net/szedata2: do not affect Ethernet interfaces

[dpdk.git] / doc / guides / nics / szedata2.rst

diff --git a/doc/guides/nics/szedata2.rst b/doc/guides/nics/szedata2.rst
index 4327e4e..1b4b3eb 100644 (file)
--- a/doc/guides/nics/szedata2.rst
+++ b/doc/guides/nics/szedata2.rst
@@ -43,8 +43,10 @@ separately:
 
 *  **Kernel modules**
 
+   * combo6core
    * combov3
-   * szedata2_cv3
+   * szedata2
+   * szedata2_cv3 or szedata2_cv3_fdt
 
    Kernel modules manage initialization of hardware, allocation and
    sharing of resources for user space applications.
@@ -62,45 +64,53 @@ These configuration options can be modified before compilation in the
 
    Value **y** enables compilation of szedata2 PMD.
 
-*  ``CONFIG_RTE_LIBRTE_PMD_SZEDATA2_AS`` default value: **0**
-
-   This option defines type of firmware address space and must be set
-   according to the used card and mode.
-   Currently supported values are:
-
-   * **0** - for cards (modes):
-
-      * NFB-100G1 (100G1)
+Using the SZEDATA2 PMD
+----------------------
 
-   * **1** - for cards (modes):
+From DPDK version 16.04 the type of SZEDATA2 PMD is changed to PMD_PDEV.
+SZEDATA2 device is automatically recognized during EAL initialization.
+No special command line options are needed.
 
-      * NFB-100G2Q (100G1)
+Kernel modules have to be loaded before running the DPDK application.
 
-   * **2** - for cards (modes):
+NFB card architecture
+---------------------
 
-      * NFB-40G2 (40G2)
-      * NFB-100G2C (100G2)
-      * NFB-100G2Q (40G2)
+The NFB cards are multi-port multi-queue cards, where (generally) data from any
+Ethernet port may be sent to any queue.
+They were historically represented in DPDK as a single port.
 
-   * **3** - for cards (modes):
+However, the new NFB-200G2QL card employs an addon cable which allows to connect
+it to two physical PCI-E slots at the same time (see the diagram below).
+This is done to allow 200 Gbps of traffic to be transferred through the PCI-E
+bus (note that a single PCI-E 3.0 x16 slot provides only 125 Gbps theoretical
+throughput).
 
-      * NFB-40G2 (10G8)
-      * NFB-100G2Q (10G8)
+Since each slot may be connected to a different CPU and therefore to a different
+NUMA node, the card is represented as two ports in DPDK (each with half of the
+queues), which allows DPDK to work with data from the individual queues on the
+right NUMA node.
 
-   * **4** - for cards (modes):
+.. figure:: img/szedata2_nfb200g_architecture.svg
+    :align: center
 
-      * NFB-100G1 (10G10)
+    NFB-200G2QL high-level diagram
 
-   * **5** - for experimental firmwares and future use
+Limitations
+-----------
 
-Using the SZEDATA2 PMD
-----------------------
+The SZEDATA2 PMD does not support operations related to Ethernet ports
+(link_up, link_down, set_mac_address, etc.).
 
-From DPDK version 16.04 the type of SZEDATA2 PMD is changed to PMD_PDEV.
-SZEDATA2 device is automatically recognized during EAL initialization.
-No special command line options are needed.
+NFB cards employ multiple Ethernet ports.
+Until now, Ethernet port-related operations were performed on all of them
+(since the whole card was represented as a single port).
+With NFB-200G2QL card, this is no longer viable (see above).
 
-Kernel modules have to be loaded before running the DPDK application.
+Since there is no fixed mapping between the queues and Ethernet ports, and since
+a single card can be represented as two ports in DPDK, there is no way of
+telling which (if any) physical ports should be associated with individual
+ports in DPDK.
 
 Example of usage
 ----------------