Hi lads, > -----Original Message----- > From: Liu, Jijiang > Sent: Wednesday, January 14, 2015 3:01 AM > To: Olivier MATZ > Cc: dev at dpdk.org; Ananyev, Konstantin > Subject: RE: [dpdk-dev] [PATCH v3 0/3] enhance TX checksum command and csum > forwarding engine > > Hi Olivier, > > > -----Original Message----- > > From: Olivier MATZ [mailto:olivier.matz at 6wind.com] > > Sent: Tuesday, January 13, 2015 5:56 PM > > To: Liu, Jijiang > > Cc: dev at dpdk.org; Ananyev, Konstantin > > Subject: Re: [dpdk-dev] [PATCH v3 0/3] enhance TX checksum command and > > csum forwarding engine > > > > Hi Jijiang, > > > > On 01/13/2015 04:04 AM, Liu, Jijiang wrote: > > > the following two commands are. > > > > > > 1. tx_checksum set sw-tunnel-mode on/off > > > > > > 2. tx_checksum set hw-tunnel-mode on/off > > > > > > For command 1, If the sw-tunnel-mode is set/clear, which will > > > set/clear a testpmd flag that is used in the process of analyzing > > > incoming packet., the pseudo-codes are list below, > > > > > > If (sw-tunnel-mode) > > > > > > Csum fwd engine will analyze if incoming packet is a tunneling packet. > > > tunnel = 1; > > > else > > > Csum fwd engine will not analyze if incoming packet is a > > > tunneling > > packet, and treat all the incoming packets as non-tunneling packets. > > > It is used for A. > > > > What about "recognize-tunnel" instead of "sw-tunnel-mode"? > > Or "parse-tunnel"? > > Ok, "parse-tunnel" or "parse-tunnel-pkt" is better. > Thanks. > > > > To me, using "sw-" or "hw-" prefix is confusing because in any case the > > checksums > > can be calculated in software or hardware depending on "tx_checksum set > > outer- > > ip hw|sw". > > > > Moreover, this command has an impact on receive side, but the name is still > > "tx_checksum". Maybe this is also confusing. > Ok, how about this? > > set checksum parse-tunnel-pkt on|off (port-id) > > > > For command 2, If the hw-tunnel-mode is set/clear, which will > > > set/clear a testpmd flag that is used in the process of how to handle > > > tunneling packet, the pseudo-codes are list below, > > > > > > if (tunnel == 1) { // this is a tunneling packet > > > If (hw-tunnel-mode) > > > ol_flags |= PKT_TX_UDP_TUNNEL_PKT; > > > > > > Csum fwd engine set PKT_TX_UDP_TUNNEL_PKT offload flag, which > > means to tell HW treat the transmit packet as a tunneling packet to do > > checksum > > offload. > > > It is used for B.1 > > > Else > > > Csum fwd engine doesn't set PKT_TX_UDP_TUNNEL_PKT > > > offload > > flag, which means tell HW to treat the packet as ordinary (non-tunnelled) > > packet. > > > It is used for B.2 > > > } > > > > What about: > > tx_checksum set tunnel-method normal|outer > > It would select if we use lX_len or outer_lX_len. Is it what you mean? > > tx_checksum set tunnel-method normal|outer > > Let me explain that what differences of TX checksum mechanism between > ixgbe(82599) and i40e(40G NIC) are. > > For 82599, there is only one register that is used for L3 checksum offload. > So for tunneling packet, hardware is unable to recognize the > packet is tunneling packet and the register cannot be worked for both outer > L3 checksum offload and inner L3 checksum offload at the > same time, just for outer or inner. > > For i40e(40G NIC), there are two registers that are user for L3 TX checksum > offload, so for tunneling packet, the outer and inner L3 > checksum offload can be done by hardware at the same time, but a > prerequisite is that we must tell > Hardware the packet is a tunneling packet by setting a register > (PKT_TX_UDP_TUNNEL_PKT offload flag is used to indicate to set this > register.) > > As for other NIC, I think its working mechanism should be same as the i40e if > it can recognize tunneling packet. > > So my idea: > tx_checksum set tunnel-method tunnel-pkt on|off > > or > tx_checksum set tunnel-pkt on|off > > What do you think? > > > > And this only makes sense when we use hw checksum right? > yes > > > > > >> And will it be possible to support future hardware that will be able > > >> to compute both outer l3, outer l4, l3 and l4 checksums? > > Currently, if outer l4 will be supported in the future, and we can add > outer-udp/tcp option into following command. > Tx_checksum set outer-ip|ip|sctp|udp|tcp. > > > > > Yes. > > > Currently, i40e support outer l3, outer l4, l3 and l4 checksums offload > > > at the > > same time. > Sorry, my bad. > I40e just support outer l3, l3 and l4. > > Fortville can offload the following L3 and L4 integrity checks: IPv4 > header(s) checksum for "simple" and tunneled packets, Inner TCP or > UDP checksum and SCTP CRC integrity. Tunneling UDP headers and GRE header are > not offloaded while Fortville leaves their checksum > field as is. If a checksum is required, software should provide it as well as > the inner checksum value(s) that are required for the outer > checksum. > > > > > >> I have another idea, please let me know if you find it clearer or not. > > >> The commands format would be: > > >> > > >> tx_checksum <pkt-type> <field1> <action1> <field2> <action2> ... > > >> > > >> [...] > > >> > > >> What do you think? > > > > > > Thanks for your proposal. > > > It is clear for me. > > > > > > But there are two questions for me. > > > > > > As I know, in current command line framework, the option in command line > > > is > > exact match, so you probably have to add duplicated codes when you want to > > support a new packet types. > > > > I don't think it's really a problem. The cmdline library supports string > > list, so can > > have the following 3 commands definitions: > > > > 1. tx_checksum > > ip-udp|ip-tcp|ip-sctp|vxlan-ip-udp|vxlan-ip-tcp|vxlan-ip-sctp l3 > > off|sw|hw l4 off|sw|hw > > 2. tx_checksum ip-other|vxlan-ip-other l3 off|sw|hw 3. tx_checksum vxlan > > outer-l3 off|sw|hw outer-l4 off|sw|hw > > > > Maybe 1 and 2 could be splitted in non-vxlan and vxlan. But only the > > structure > > should be redefined to have a different help string, not the callback > > function. > > > Ok, but I think you probably need to add many string in the list :) > > > > Other question: > > > > > > Currently, the following testpmd flag is for per port, not for per packet > > > type, > > when they are set, which will affect whole port, not just for packet type > > or format, > > if you add <pkt-type> option in cmdline, which means you have to other > > changes. > > > > > > /** Offload IP checksum in csum forward engine */ > > > #define TESTPMD_TX_OFFLOAD_IP_CKSUM 0x0001 > > > /** Offload UDP checksum in csum forward engine */ > > > #define TESTPMD_TX_OFFLOAD_UDP_CKSUM 0x0002 > > > /** Offload TCP checksum in csum forward engine */ > > > #define TESTPMD_TX_OFFLOAD_TCP_CKSUM 0x0004 > > > /** Offload SCTP checksum in csum forward engine */ > > > #define TESTPMD_TX_OFFLOAD_SCTP_CKSUM 0x0008 > > > /** Offload VxLAN checksum in csum forward engine */ > > > #define TESTPMD_TX_OFFLOAD_VXLAN_CKSUM 0x0010 > > > > We can add a portid in each command. > > Ok, but I think your idea will make the csum fwd engine more complicated. > > > > Of course, it is welcome if you can send this patch set with this idea for > > community review. > > Let's first agree on the user API :) > > If you don't have more comments and questions on my current solution, I will > send new patch set. > Or you can send your patch. > Anyway, our goal is the same.
To be honest, there are so many mails around that subject, so I am already lost :) Oliver, as I understand you are not happy with the test-pmd commands Frank is proposing. Both syntax and semantics. Is that correct? If so, could you suggest something from your side? That would allow to configure test-pmd to behave in any of 4 possible ways we discussed previously: http://dpdk.org/ml/archives/dev/2014-December/009213.html Thanks Konstantin > > > > > Regards, > > Olivier > > > >
