fbnic.rst

  1.. SPDX-License-Identifier: GPL-2.0+
  2
  3=====================================
  4Meta Platforms Host Network Interface
  5=====================================
  6
  7Firmware Versions
  8-----------------
  9
 10fbnic has three components stored on the flash which are provided in one PLDM
 11image:
 12
 131. fw - The control firmware used to view and modify firmware settings, request
 14   firmware actions, and retrieve firmware counters outside of the data path.
 15   This is the firmware which fbnic_fw.c interacts with.
 162. bootloader - The firmware which validate firmware security and control basic
 17   operations including loading and updating the firmware. This is also known
 18   as the cmrt firmware.
 193. undi - This is the UEFI driver which is based on the Linux driver.
 20
 21fbnic stores two copies of these three components on flash. This allows fbnic
 22to fall back to an older version of firmware automatically in case firmware
 23fails to boot. Version information for both is provided as running and stored.
 24The undi is only provided in stored as it is not actively running once the Linux
 25driver takes over.
 26
 27devlink dev info provides version information for all three components. In
 28addition to the version the hg commit hash of the build is included as a
 29separate entry.
 30
 31Configuration
 32-------------
 33
 34Ringparams (ethtool -g / -G)
 35~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 36
 37fbnic has two submission (host -> device) rings for every completion
 38(device -> host) ring. The three ring objects together form a single
 39"queue" as used by higher layer software (a Rx, or a Tx queue).
 40
 41For Rx the two submission rings are used to pass empty pages to the NIC.
 42Ring 0 is the Header Page Queue (HPQ), NIC will use its pages to place
 43L2-L4 headers (or full frames if frame is not header-data split).
 44Ring 1 is the Payload Page Queue (PPQ) and used for packet payloads.
 45The completion ring is used to receive packet notifications / metadata.
 46ethtool ``rx`` ringparam maps to the size of the completion ring,
 47``rx-mini`` to the HPQ, and ``rx-jumbo`` to the PPQ.
 48
 49For Tx both submission rings can be used to submit packets, the completion
 50ring carries notifications for both. fbnic uses one of the submission
 51rings for normal traffic from the stack and the second one for XDP frames.
 52ethtool ``tx`` ringparam controls both the size of the submission rings
 53and the completion ring.
 54
 55Every single entry on the HPQ and PPQ (``rx-mini``, ``rx-jumbo``)
 56corresponds to 4kB of allocated memory, while entries on the remaining
 57rings are in units of descriptors (8B). The ideal ratio of submission
 58and completion ring sizes will depend on the workload, as for small packets
 59multiple packets will fit into a single page.
 60
 61Upgrading Firmware
 62------------------
 63
 64fbnic supports updating firmware using signed PLDM images with devlink dev
 65flash. PLDM images are written into the flash. Flashing does not interrupt
 66the operation of the device.
 67
 68On host boot the latest UEFI driver is always used, no explicit activation
 69is required. Firmware activation is required to run new control firmware. cmrt
 70firmware can only be activated by power cycling the NIC.
 71
 72Health reporters
 73----------------
 74
 75fw reporter
 76~~~~~~~~~~~
 77
 78The ``fw`` health reporter tracks FW crashes. Dumping the reporter will
 79show the core dump of the most recent FW crash, and if no FW crash has
 80happened since power cycle - a snapshot of the FW memory. Diagnose callback
 81shows FW uptime based on the most recently received heartbeat message
 82(the crashes are detected by checking if uptime goes down).
 83
 84otp reporter
 85~~~~~~~~~~~~
 86
 87OTP memory ("fuses") are used for secure boot and anti-rollback
 88protection. The OTP memory is ECC protected, ECC errors indicate
 89either manufacturing defect or part deteriorating with age.
 90
 91Statistics
 92----------
 93
 94TX MAC Interface
 95~~~~~~~~~~~~~~~~
 96
 97 - ``ptp_illegal_req``: packets sent to the NIC with PTP request bit set but routed to BMC/FW
 98 - ``ptp_good_ts``: packets successfully routed to MAC with PTP request bit set
 99 - ``ptp_bad_ts``: packets destined for MAC with PTP request bit set but aborted because of some error (e.g., DMA read error)
100
101TX Extension (TEI) Interface (TTI)
102~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
103
104 - ``tti_cm_drop``: control messages dropped at the TX Extension (TEI) Interface because of credit starvation
105 - ``tti_frame_drop``: packets dropped at the TX Extension (TEI) Interface because of credit starvation
106 - ``tti_tbi_drop``: packets dropped at the TX BMC Interface (TBI) because of credit starvation
107
108RXB (RX Buffer) Enqueue
109~~~~~~~~~~~~~~~~~~~~~~~
110
111 - ``rxb_integrity_err[i]``: frames enqueued with integrity errors (e.g., multi-bit ECC errors) on RXB input i
112 - ``rxb_mac_err[i]``: frames enqueued with MAC end-of-frame errors (e.g., bad FCS) on RXB input i
113 - ``rxb_parser_err[i]``: frames experienced RPC parser errors
114 - ``rxb_frm_err[i]``: frames experienced signaling errors (e.g., missing end-of-packet/start-of-packet) on RXB input i
115 - ``rxb_drbo[i]_frames``: frames received at RXB input i
116 - ``rxb_drbo[i]_bytes``: bytes received at RXB input i
117
118RXB (RX Buffer) FIFO
119~~~~~~~~~~~~~~~~~~~~
120
121 - ``rxb_fifo[i]_drop``: transitions into the drop state on RXB pool i
122 - ``rxb_fifo[i]_dropped_frames``: frames dropped on RXB pool i
123 - ``rxb_fifo[i]_ecn``: transitions into the ECN mark state on RXB pool i
124 - ``rxb_fifo[i]_level``: current occupancy of RXB pool i
125
126RXB (RX Buffer) Dequeue
127~~~~~~~~~~~~~~~~~~~~~~~
128
129   - ``rxb_intf[i]_frames``: frames sent to the output i
130   - ``rxb_intf[i]_bytes``: bytes sent to the output i
131   - ``rxb_pbuf[i]_frames``: frames sent to output i from the perspective of internal packet buffer
132   - ``rxb_pbuf[i]_bytes``: bytes sent to output i from the perspective of internal packet buffer
133
134RPC (Rx parser)
135~~~~~~~~~~~~~~~
136
137 - ``rpc_unkn_etype``: frames containing unknown EtherType
138 - ``rpc_unkn_ext_hdr``: frames containing unknown IPv6 extension header
139 - ``rpc_ipv4_frag``: frames containing IPv4 fragment
140 - ``rpc_ipv6_frag``: frames containing IPv6 fragment
141 - ``rpc_ipv4_esp``: frames with IPv4 ESP encapsulation
142 - ``rpc_ipv6_esp``: frames with IPv6 ESP encapsulation
143 - ``rpc_tcp_opt_err``: frames which encountered TCP option parsing error
144 - ``rpc_out_of_hdr_err``: frames where header was larger than parsable region
145 - ``ovr_size_err``: oversized frames
146
147Hardware Queues
148~~~~~~~~~~~~~~~
149
1501. RX DMA Engine:
151
152 - ``rde_[i]_pkt_err``: packets with MAC EOP, RPC parser, RXB truncation, or RDE frame truncation errors. These error are flagged in the packet metadata because of cut-through support but the actual drop happens once PCIE/RDE is reached.
153 - ``rde_[i]_pkt_cq_drop``: packets dropped because RCQ is full
154 - ``rde_[i]_pkt_bdq_drop``: packets dropped because HPQ or PPQ ran out of host buffer
155
156PCIe
157~~~~
158
159The fbnic driver exposes PCIe hardware performance statistics through debugfs
160(``pcie_stats``). These statistics provide insights into PCIe transaction
161behavior and potential performance bottlenecks.
162
1631. PCIe Transaction Counters:
164
165   These counters track PCIe transaction activity:
166        - ``pcie_ob_rd_tlp``: Outbound read Transaction Layer Packets count
167        - ``pcie_ob_rd_dword``: DWORDs transferred in outbound read transactions
168        - ``pcie_ob_wr_tlp``: Outbound write Transaction Layer Packets count
169        - ``pcie_ob_wr_dword``: DWORDs transferred in outbound write
170	  transactions
171        - ``pcie_ob_cpl_tlp``: Outbound completion TLP count
172        - ``pcie_ob_cpl_dword``: DWORDs transferred in outbound completion TLPs
173
1742. PCIe Resource Monitoring:
175
176   These counters indicate PCIe resource exhaustion events:
177        - ``pcie_ob_rd_no_tag``: Read requests dropped due to tag unavailability
178        - ``pcie_ob_rd_no_cpl_cred``: Read requests dropped due to completion
179	  credit exhaustion
180        - ``pcie_ob_rd_no_np_cred``: Read requests dropped due to non-posted
181	  credit exhaustion
182
183XDP Length Error:
184~~~~~~~~~~~~~~~~~
185
186For XDP programs without frags support, fbnic tries to make sure that MTU fits
187into a single buffer. If an oversized frame is received and gets fragmented,
188it is dropped and the following netlink counters are updated
189
190   - ``rx-length``: number of frames dropped due to lack of fragmentation
191     support in the attached XDP program
192   - ``rx-errors``: total number of packets with errors received on the interface