Known Issues
VF Network Function Limitations in SR-IOV Legacy Mode & in Switchdev Mode
Dual Port Device | Single Port Device |
127 VF per PF (254 functions) | 127 |
VF+SF Network Function Limitations in Switchdev Mode
Dual Port Device | Single Port Device |
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ConnectX-8 has the same feature set and limitations as ConnectX-7 adapter card. For the list of ConnectX-7 Known Issues, please go to https://docs.nvidia.com/networking/software/adapter-firmware/index.html#connectx-7.
The below are limitations related to ConnectX-8 only.
| Internal Ref. | Issue |
| 4604969 | Description: Probe packets might be dropped at the transmission stage when multiple congestion control flows are active. |
| Workaround: N/A | |
| Keywords: PCC, RTT, probe | |
| Detected in version: 40.47.1026 | |
| 4496642 | Description: The timestamps (t2, t4) of the received RTT probes are taken from the free-running clock, even when ROCE_CC_RTT_TIMESTAMP_FORMAT is set to 0x02. The format of all RTT probe timestamps can be found in HCA_CAP.rtt_timestamp_format. |
| Workaround: N/A | |
| Keywords: RTT RTC timestamp | |
| Detected in version: 40.47.1026 | |
| 4705241 | Description: When Quantum-2 is part of an XDR topology, serving as a leaf switch connected to NDR-based hosts, a bandwidth degradation of approximately 3–7 Gb/s is expected. |
| Workaround: N/A | |
| Keywords: XDR, NDR, Quantum-2 | |
| Detected in version: 40.47.1026 | |
| 4705948 | Description: When using DC as the InfiniBand transport type to perform an ib_read RDMA operation between ConnectX-7 (NDR) and ConnectX-8, a bandwidth degradation of approximately 25% may be observed when using a low number of QPs (1–16). The performance degradation diminishes as the number of QPs increases. |
| Workaround: N/A | |
| Keywords: DC, ib_read RDMA, NDR, performance | |
| Detected in version: 40.47.1026 | |
| 4685736 | Description: Creating a DPA process that allocates a 128 MB data segment and loads a dynamic library may fail with syndrome 0xdc30ac. |
| Workaround: Limit the DPA application’s data segment size to 64 MB. | |
| Keywords: DPA | |
| Detected in version: 40.47.1026 | |
| 4618452 | Description: When only a partial number of fiber lanes are connected to a module (i.e., not all supported lanes are populated), the module re-insertion process may experience an extended link-up time of approximately one minute. This occurs because the module requires additional time to detect that only a subset of the lanes is connected. |
| Workaround: N/A | |
| Keywords: Cables | |
| Detected in version: 40.47.1026 | |
| 4270913 | Description: For DC InfiniBand transport, using SRQs requires distributing QPs across four SRQs. Each QP must be assigned to its own SRQ when there are up to four QPs. |
| Workaround: If more than four QPs are used, they must be evenly distributed across the four available SRQs. | |
| Keywords: DC InfiniBand transport, SRQ, QPs | |
| Detected in version: 40.47.1026 | |
| 4665802 | Description: Due to a re-burst scheduler limitation, the expected “speed of light” value for single QP RDMA Write on ConnectX-8 devices cannot be calculated. Currently, verification is limited to identifying performance degradations relative to previous firmware versions. |
| Workaround: N/A | |
| Keywords: Single QP RDMA Write | |
| Detected in version: 40.47.1026 | |
| 4270913 | Description: When using DC InfiniBand transport, SRQ usage requires distributing QPs across four SRQs. This means assigning each QP to its own SRQ when there are up to four QPs. |
| Workaround: If there are more than four QPs, they must be distributed equally among the four available SRQs. | |
| Keywords: DC InfiniBand transport, SRQ, QPs | |
| Detected in version: 40.45.1200 | |
| 4031430 | Description: Connecting to systems with NRZ speeds of 1, 10, 25, 40, 50, or 100Gb/s is not supported. |
| Workaround: N/A | |
| Keywords: NRZ, Connectivity | |
| Detected in version: 40.45.1020 | |
| 4412310 | Description: Split operation (port splitting) on the second port is not supported on the ConnectX-8 SuperNIC model 900-9X81Q-00CN-ST0. |
| Workaround: N/A | |
| Keywords: Port splitting | |
| Detected in version: 40.45.1020 | |
| 4394475 | Description: The existing congestion control configuration applies globally, rather than on a per-priority basis. |
Workaround: Ensure that the configuration values for all priorities are aligned in either mlxconfig ROCE_CC_PRIO_MASK_P$port or sysfs ecn/roce_rp/enable/$port. | |
| Keywords: Congestion control, ROCE_CC_PRIO | |
| Detected in version: 40.45.1020 | |
| 4240828 | Description: Simultaneous access to the same PDDR module info page is not supported. |
| Workaround: N/A | |
| Keywords: PDDR module | |
| Detected in version: 40.45.1020 | |
| 4230775 | Description: Due to a known issue, telemetry rate must be set to lower than 3 minutes. |
| Workaround: N/A | |
| Keywords: Telemetry rate | |
| Detected in version: 40.44.0212 | |
| 4201405 | Description: Upgrading to firmware 40.44.0xxx from any previous Engineering Sample version requires power cycling the driver and not just resetting it (using mlxfwreset). |
| Workaround: N/A | |
| Keywords: Upgrade, power cycle, reset | |
| Detected in version: 40.44.0208 |