trace: add trace configuration parameter

[dpdk.git] / doc / guides / contributing / design.rst

diff --git a/doc/guides/contributing/design.rst b/doc/guides/contributing/design.rst
index bac3d1b..d3dd694 100644 (file)
--- a/doc/guides/contributing/design.rst
+++ b/doc/guides/contributing/design.rst
@@ -1,15 +1,18 @@
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright 2018 The DPDK contributors
+
 Design
 ======
 
 Environment or Architecture-specific Sources
 --------------------------------------------
 
-In DPDK and DPDK applications, some code is specific to an architecture (i686, x86_64) or to an executive environment (bsdapp or linuxapp) and so on.
+In DPDK and DPDK applications, some code is specific to an architecture (i686, x86_64) or to an executive environment (freebsd or linux) and so on.
 As far as is possible, all such instances of architecture or env-specific code should be provided via standard APIs in the EAL.
 
 By convention, a file is common if it is not located in a directory indicating that it is specific.
 For instance, a file located in a subdir of "x86_64" directory is specific to this architecture.
-A file located in a subdir of "linuxapp" is specific to this execution environment.
+A file located in a subdir of "linux" is specific to this execution environment.
 
 .. note::
 
@@ -52,7 +55,7 @@ Per Execution Environment Sources
 The following config options can be used:
 
 * ``CONFIG_RTE_EXEC_ENV`` is a string that contains the name of the executive environment.
-* ``CONFIG_RTE_EXEC_ENV_BSDAPP`` or ``CONFIG_RTE_EXEC_ENV_LINUXAPP`` are defined only if we are building for this execution environment.
+* ``CONFIG_RTE_EXEC_ENV_FREEBSD`` or ``CONFIG_RTE_EXEC_ENV_LINUX`` are defined only if we are building for this execution environment.
 
 Library Statistics
 ------------------
@@ -78,7 +81,7 @@ are collected for any instance of any object type provided by the library:
 
 .. code-block:: console
 
-   # DPDK file config/common_linuxapp, config/common_bsdapp, etc.
+   # DPDK file config/common_linux, config/common_freebsd, etc.
    CONFIG_RTE_<LIBRARY_NAME>_STATS_COLLECT=y/n
 
 The default value for this DPDK configuration file variable (either "yes" or
@@ -158,3 +161,17 @@ cache bandwidth, memory bandwidth, etc) that depends on:
   branches are usually required. When processing a burst of packets that have been
   validated for header integrity, counting the number of bits set in a bitmask
   might be needed.
+
+PF and VF Considerations
+------------------------
+
+The primary goal of DPDK is to provide a userspace dataplane. Managing VFs from
+a PF driver is a control plane feature and developers should generally rely on
+the Linux Kernel for that.
+
+Developers should work with the Linux Kernel community to get the required
+functionality upstream. PF functionality should only be added to DPDK for
+testing and prototyping purposes while the kernel work is ongoing. It should
+also be marked with an "EXPERIMENTAL" tag. If the functionality isn't
+upstreamable then a case can be made to maintain the PF functionality in DPDK
+without the EXPERIMENTAL tag.