Hello DPDK / net_ice maintainers,


We are seeing a reproducible and concerning issue when using the net_ice PMD with DPDK 22.11.2, and we would appreciate your help diagnosing it.


Summary
- Environment:
- DPDK: 22.11.2
- net_ice PCI device: 8086:159b
- ice kernel driver: 1.12.7
- NIC firmware: FW 7.3.6111681 (NVM 4.30)
- IOVA mode: PA, VFIO enabled
- Multi-process socket: /var/run/dpdk/PGW/mp_socket
- NUMA: 2, detected lcores: 112
- Bonding: pmd_bond with bonded devices created (net_bonding0 on port 4, net_bonding1 on port 5)
- Driver enabled AVX2 OFFLOAD Vector Tx (log shows "ice_set_tx_function(): Using AVX2 OFFLOAD Vector Tx")


- Problem statement:
- Our application calls rte_eth_tx_prepare before calling rte_eth_tx_burst as part of the normal transmission path.
- After the application has been running for some time (not immediate), the kernel/driver emits the following messages repeatedly:
- ice_interrupt_handler(): OICR: MDD event
- ice_interrupt_handler(): Malicious Driver Detection event 3 by TCLAN on TX queue 1025 PF# 1
- We are using a single TX queue (application-level single queue) and are sending only one packet per burst (burst size = 1).
- The sequence is: rte_eth_tx_prepare (returns) -> rte_eth_tx_burst -> MDD events occur later.
- The events affect stability and repeat over time.


Relevant startup logs (excerpt)
EAL: Detected CPU lcores: 112
EAL: Detected NUMA nodes: 2
EAL: Selected IOVA mode 'PA'
EAL: VFIO support initialized
EAL: Probe PCI driver: net_ice (8086:159b) device: 0000:3b:00.1 (socket 0)
ice_load_pkg_type(): Active package is: 1.3.45.0, ICE COMMS Package (double VLAN mode)
ice_dev_init(): FW 7.3.6111681 API 1.7
...
bond_probe(3506) - Initializing pmd_bond for net_bonding0
bond_probe(3592) - Create bonded device net_bonding0 on port 4 in mode 1 on socket 0.
...
ice_set_tx_function(): Using AVX2 OFFLOAD Vector Tx (port 0).
TELEMETRY: No legacy callbacks, legacy socket not created


What we have tried / preliminary observations
- Confirmed application calls rte_eth_tx_prepare prior to rte_eth_tx_burst.
- Confirmed single TX queue configuration and small bursts (size = 1) ¡ª not high-rate, not a typical high-burst/malicious pattern.
- The MDD log identifies "TX queue 1025";  unclear how that maps to our DPDK queue numbering (we use queue 0 in the app).
- No obvious other DPDK errors at startup;  interface initializes normally and vector TX is enabled.
- We suspect the driver's Malicious Driver Detection (MDD) is triggering due to some descriptor/doorbell ordering or offload interaction, possibly related to AVX2 Vector Tx offload.


Questions / requests to the maintainers
1.  What specifically triggers "MDD event 3 by TCLAN" in net_ice?  Which driver check/threshold corresponds to event type 3?
2.  How is the "TX queue 1025" value computed/mapped in the log?  (Is it queue id + offset, VF mapping, or an internal vector id?)  We need to map that log value to our DPDK queue index.
3.  Can the rte_eth_tx_prepare + rte_eth_tx_burst call pattern cause MDD detections under any circumstances?  If so, are there recommended usage patterns or ordering constraints to avoid false positives?
4.  Are there known firmware/driver/DPDK version combinations with similar MDD behavior?  Do you recommend specific NIC firmware, kernel driver, or DPDK versions as a workaround/fix?
5.  Any suggested workarounds we can test quickly (e.g., disable vector TX offload, disable specific HW offloads, change interrupt/queue bindings, or adjust doorbell behavior)?




Best regards.