- - Currently it is not possible to use an Intel XL710 Network Interface as a
- DPDK port type on a platform with more than 64 logical cores. This is
- related to how DPDK reports the number of TX queues that may be used by
- a DPDK application with an XL710. The maximum number of TX queues supported
- by a DPDK application for an XL710 is 64. If a user attempts to add an
- XL710 interface as a DPDK port type to a system as described above the
- port addition will fail as OVS will attempt to initialize a TX queue greater
- than 64. This issue is expected to be resolved in a future DPDK release.
- As a workaround a user can disable hyper-threading to reduce the overall
- core count of the system to be less than or equal to 64 when using an XL710
- interface with DPDK.
+ - By default with DPDK 2.2, a maximum of 64 TX queues can be used with an
+ Intel XL710 Network Interface on a platform with more than 64 logical
+ cores. If a user attempts to add an XL710 interface as a DPDK port type to
+ a system as described above, an error will be reported that initialization
+ failed for the 65th queue. OVS will then roll back to the previous
+ successful queue initialization and use that value as the total number of
+ TX queues available with queue locking. If a user wishes to use more than
+ 64 queues and avoid locking, then the
+ `CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_PF` config parameter in DPDK must be
+ increased to the desired number of queues. Both DPDK and OVS must be
+ recompiled for this change to take effect.
+
+ vHost and QEMU v2.4.0+:
+ - For versions of QEMU v2.4.0 and later, it is currently not possible to
+ unbind more than one dpdkvhostuser port from the guest kernel driver
+ without causing the ovs-vswitchd process to crash. If this is a requirement
+ for your use case, it is recommended either to use a version of QEMU
+ between v2.2.0 and v2.3.1 (inclusive), or alternatively, to apply the
+ following patch to DPDK and rebuild:
+ http://dpdk.org/dev/patchwork/patch/7736/
+ This problem will likely be resolved in Open vSwitch at a later date, when
+ the next release of DPDK (which includes the above patch) is available and
+ integrated into OVS.