Hi guys > -----Original Message----- > From: Liu, Jijiang > Sent: Friday, January 23, 2015 4:06 PM > To: Olivier Matz; Zhang, Helin > Cc: Ananyev, Konstantin; dev at dpdk.org > Subject: RE: [RFC 04/16] i40e: remove the use of PKT_TX_UDP_TUNNEL_PKT > flag > > Hi, > > > -----Original Message----- > > From: Olivier Matz [mailto:olivier.matz at 6wind.com] > > Sent: Thursday, January 22, 2015 7:36 AM > > To: dev at dpdk.org > > Cc: olivier.matz at 6wind.com; Ananyev, Konstantin; Liu, Jijiang > > Subject: [RFC 04/16] i40e: remove the use of PKT_TX_UDP_TUNNEL_PKT > > flag > > > > The definition of the flag in rte_mbuf.h was: > > TX packet is an UDP tunneled packet. It must be specified when using > > outer checksum offload (PKT_TX_OUTER_IP_CKSUM) > > > > This flag was used to tell the NIC that the offload type is UDP > > (I40E_TXD_CTX_UDP_TUNNELING flag). In the datasheet, it says it's > > required to specify the tunnel type in the register. However, some > > tests (see [1]) showed that it also works without this flag. > > > > Moreover, it is not explained how the hardware use this information. > > From a network perspective, this information is useless for > > calculating the outer IP checksum as it does not depend on the payload. > > > > Having this flag in the API would force the application to specify the > > tunnel type for something that looks only useful for this PMD. It will > > limit the number of possible tunnel types (we would need a flag for > > each tunnel type) and therefore prevent to support outer IP checksum for > proprietary tunnels. > > > > Finally, if a hardware advertises "I support outer IP checksum", it > > must be supported for any payload types. > > > > [1] http://dpdk.org/ml/archives/dev/2015-January/011380.html > > > > Signed-off-by: Olivier Matz <olivier.matz at 6wind.com> > > --- > > lib/librte_pmd_i40e/i40e_rxtx.c | 6 ++---- > > 1 file changed, 2 insertions(+), 4 deletions(-) > > > > diff --git a/lib/librte_pmd_i40e/i40e_rxtx.c > > b/lib/librte_pmd_i40e/i40e_rxtx.c index 9acdeee..0786255 100644 > > --- a/lib/librte_pmd_i40e/i40e_rxtx.c > > +++ b/lib/librte_pmd_i40e/i40e_rxtx.c > > @@ -482,7 +482,7 @@ i40e_txd_enable_checksum(uint64_t ol_flags, > > } > > > > /* UDP tunneling packet TX checksum offload */ > > - if (unlikely(ol_flags & PKT_TX_UDP_TUNNEL_PKT)) { > > + if (unlikely(ol_flags & PKT_TX_OUTER_IP_CKSUM)) { > > This way will disable FVL TX checksum offload capability of inner IP and > inner > L4 using B.1 method. > > Again, the B.1 in > http://dpdk.org/ml/archives/dev/2014-December/009213.html should be > supported and allowed. > > Helin, you are i40e maintainer, what's your point?
Can we list all the possible checksum cases (with or without hardware offloads)? 1. Outer IP (hw csum) + inner IP (hw csum) + L4 (hw csum) 2. Outer IP (hw csum) + inner IP (hw csum) + L4 (sw csum) 3. Outer IP (hw csum) + inner IP (sw csum) + L4 (hw csum) 4. Outer IP (hw csum) + inner IP (sw csum) + L4 (sw csum) 5. Outer IP (sw csum) + inner IP (hw csum) + L4 (hw csum) 6. Outer IP (sw csum) + inner IP (hw csum) + L4 (sw csum) 7. Outer IP (sw csum) + inner IP (sw csum) + L4 (hw csum) 8. Outer IP (sw csum) + inner IP (sw csum) + L4 (sw csum) Does any hardware support all of these cases? If yes, I think we should to have a solution to support all of them. > > > > *td_offset |= (outer_l2_len >> 1) > > << I40E_TX_DESC_LENGTH_MACLEN_SHIFT; @@ -497,7 > +497,6 @@ > > i40e_txd_enable_checksum(uint64_t ol_flags, > > /* Now set the ctx descriptor fields */ > > *cd_tunneling |= (outer_l3_len >> 2) << > > I40E_TXD_CTX_QW0_EXT_IPLEN_SHIFT | > > - I40E_TXD_CTX_UDP_TUNNELING | > > (l2_len >> 1) << > > I40E_TXD_CTX_QW0_NATLEN_SHIFT; > > > > > > > @@ -1165,8 +1164,7 @@ i40e_calc_context_desc(uint64_t flags) { > > uint64_t mask = 0ULL; > > > > - if (flags | PKT_TX_UDP_TUNNEL_PKT) > > - mask |= PKT_TX_UDP_TUNNEL_PKT; > > + mask |= PKT_TX_OUTER_IP_CKSUM; > > > > #ifdef RTE_LIBRTE_IEEE1588 > > mask |= PKT_TX_IEEE1588_TMST; > > -- > > 2.1.3