> > > > > > > > > > > > +Traffic Manager Packet marking offload
> > > > > > > > > > > > +--------------------------------------
> > > > > > > > > > > > +
> > > > > > > > > > > > +Supports enabling a packet marking offload specific
> > > > > > > > > > > > mbuf.
> > > > > > > > > > > > +
> > > > > > > > > > > > +* **[uses] mbuf**:
> > > > > > > > > > > > ``mbuf.ol_flags:PKT_TX_MARK_IP_DSCP``,
> > > > > > > > > > > > + ``mbuf.ol_flags:PKT_TX_MARK_IP_ECN``,
> > > > > > > > > > > > ``mbuf.ol_flags:PKT_TX_MARK_VLAN_DEI``,
> > > > > > > > > > > > + ``mbuf.ol_flags:PKT_TX_IPV4``,
> > > > > > > > > > > > ``mbuf.ol_flags:PKT_TX_IPV6``.
> > > > > > > > > > > > +* **[uses] mbuf**: ``mbuf.l2_len``.
> > > > > > > > > > > > +* **[related] API**: ``rte_tm_mark_ip_dscp()``,
> > > > > > > > > > > > ``rte_tm_mark_ip_ecn()``,
> > > > > > > > > > > > + ``rte_tm_mark_vlan_dei()``.
> > > > > > > > > > > > +
> > > > > > > > > > > > .. _nic_features_other:
> > > > > > > > > > > >
> > > > > > > > > > > > Other dev ops not represented by a Feature
> > > > > > > > > > > > diff --git a/lib/librte_mbuf/rte_mbuf.c
> > > > > > > > > > > > b/lib/librte_mbuf/rte_mbuf.c
> > > > > > > > > > > > index cd5794d..5c6896d 100644
> > > > > > > > > > > > --- a/lib/librte_mbuf/rte_mbuf.c
> > > > > > > > > > > > +++ b/lib/librte_mbuf/rte_mbuf.c
> > > > > > > > > > > > @@ -880,6 +880,9 @@ const char
> > > > > > > > > > > > *rte_get_tx_ol_flag_name(uint64_t mask)
> > > > > > > > > > > > case PKT_TX_SEC_OFFLOAD: return
> > > > > > > > > > > > "PKT_TX_SEC_OFFLOAD";
> > > > > > > > > > > > case PKT_TX_UDP_SEG: return "PKT_TX_UDP_SEG";
> > > > > > > > > > > > case PKT_TX_OUTER_UDP_CKSUM: return
> > > > > > > > > > > > "PKT_TX_OUTER_UDP_CKSUM";
> > > > > > > > > > > > + case PKT_TX_MARK_VLAN_DEI: return
> > > > > > > > > > > > "PKT_TX_MARK_VLAN_DEI";
> > > > > > > > > > > > + case PKT_TX_MARK_IP_DSCP: return
> > > > > > > > > > > > "PKT_TX_MARK_IP_DSCP";
> > > > > > > > > > > > + case PKT_TX_MARK_IP_ECN: return
> > > > > > > > > > > > "PKT_TX_MARK_IP_ECN";
> > > > > > > > > > > > default: return NULL;
> > > > > > > > > > > > }
> > > > > > > > > > > > }
> > > > > > > > > > > > @@ -916,6 +919,9 @@ rte_get_tx_ol_flag_list(uint64_t
> > > > > > > > > > > > mask, char *buf, size_t buflen)
> > > > > > > > > > > > { PKT_TX_SEC_OFFLOAD,
> > > > > > > > > > > > PKT_TX_SEC_OFFLOAD, NULL },
> > > > > > > > > > > > { PKT_TX_UDP_SEG, PKT_TX_UDP_SEG, NULL
> > > > > > > > > > > > },
> > > > > > > > > > > > { PKT_TX_OUTER_UDP_CKSUM,
> > > > > > > > > > > > PKT_TX_OUTER_UDP_CKSUM, NULL },
> > > > > > > > > > > > + { PKT_TX_MARK_VLAN_DEI,
> > > > > > > > > > > > PKT_TX_MARK_VLAN_DEI, NULL },
> > > > > > > > > > > > + { PKT_TX_MARK_IP_DSCP,
> > > > > > > > > > > > PKT_TX_MARK_IP_DSCP, NULL },
> > > > > > > > > > > > + { PKT_TX_MARK_IP_ECN,
> > > > > > > > > > > > PKT_TX_MARK_IP_ECN, NULL },
> > > > > > > > > > > > };
> > > > > > > > > > > > const char *name;
> > > > > > > > > > > > unsigned int i;
> > > > > > > > > > > > diff --git a/lib/librte_mbuf/rte_mbuf_core.h
> > > > > > > > > > > > b/lib/librte_mbuf/rte_mbuf_core.h
> > > > > > > > > > > > index b9a59c8..d9f1290 100644
> > > > > > > > > > > > --- a/lib/librte_mbuf/rte_mbuf_core.h
> > > > > > > > > > > > +++ b/lib/librte_mbuf/rte_mbuf_core.h
> > > > > > > > > > > > @@ -187,11 +187,40 @@ extern "C" {
> > > > > > > > > > > > /* add new RX flags here, don't forget to update
> > > > > > > > > > > > PKT_FIRST_FREE */
> > > > > > > > > > > >
> > > > > > > > > > > > #define PKT_FIRST_FREE (1ULL << 23)
> > > > > > > > > > > > -#define PKT_LAST_FREE (1ULL << 40)
> > > > > > > > > > > > +#define PKT_LAST_FREE (1ULL << 37)
> > > > > > > > > > > >
> > > > > > > > > > > > /* add new TX flags here, don't forget to update
> > > > > > > > > > > > PKT_LAST_FREE */
> > > > > > > > > > > >
> > > > > > > > > > > > /**
> > > > > > > > > > > > + * Packet marking offload flags. These flags indicated
> > > > > > > > > > > > what kind
> > > > > > > > > > > > + * of packet marking needs to be applied on a given
> > > > > > > > > > > > mbuf when
> > > > > > > > > > > > + * appropriate Traffic Manager configuration is in
> > > > > > > > > > > > place.
> > > > > > > > > > > > + * When user set's these flags on a mbuf, below
> > > > > > > > > > > > assumptions are made
> > > > > > > > > > > > + * 1) When PKT_TX_MARK_VLAN_DEI is set,
> > > > > > > > > > > > + * a) PMD assumes pkt to be a 802.1q packet.
> > > > > > > >
> > > > > > > > What does that imply?
> > > > > > >
> > > > > > > I meant by setting the flag, a packet has VLAN header adhering to
> > > > > > > IEEE 802.1Q spec.
> > > > > > >
> > > > > > > >
> > > > > > > > > > > > + * b) Application should also set mbuf.l2_len where
> > > > > > > > > > > > 802.1Q header is
> > > > > > > > > > > > + * at (mbuf.l2_len - 6) offset.
> > > > > > > >
> > > > > > > > Why mbuf.l2_len - 6 ?
> > > > > > > L2 header when VLAN header is preset will be
> > > > > > > {custom header 'X' Bytes}:{Ethernet SRC+DST (12B)}:{VLAN Header
> > > > > > > (4B)}:{Ether Type (2B)}
> > > > > > > l2_len = X + 12 + 4 + 2
> > > > > > > So, VLAN header starts at (l2_len - 6) bytes.
> > > > > > >
> > > > > > > >
> > > > > > > > > > > > + * 2) When PKT_TX_MARK_IP_DSCP is set,
> > > > > > > > > > > > + * a) Application should also set either PKT_TX_IPV4
> > > > > > > > > > > > or PKT_TX_IPV6
> > > > > > > > > > > > + * to indicate whether if it is IPv4 packet or IPv6
> > > > > > > > > > > > packet
> > > > > > > > > > > > + * for DSCP marking. It should also set
> > > > > > > > > > > > PKT_TX_IP_CKSUM if it is
> > > > > > > > > > > > + * IPv4 pkt.
> > > > > > > > > > > > + * b) Application should also set mbuf.l2_len that
> > > > > > > > > > > > indicates
> > > > > > > > > > > > + * start offset of L3 header.
> > > > > > > > > > > > + * 3) When PKT_TX_MARK_IP_ECN is set,
> > > > > > > > > > > > + * a) Application should also set either PKT_TX_IPV4
> > > > > > > > > > > > or PKT_TX_IPV6.
> > > > > > > > > > > > + * It should also set PKT_TX_IP_CKSUM if it is IPv4
> > > > > > > > > > > > pkt.
> > > > > > > > > > > > + * b) PMD will assume pkt L4 protocol is either TCP or
> > > > > > > > > > > > SCTP and
> > > > > > > > > > > > + * ECN is set to 2'b01 or 2'b10 as per RFC 3168 and
> > > > > > > > > > > > hence HW
> > > > > > > > > > > > + * can mark the packet for a configured color.
> > > > > > > > > > > > + * c) Application should also set mbuf.l2_len that
> > > > > > > > > > > > indicates
> > > > > > > > > > > > + * start offset of L3 header.
> > > > > > > > > > > > + */
> > > > > > > > > > > > +#define PKT_TX_MARK_VLAN_DEI (1ULL << 38)
> > > > > > > > > > > > +#define PKT_TX_MARK_IP_DSCP (1ULL << 39)
> > > > > > > > > > > > +#define PKT_TX_MARK_IP_ECN (1ULL << 40)
> > > > > > > >
> > > > > > > > We should have one comment per define.
> > > > > > > Ack, will fix in V2.
> > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > > > > > +
> > > > > > > > > > > > +/**
> > > > > > > > > > > > * Outer UDP checksum offload flag. This flag is used
> > > > > > > > > > > > for enabling
> > > > > > > > > > > > * outer UDP checksum in PMD. To use outer UDP
> > > > > > > > > > > > checksum, the user needs to
> > > > > > > > > > > > * 1) Enable the following in mbuf,
> > > > > > > > > > > > @@ -384,7 +413,10 @@ extern "C" {
> > > > > > > > > > > > PKT_TX_MACSEC | \
> > > > > > > > > > > > PKT_TX_SEC_OFFLOAD | \
> > > > > > > > > > > > PKT_TX_UDP_SEG | \
> > > > > > > > > > > > - PKT_TX_OUTER_UDP_CKSUM)
> > > > > > > > > > > > + PKT_TX_OUTER_UDP_CKSUM | \
> > > > > > > > > > > > + PKT_TX_MARK_VLAN_DEI | \
> > > > > > > > > > > > + PKT_TX_MARK_IP_DSCP | \
> > > > > > > > > > > > + PKT_TX_MARK_IP_ECN)
> > > > > > > > > > > >
> > > > > > > > > > > > /**
> > > > > > > > > > > > * Mbuf having an external buffer attached. shinfo in
> > > > > > > > > > > > mbuf must be filled.
> > > > > > > > > > > > --
> > > > > > > > > > > > 2.8.4
> > > > > > > > > > > >
