/$$$$$$$$ /$$
|__ $$__/ | $$
| $$ /$$$$$$ /$$$$$$$| $$ /$$$$$$
| $$ /$$__ $$ /$$_____/| $$ |____ $$
| $$| $$$$$$$$| $$$$$$ | $$ /$$$$$$$
| $$| $$_____/ \____ $$| $$ /$$__ $$
| $$| $$$$$$$ /$$$$$$$/| $$| $$$$$$$
|__/ \_______/|_______/ |__/ \_______/
/$$$$$$$$ /$$
|__ $$__/ | $$
| $$ /$$$$$$ /$$$$$$ /$$$$$$$ /$$$$$$$ /$$$$$$ /$$$$$$ /$$$$$$ /$$$$$$
| $$ /$$__ $$|____ $$| $$__ $$ /$$_____/ /$$__ $$ /$$__ $$ /$$__ $$|_ $$_/
| $$| $$ \__/ /$$$$$$$| $$ \ $$| $$$$$$ | $$ \ $$| $$ \ $$| $$ \__/ | $$
| $$| $$ /$$__ $$| $$ | $$ \____ $$| $$ | $$| $$ | $$| $$ | $$ /$$
| $$| $$ | $$$$$$$| $$ | $$ /$$$$$$$/| $$$$$$$/| $$$$$$/| $$ | $$$$/
|__/|__/ \_______/|__/ |__/|_______/ | $$____/ \______/ |__/ \___/
| $$
| $$
|__/
/$$$$$$$ /$$ /$$
| $$__ $$ | $$ | $$
| $$ \ $$ /$$$$$$ /$$$$$$ /$$$$$$ /$$$$$$ /$$$$$$$ /$$$$$$ | $$
| $$$$$$$//$$__ $$ /$$__ $$|_ $$_/ /$$__ $$ /$$_____/ /$$__ $$| $$
| $$____/| $$ \__/| $$ \ $$ | $$ | $$ \ $$| $$ | $$ \ $$| $$
| $$ | $$ | $$ | $$ | $$ /$$| $$ | $$| $$ | $$ | $$| $$
| $$ | $$ | $$$$$$/ | $$$$/| $$$$$$/| $$$$$$$| $$$$$$/| $$
|__/ |__/ \______/ \___/ \______/ \_______/ \______/ |__/
At HotChips 2024, Tesla announced the open-sourcing of the Tesla Transport Protocol over Ethernet (TTPoE), represented on this GitHub repo.
Tesla also announced joining the Ultra Ethernet Consortium (UEC) to share this protocol and work to standardize a new high-speed/low-latency fabric (be that TTPoE or otherwise) for AI/ML/Datacenters -- desiring a non-proprietary, low cost, distributed congestion control, standard EthernetII frame, and non-centralized interconnect protocol to commoditize and accelerate technical progress.
In TTPoE, just like TCP, dropped packets and replays are the acceptable default behavior, yet full transmission is guaranteed.
TTPoE's initial deployment was for the Tesla Dojo v1 project, where the protocol executed entirely in hardware and deployed to a very large multi-ExaFlops (fp16) supercomputer with over 10s of thousands of concurrent endpoints. This protocol does not need a CPU or OS to be involved in any way to link and execute.
If you came here to be impressed by something complex and clever, you won't be. The protocol is designed on basic fundamentals -- simple transport and to the point. Ethernet transport in essence is only intended to move data from point A to B and should be limited by physics -- not software execution time. Centralized congestion management of extremely large scale machines (just like the internet) is a fool's errand -- each endpoint should be resiliant and self-managing.
Eric Quinnell -- Sept 13, 2024
/* Transport Header (TTP) that follows TSH
*
* 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
* | opcode [7:0] | vc [7:0] |
* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
* | tx [7:0] | rx [7:0] |
* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
* | epoch [15:0] |
* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
* | congestion [7:0] | reserved-byte [7:0] |
* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
* | reserved-byte [7:0] | extension [7:0] |
* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
* | tx-sequence [31:0] |
* | |
* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
* | rx-sequence [31:0] |
* | |
* +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
*/
You will find the spec
In the repo "doc" folder
TTPoE
The following sections have details regarding making and executing the reference linux kernel sw model. It is matched to v1.5 of the TTP specification. Some variables may have changed slightly without documentation updates, but we're sure you can figure it out.
GIT repo info and unit tests
The source code git repo is at https://github.com/teslamotors/ttpoe. The code for modttpoe is under the 'modttpoe' subdir. The compilation is controlled via a top level Makefile in order to allow related modules to share symbols. Compilation is done as follows (gcc, linux-5.15-0-48-generic, ubuntu22):
$ pwd
GIT_HEAD
$ make all
.... <compilation output> ....
$ ls -l ./modttpoe/modttpoe.ko
-rw-rw-r-- 1 user group 3456000 Jan 1 10:00 modttpoe/modttpoe.ko
$ modinfo ./modttpoe/modttpoe.ko
filename: /home/dojo-user/work/git/tesla/ttpoe_sw/modttpoe/modttpoe.ko
license: GPL
version: 1.0
description: TTP Over Ethernet
author: dntundlam@tesla.com
srcversion: 547796AAC2C633E730FAF4F
depends:
retpoline: Y
name: modttpoe
vermagic: 6.11.0-9-generic SMP preempt mod_unload modversions
parm: dev: ttp device name (required at module-load)
parm: dest_mac: ttp destination mac-address: e.g. dest_mac=xx:xx:xx:xx:xx:xx)
parm: valid: target is valid (default=0, or 1)
parm: vci: ttp conn-VCI (default=0, 1, 2)
parm: use_gw: use gateway to reach target (default=0, or 1)
parm: nhmac: next-hop mac address (format: xx:xx:xx:xx:xx:xx)
parm: ipv4: encap mode for TTP: 0 = TTPoE, 1 = TTPoIPv4 (read-only)
parm: prefix: ipv4 prefix: (A.B.C.D/N)
parm: ipv4_sip: ipv4 src-ip: (A.B.C.D)
parm: ipv4_dip: ipv4 dst-ip: (A.B.C.D)
parm: verbose: kernel log verbosity level (default=(-1), 0, 1, 2, 3)
parm: drop_pct: packet drop percent (default=(0), [0:10])
parm: shutdown: modttpoe shutdown state
parm: stats: ttp counters (read-only)
parm: target: ttp debug target (24b hex value: e.g. target=012345 => [oui]:01:23:45)
parm: tag_seq: starting value of tag seq number (default=1)
parm: wkstep: ttp fsm single-step state (default=0)
write '0' run freely; '[1-100]' set step-size; 's' step
The repo includes a script with unit tests under the 'tests' directory, using the python unit_test framework. These tests use the 'noc_debug' interface to configure and test a set of basic functionality to serve as a suite of regression tests to run before making any changes to the source code, and when adding enhancements. It is recommended to enhance the tests when new features are added to 'modttpoe'. In additional a packet generation utility called 'trafgen' (which is part of the http://netsniff-ng.org/ tooklit) it used to some inject custom TTP packets to validate the behavior of the TTP state machine functionality.
Here is an example TTP session between two hosts: node-01 and node-02:
node-01:
$ sudo insmod modttpoe.ko dev=veth verbose=2
$ sudo dmesg -tw
ttpoe_init: ttp-source:00:00:00:00:00:01 mytag:[0x0000000100000001]
dev:veth nhmac:98:ed:5c:ff:ff:ff ipv4:0
-------------------- Module modttpoe.ko loaded --------------------+
$ echo 2 > /sys/module/modttpoe/parameters/target
$ cat /proc/net/modttpoe/tags
Tag V B VC ST Q X Y mac-addr gw rx-seq tx-seq ret-id #op/nl ------ kid -------
2 1 0 0 OS 0 0 0 00:00:02 0 1 2 1 29 0x0000000200000002
node-02:
$ sudo insmod modttpoe.ko dev=veth verbose=2
$ sudo dmesg -tw
ttpoe_init: ttp-source:98:ed:5c:00:00:02 mytag:[0x0000000200000002]
dev:veth nhmac:98:ed:5c:ff:ff:ff ipv4:0
-------------------- Module modttpoe.ko loaded --------------------+
...
$ cat /proc/net/modttpoe/tags
Tag V B VC ST Q X Y mac-addr gw rx-seq tx-seq ret-id #op/nl ------ kid -------
1 1 0 0 OP 0 0 0 00:00:01 0 1 2 1 0 0x0000000100000001
$ cat /proc/net/modttpoe/ev_log
6 off file:line age vc tag B state/action event-name opcode-name response dir len rx-seq tx-seq next-state next-sef kid.idx
0 5 modttpoe/fsm.c:116 0 - - - L_^## TTP_LINK_UP __int_/_none__ - ..^ 0 1 0 - - 0x0000000100000001.1 0
1 4 modttpoe/fsm.c:325 0 - - - <<<<< NETWORK_PKT_TX TTP_OPEN_ACK - <tx 0 1 -1 - - 0x0000000100000001.1 0
2 3 modttpoe/tags.c:703 0 0 1 0 OPEN_RECD int__ALLOC_TAG TTP_OPEN_ACK OPEN_ACK 0 1 -1 OPEN CHECK_NOC 0x0000000100000001.1 0
3 2 modttpoe/tags.c:703 0 0 0 0 CLOSED RXQ__TTP_OPEN __int_/_none__ __none__ 0 1 1 OPEN_RECD TAG_ALLOC 0x0000000100000001.0 0
4 1 modttpoe/ttpoe.c:435 0 - - - >>>>> NETWORK_PKT_RX TTP_OPEN - >rx 0 1 1 - - 0x0000000100000001.0 0
5 0 modttpoe/ttpoe.c:781 5341 - - - __up- TTP_INIT __int_/_none__ - .'. 0 -1 -1 - - 0x0000000000000000.0 0
node-01:
$ cat /proc/net/modttpoe/ev_log
8 off file:line age vc tag B state/action event-name opcode-name response dir len rx-seq tx-seq next-state next-sef kid.idx
0 7 modttpoe/fsm.c:116 0 - - - L_^## TTP_LINK_UP __int_/_none__ - ..^ 0 1 0 - - 0x0000000200000002.1 0
1 6 modttpoe/fsm.c:745 0 - - - !x___ TIMER_DELETE TTP_OPEN_ACK - x! 0 1 -1 - - 0x0000000200000002.1 0
2 5 modttpoe/tags.c:703 0 0 2 0 OPEN_SENT RXQ__TTP_OPEN_ACK __int_/_none__ __none__ 0 1 0 OPEN CHECK_NOC 0x0000000200000002.1 0
3 4 modttpoe/ttpoe.c:435 0 - - - >>>>> NETWORK_PKT_RX TTP_OPEN_ACK - >rx 0 1 -1 - - 0x0000000200000002.1 0
4 3 modttpoe/fsm.c:143 0 - - - !S_-_ SHORT_TMR_START __int_/_none__ - _! 0 1 1 - - 0x0000000200000002.0 0
5 2 modttpoe/fsm.c:360 0 - - - <<<<< NETWORK_PKT_TX TTP_OPEN - <tx 0 1 1 - - 0x0000000200000002.0 0
6 1 modttpoe/tags.c:703 0 0 2 0 CLOSED TXQ__TTP_OPEN TTP_OPEN OPEN 0 0 0 OPEN_SENT OPEN_TIMER 0x0000000200000002.0 0
7 0 modttpoe/ttpoe.c:781 37878 - - - __up- TTP_INIT __int_/_none__ - .'. 0 -1 -1 - - 0x0000000000000000.0 0
$ echo 'Hello Tesla' > /dev/noc_debug
$ cat /proc/net/modttpoe/tags
Tag V B VC ST Q X Y mac-addr gw rx-seq tx-seq ret-id #op/nl ------ kid -------
2 1 0 0 OP 0 0 0 00:00:02 0 1 3 2 248 0x0000000200000002
$ cat /proc/net/modttpoe/ev_log
17 off file:line age vc tag B state/action event-name opcode-name response dir len rx-seq tx-seq next-state next-sef kid.idx
0 16 modttpoe/fsm.c:789 0 - - - -free NOC_PAYLOAD_FREE TTP_ACK - -fr 0 0 -1 - - 0x0000000200000002.2 1
1 15 modttpoe/fsm.c:767 0 - - - !x___ TIMER_DELETE TTP_ACK - x! 0 2 -1 - - 0x0000000200000002.4 0
2 14 modttpoe/tags.c:703 0 0 2 0 OPEN RXQ__TTP_ACK __int_/_none__ __none__ 0 2 0 __stay__ __none__ 0x0000000200000002.4 0
3 13 modttpoe/ttpoe.c:435 0 - - - >>>>> NETWORK_PKT_RX TTP_ACK - >rx 0 2 -1 - - 0x0000000200000002.4 0
4 12 modttpoe/fsm.c:611 0 - - - !L_-_ LONG_TMR_START __int_/_none__ - !! 0 0 2 - - 0x0000000200000002.3 0
5 11 modttpoe/fsm.c:601 0 - - - <<<<< NETWORK_PKT_TX TTP_PAYLOAD - <tx 12 0 2 - - 0x0000000200000002.3 0
6 10 modttpoe/tags.c:703 0 0 2 0 OPEN TXQ__TTP_PAYLOAD TTP_PAYLOAD PAYLOAD 12 0 2 __stay__ __none__ 0x0000000200000002.3 2
7 9 modttpoe/tags.c:1056 0 - - - <<-vv NOC_PAYLOAD_ENQ TTP_PAYLOAD - -vv 12 0 2 - - 0x0000000200000002.2 1
8 8 modttpoe/noc.c:256 0 - - - vvvvv NOC_PAYLOAD_TX TTP_PAYLOAD - -tx 12 0 0 - - 0x0000000200000002.2 1
9 7 modttpoe/fsm.c:116 188553 - - - L_^## TTP_LINK_UP __int_/_none__ - ..^ 0 1 0 - - 0x0000000200000002.1 0
10 6 modttpoe/fsm.c:745 0 - - - !x___ TIMER_DELETE TTP_OPEN_ACK - x! 0 1 -1 - - 0x0000000200000002.1 0
11 5 modttpoe/tags.c:703 0 0 2 0 OPEN_SENT RXQ__TTP_OPEN_ACK __int_/_none__ __none__ 0 1 0 OPEN CHECK_NOC 0x0000000200000002.1 0
12 4 modttpoe/ttpoe.c:435 0 - - - >>>>> NETWORK_PKT_RX TTP_OPEN_ACK - >rx 0 1 -1 - - 0x0000000200000002.1 0
13 3 modttpoe/fsm.c:143 0 - - - !S_-_ SHORT_TMR_START __int_/_none__ - _! 0 1 1 - - 0x0000000200000002.0 0
14 2 modttpoe/fsm.c:360 0 - - - <<<<< NETWORK_PKT_TX TTP_OPEN - <tx 0 1 1 - - 0x0000000200000002.0 0
15 1 modttpoe/tags.c:703 0 0 2 0 CLOSED TXQ__TTP_OPEN TTP_OPEN OPEN 0 0 0 OPEN_SENT OPEN_TIMER 0x0000000200000002.0 0
16 0 modttpoe/ttpoe.c:781 37878 - - - __up- TTP_INIT __int_/_none__ - .'. 0 -1 -1 - - 0x0000000000000000.0 0
node-02:
$ cat /proc/net/modttpoe/tags
Tag V B VC ST Q X Y mac-addr gw rx-seq tx-seq ret-id #op/nl ------ kid -------
1 1 0 0 OP 0 0 0 00:00:01 0 2 2 1 0 0x0000000100000001
$ cat /dev/noc_debug
Hello Tesla
$ cat /proc/net/modttpoe/ev_log
10 off file:line age vc tag B state/action event-name opcode-name response dir len rx-seq tx-seq next-state next-sef kid.idx
0 9 modttpoe/fsm.c:544 0 - - - <<<<< NETWORK_PKT_TX TTP_ACK - <tx 0 2 -1 - - 0x0000000100000001.2 0
1 8 modttpoe/fsm.c:500 0 - - - ^^^^^ NOC_PAYLOAD_RX TTP_ACK - -rx 0 0 -1 - - 0x0000000100000001.2 0
2 7 modttpoe/tags.c:703 0 0 1 0 OPEN RXQ__TTP_PAYLOAD TTP_ACK ACK 0 0 -1 __stay__ __none__ 0x0000000100000001.2 0
3 6 modttpoe/ttpoe.c:435 0 - - - >>>>> NETWORK_PKT_RX TTP_PAYLOAD - >rx 12 0 2 - - 0x0000000100000001.2 0
4 5 modttpoe/fsm.c:116 188552 - - - L_^## TTP_LINK_UP __int_/_none__ - ..^ 0 1 0 - - 0x0000000100000001.1 0
5 4 modttpoe/fsm.c:325 0 - - - <<<<< NETWORK_PKT_TX TTP_OPEN_ACK - <tx 0 1 -1 - - 0x0000000100000001.1 0
6 3 modttpoe/tags.c:703 0 0 1 0 OPEN_RECD int__ALLOC_TAG TTP_OPEN_ACK OPEN_ACK 0 1 -1 OPEN CHECK_NOC 0x0000000100000001.1 0
7 2 modttpoe/tags.c:703 0 0 0 0 CLOSED RXQ__TTP_OPEN __int_/_none__ __none__ 0 1 1 OPEN_RECD TAG_ALLOC 0x0000000100000001.0 0
8 1 modttpoe/ttpoe.c:435 0 - - - >>>>> NETWORK_PKT_RX TTP_OPEN - >rx 0 1 1 - - 0x0000000100000001.0 0
9 0 modttpoe/ttpoe.c:781 5341 - - - __up- TTP_INIT __int_/_none__ - .'. 0 -1 -1 - - 0x0000000000000000.0 0
$ ./tests/run.sh --target=2 -v
v---------------------------------------v
Start tests: 2024-10-10 10:00:00.000000
TTP Encap: ttpoe (etype: 0x9ac6)
Self MAC: 98:ed:5c:00:00:01
Self Target: 000001
Self Host: node-01
Peer MAC: 98:ed:5c:00:00:02
Peer Target: 000002
Peer Host: node-02
Use Gateway: False
test1_seq_clr (__main__.Test0_Seq_IDs.test1_seq_clr) ... ok
test2_tx1_seq (__main__.Test0_Seq_IDs.test2_tx1_seq) ... ok
test3_rx1_seq (__main__.Test0_Seq_IDs.test3_rx1_seq) ... ok
test4_tx2_seq (__main__.Test0_Seq_IDs.test4_tx2_seq) ... ok
test1_proc_stats (__main__.Test1_Proc.test1_proc_stats) ... ok
test2_ttpoe_tags (__main__.Test1_Proc.test2_ttpoe_tags) ... ok
test3_debug__500 (__main__.Test1_Proc.test3_debug__500) ... ok
test4_debug_1000 (__main__.Test1_Proc.test4_debug_1000) ... ok
test5_debug_2000 (__main__.Test1_Proc.test5_debug_2000) ... ok
test6_debug_3000 (__main__.Test1_Proc.test6_debug_3000) ... ok
test7_debug_4000 (__main__.Test1_Proc.test7_debug_4000) ... ok
test1_get_open (__main__.Test2_Packet.test1_get_open) ... ok
test2_snd_open (__main__.Test2_Packet.test2_snd_open) ... ok
test3_get_pyld (__main__.Test2_Packet.test3_get_pyld) ... ok
test4_snd_pyld (__main__.Test2_Packet.test4_snd_pyld) ... ok
test5_get_clos (__main__.Test2_Packet.test5_get_clos) ... ok
test6_snd_clos (__main__.Test2_Packet.test6_snd_clos) ... ok
test1_show_tag (__main__.Test3_Noc_db.test1_show_tag) ... ok
test2_show_dbg (__main__.Test3_Noc_db.test2_show_dbg) ... ok
test1_traffic (__main__.Test4_Traffic.test1_traffic) ... ok
test2_traffic (__main__.Test4_Traffic.test2_traffic) ... ok
test3_traffic (__main__.Test4_Traffic.test3_traffic) ... ok
test4_traffic (__main__.Test4_Traffic.test4_traffic) ... ok
test5_traffic (__main__.Test4_Traffic.test5_traffic) ... ok
test1_cleanup (__main__.Test5_Cleanup.test1_cleanup) ... ok
test2_cleanup (__main__.Test5_Cleanup.test2_cleanup) ... ok
test3_cleanup (__main__.Test5_Cleanup.test3_cleanup) ... ok
----------------------------------------------------------------------
Ran 27 tests in 14.301s
OK
Currently there are no unit-tests for the TTP gateway. The module 'modttpip' has configuration parameters, some of which must be specified on the command line during insmod:
$ modinfo modttpip/modttpip.ko
filename: /home/dojo-user/work/git/tesla/ttpoe_sw/modttpip/modttpip.ko
license: GPL
version: 1.0
description: TTP IP Gateway
author: dntundlam@tesla.com
srcversion: FCBBF59CD1A10DCE72F2936
depends:
retpoline: Y
name: modttpip
vermagic: 6.11.0-9-generic SMP preempt mod_unload modversions
parm: gwips: set list of ttp gateway ip-addreses per zone (1,2,3,..):
e.g. gwips=10.0.1.1,10.0.2.2,10.0.3.3,..
parm: intfs: get all interfaces on the ttp-gateway
parm: edevs: get all devices on the ttp-gateway
parm: dev: ttp device name (required at module-load)
parm: mactbl: read gateway mac-address table
parm: drop_pct: packet drop percent (default=(0), [0:10])
parm: shutdown: modttpoe shutdown state
parm: verbose: kernel log verbosity level (default=(-1), 0, 1, 2, 3)
$ sudo insmod modttpip.ko dev=veth gwips=192.168.80.10,192.168.80.20,192.168.30.30 verbose=1
$ sudo dmesg -tw
ttp_param_gwips_set: Parsing gwips from '192.168.80.10,192.168.80.20,192.168.30.30'
`->: Zeroed out 64 bytes: 8 ttp_zones
`->zn:1 ip4:192.168.80.10
`->zn:2 ip4:192.168.80.20
`->zn:3 ip4:192.168.30.30
ttp_param_gwips_set: Scanning network devices:
`->Found device: dev:ens20 id:4 mac:bc:24:11:b8:94:64
`->Scanning ipv4 addresses: on dev:ens20
`->ipv4:192.168.80.10/24
`->Found zone: my_zn:1 dev:ens20 ip4:192.168.80.10/24
ttpip_init: ip4-if:'ens20' mac:bc:24:11:b8:94:64
ttp-if:'vleth' mac:bc:24:11:23:48:45
------------------ Module modttpip.ko loaded -----------------+
`->zn:2 gw:192.168.80.20 -> mac:bc:24:11:f8:e6:de
`->via:dir-arp:192.168.80.20 -> dev:ens20
`->zn:3 gw:192.168.30.30 -> mac:fa:df:59:d6:41:8d
`->via:rt-v4:192.168.80.1 -> dev:ens20
ttp_nh_mac_tmr_cb: resolved all nh-macs
$ ls -l /sys/module/modttpip/parameters
-r--r--r-- 1 root root 4096 Nov 13 15:58 dev
-rw-r--r-- 1 root root 4096 Nov 13 15:58 drop_pct
-r--r--r-- 1 root root 4096 Nov 13 15:58 edevs
-rw-r--r-- 1 root root 4096 Nov 13 15:58 gwips
-r--r--r-- 1 root root 4096 Nov 13 15:58 intfs
-r--r--r-- 1 root root 4096 Nov 13 15:53 mactbl
-rw-r--r-- 1 root root 4096 Nov 13 15:58 shutdown
-rw-r--r-- 1 root root 4096 Nov 13 15:58 verbose
There are no runtime configurable parameters in modttpip. Unloading modttpip is done as follows:
$ sudo rmmod modttpip
$ sudo dmesg -tw
ttpip: ~~~~~~~~~~~~~~~~~~~~~ Module modttpip.ko unloaded ~~~~~~~~~~~~~~~~~~~~~+
