+
+
+Limitations or Known issues
+---------------------------
+
+Malicious Driver Detection not Supported
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The Intel x550 series NICs support a feature called MDD (Malicious
+Driver Detection) which checks the behavior of the VF driver.
+If this feature is enabled, the VF must use the advanced context descriptor
+correctly and set the CC (Check Context) bit.
+DPDK PF doesn't support MDD, but kernel PF does. We may hit problem in this
+scenario kernel PF + DPDK VF. If user enables MDD in kernel PF, DPDK VF will
+not work. Because kernel PF thinks the VF is malicious. But actually it's not.
+The only reason is the VF doesn't act as MDD required.
+There's significant performance impact to support MDD. DPDK should check if
+the advanced context descriptor should be set and set it. And DPDK has to ask
+the info about the header length from the upper layer, because parsing the
+packet itself is not acceptable. So, it's too expensive to support MDD.
+When using kernel PF + DPDK VF on x550, please make sure using the kernel
+driver that disables MDD or can disable MDD. (Some kernel driver can use
+this CLI 'insmod ixgbe.ko MDD=0,0' to disable MDD. Some kernel driver disables
+it by default.)
+
+
+Statistics
+~~~~~~~~~~
+
+The statistics of ixgbe hardware must be polled regularly in order for it to
+remain consistent. Running a DPDK application without polling the statistics will
+cause registers on hardware to count to the maximum value, and "stick" at
+that value.
+
+In order to avoid statistic registers every reaching the maximum value,
+read the statistics from the hardware using ``rte_eth_stats_get()`` or
+``rte_eth_xstats_get()``.
+
+The maximum time between statistics polls that ensures consistent results can
+be calculated as follows:
+
+.. code-block:: c
+
+ max_read_interval = UINT_MAX / max_packets_per_second
+ max_read_interval = 4294967295 / 14880952
+ max_read_interval = 288.6218096127183 (seconds)
+ max_read_interval = ~4 mins 48 sec.
+
+In order to ensure valid results, it is recommended to poll every 4 minutes.
+
+MTU setting
+~~~~~~~~~~~
+
+Although the user can set the MTU separately on PF and VF ports, the ixgbe NIC
+only supports one global MTU per physical port.
+So when the user sets different MTUs on PF and VF ports in one physical port,
+the real MTU for all these PF and VF ports is the largest value set.
+This behavior is based on the kernel driver behavior.
+
+
+Supported Chipsets and NICs
+---------------------------
+
+- Intel 82599EB 10 Gigabit Ethernet Controller
+- Intel 82598EB 10 Gigabit Ethernet Controller
+- Intel 82599ES 10 Gigabit Ethernet Controller
+- Intel 82599EN 10 Gigabit Ethernet Controller
+- Intel Ethernet Controller X540-AT2
+- Intel Ethernet Controller X550-BT2
+- Intel Ethernet Controller X550-AT2
+- Intel Ethernet Controller X550-AT
+- Intel Ethernet Converged Network Adapter X520-SR1
+- Intel Ethernet Converged Network Adapter X520-SR2
+- Intel Ethernet Converged Network Adapter X520-LR1
+- Intel Ethernet Converged Network Adapter X520-DA1
+- Intel Ethernet Converged Network Adapter X520-DA2
+- Intel Ethernet Converged Network Adapter X520-DA4
+- Intel Ethernet Converged Network Adapter X520-QDA1
+- Intel Ethernet Converged Network Adapter X520-T2
+- Intel 10 Gigabit AF DA Dual Port Server Adapter
+- Intel 10 Gigabit AT Server Adapter
+- Intel 10 Gigabit AT2 Server Adapter
+- Intel 10 Gigabit CX4 Dual Port Server Adapter
+- Intel 10 Gigabit XF LR Server Adapter
+- Intel 10 Gigabit XF SR Dual Port Server Adapter
+- Intel 10 Gigabit XF SR Server Adapter
+- Intel Ethernet Converged Network Adapter X540-T1
+- Intel Ethernet Converged Network Adapter X540-T2
+- Intel Ethernet Converged Network Adapter X550-T1
+- Intel Ethernet Converged Network Adapter X550-T2
git.droids-corp.org / dpdk.git / blobdiff